TOWN​ ​OF​ ​HOPKINTON PLANNING​ ​BOARD Monday​ ​September​ ​25,​ ​2017​ ​ ​7:00​ ​PM HCAM​ ​Studios,​ ​Studio​ ​A,​ ​Lower​ ​Level,​ ​77​ ​Main​ ​Street,​ ​Hopkinton,​ ​MA AGENDA

7:00

Continued​ ​Public​ ​Hearing​ ​-​ ​Saddle​ ​Hill​ ​Road​ ​Lots​ ​1-4​ ​-Scenic​ ​Road​ ​Permits​ ​-​ ​Saddle Hill​ ​Realty​ ​LLC Proposed​ ​removal​ ​of​ ​152​ ​ft.​ ​section​ ​of​ ​stone​ ​wall,​ ​over​ ​4​ ​lots​ ​within​ ​the​ ​layout​ ​of​ ​Saddle Hill​ ​Road​ ​for​ ​the​ ​construction​ ​of​ ​driveways​ ​to​ ​4-single​ ​family​ ​homes.

7:30

Continued​ ​Public​ ​Hearing​ ​-​ ​50-60​ ​West​ ​Main​ ​Street​ ​-Site​ ​Plan​ ​Review​ ​-​ ​Golden​ ​Pond Resident​ ​Care​ ​Corporation Proposed​ ​34,100​ ​sf​ ​addition​ ​to​ ​the​ ​existing​ ​building​ ​as​ ​part​ ​of​ ​the​ ​Phase​ ​3​ ​Golden​ ​Pond expansion​ ​project.

8:30

5​ ​Minute​ ​Break

8:35

Public​ ​Hearing​ ​–​ ​147​ ​Lumber​ ​Street​ ​ ​-​ ​Commercial​ ​Solar​ ​Photovoltaic​ ​Special Permit​ ​Application​ ​and​ ​Stormwater​ ​Management​ ​Permit​ ​Application​ ​-​ ​Clean​ ​Energy Collective Proposed​ ​2.9​ ​MW​ ​commercial​ ​solar​ ​photovoltaic​ ​installation​ ​on​ ​approximately​ ​11.4​ ​acres of​ ​land (Assessor’s​ ​Map​ ​R29-15-0​ ​and​ ​R30-1-A).

9:15

Public​ ​Hearing​ ​-​ ​97​ ​East​ ​Main​ ​Street​ ​-​ ​Minor​ ​Site​ ​Plan​ ​Review​ ​-​ ​Weston​ ​Nurseries Proposed​ ​construction​ ​of​ ​a​ ​3,200​ ​square​ ​foot​ ​greenhouse.

Business​ ​to​ ​be​ ​considered​ ​by​ ​the​ ​Board​ ​at​ ​any​ ​time​ ​during​ ​the​ ​meeting: ● Center​ ​School​ ​Re-Use​ ​Advisory​ ​Team​ ​Survey ● Request​ ​to​ ​Extend​ ​Time​ ​to​ ​Complete​ ​Construction​ ​of​ ​Legacy​ ​Farms​ ​South​ ​-​ ​Roy MacDowell ● Request​ ​for​ ​Minor​ ​Modification​ ​to​ ​Plan​ ​for​ ​Box​ ​Mill​ ​Road​ ​-​ ​Richard​ ​Barbieri ● Approve​ ​Minutes​ ​(​August​ ​28,​ ​2017​) ● Board​ ​member​ ​comments,​ ​reports,​ ​liaison​ ​reports,​ ​or​ ​future​ ​agenda​ ​items ● Correspondence

TOWN OF HOPKINTON DEPARTMENT OF

LAND USE, PLANNING AND PERMITTING TOWN HALL 18 MAIN STREET HOPKINTON, MA 01748 508-497-9745 www.hopkintonma.gov

DATE:

September 20, 2017

TO:

Planning Board

FROM:

Jennifer Burke, Principal Planner

RE:

Items on September 25, 2017 Planning Board Agenda

1. Continued Public Hearing – Saddle Hill Road Lots 1-5 – Scenic Road Permit This hearing has been continued from your last meeting. A majority vote is required for approval and a decision is due 21 days from the close of public hearing. Since the last meeting the developer’s engineer has met with the Fire Chief and they have come to an agreement regarding the driveways. Enclosed is an emergency vehicle exhibit for each driveway. The Fire Chief has also provided a letter indicating his support for the new design. The cumulative total of stone wall to be removed now is 133 linear feet. The Scenic Road By-law provides as follows: § 160-6. Criteria for work projects. The Planning Board’s decision on any application for proposed work affecting scenic roads shall be based on consideration of the following criteria: A. The degree to which the proposed work would adversely affect the scenic and aesthetic values upon which the scenic road designation was originally based. B. The necessity for the proposed work in terms of public safety, welfare, or convenience. C. Compensatory action proposed, such as replacement of trees or walls. D. Availability of reasonable alternatives to the proposed work which could reduce or eliminate anticipated damage to trees or stone walls. E. Whether the proposed work would compromise or harm other environmental or historical values.

F. Consistency of the proposed work with previously adopted Town plans and policies. 2. Continued Public Hearing – Site Plan Review – 50-60 West Main Street – Golden Pond This application for a Site Plan Review was continued from your meeting on August 28, 2017. A decision is due 90 days from the close of the public hearing, and a majority vote is required for approval. Cliff Kistner needs to review the tape and sign the affidavit in order to vote. All other members are eligible. I have updated the outline from the previous meeting (see enclosed). We will continue to follow the outline. The Site Plan Standards are attached to the end of the outline. The developer submitted updated information to us and BETA in early September. BETA has reviewed it and provided the enclosed comments. There still seems to be several outstanding issues remaining. We have received the following comments from other Town Departments: Bryan Besso Health Agent, Board of Health –The Board of Health does not have any issues with this project site plan review. The facility does not have a septic system and is on a public water supply. Thank you for offering our department an opportunity to comment. At a department head review meeting July 20, 2017 with representatives of the Police Dept., Fire Dept., DPW and myself, the following comments were made:  The DPW is evaluating the availability of water and should know something soon.  It should be determined if the internal site piping for sewage can meet the estimated flow.  The Fire Department had concerns relative to the Construction Management Plan including parking for construction workers vehicles, clear fire access maintained throughout the duration of the project and enforcement.  Fire protection calculations will need to be done by the Town’s fire protection engineer.  The Fire Department will need to review the whole project for access. There may be a challenging spot between Phase II and Phase III.  A swept path analysis with the parking will be required.  Hours of operation for construction should be noticed to all contractors and subcontractors. No idling before 7:00 AM.  Fire Department ambulance is currently rated at capacity. Depending on type of services in new Phase, could see up to an additional 108 calls per year.  Police & DPW should indicate if they have the institutional capacity to support the project. The Conservation Commission has continued their public hearing for a Notice of Intent until October 2nd pending ongoing BETA review. I have compiled the following in advance for the Board’s information: Board Action A. Vote to determine that the plan complies with the Site Plan Standards; 2

B. Vote to approve the site plan with conditions. Site Plan Standards My opinion as to compliance with the Site Plan Standards contained in Section 210-136.1 is indicated below. A. Site disturbance in wetland buffer zones and to slopes in excess of 25% shall be minimized. Complies. B. Unique natural and historic features shall be preserved whenever feasible. Complies. C. Tree, vegetation and soil removal shall be minimized. Complies. D. The site activities shown on the Site Plan shall be screened from view from abutting properties in residential use. Methods of screening may include solid fencing, landscaping or other proposals of the Applicant, subject to review by the Planning Board. Such screening may be located on or off-site. If located off-site, written permission of the off-site property owner shall be provided to the Board. Complies. E. All utilities shall be underground. Complies – Existing. F. Exposed storage areas, machinery, service areas, truck loading areas, utility buildings and structures and other similar uses shall be visually screened from abutting properties and those using public ways. Screening methods may consist of solid fencing, landscaping or similar proposals submitted by the Applicant, subject to review by the Planning Board. Complies. G. The site plan shall show measures to reduce and abate noise and odors generated from the site that will impact surrounding properties. Complies. H. The site plan shall comply with all zoning requirements. Complies. I. The site plan shall maximize the convenience and safety of vehicular and pedestrian movement within the site and to and from adjacent public ways. If supporting documentation, such as a traffic or parking study, submitted to the Planning Board indicates that the vehicular and pedestrian traffic movement depicted on the site plan and proposed in the application will have a significant negative impact or impacts on the site or within the adjacent ways, such impacts shall be mitigated by the Applicant. Complies – Existing. J. Parking areas shall be designed so that they are safe and convenient and do not detract from the use and enjoyment of proposed structures. Parking areas shall be designed to facilitate safe pedestrian access to the structures and other on-site facilities. Complies –Existing. K. The site plan shall minimize the number of curb cuts on public ways. Complies – Existing. L. Driveways shall be designed to ensure safe sight distances at interior and exterior intersections and along driveways, in accordance with applicable AASHTO requirements. Complies – Existing. M. Sidewalks shall be provided along the entire frontage of the subject property along existing public ways. The Planning Board may approve alternative provisions or waive the requirements of this Standard in situations where sidewalk construction or use is not feasible or practical. Complies – Existing. N. Levels of illumination shall be provided as follows: 1. No property may have exterior lighting that exceeds the average illumination level recommended by the Illuminating Engineering Society of North America for such use as set forth in “Lighting Facilities for Parking Facilities,” Illuminating Engineering Society, 2014 and “The Lighting Handbook,” 10th Ed., Illuminating Engineering Society, 2011. Complies – Existing.

3

2. For pole mounted lights in parking and driveway areas, the height of the light source shall not exceed 15 feet, which shall be measured from the ground at the base of the pole to the bottom of the fixture. Complies – Existing. 3. Pedestrian area lighting shall utilize fully shielded fixtures, and the height of light source shall not exceed 12 feet, measured from the ground at the base of the pole to the bottom of the fixture. Complies – Existing. 4. No exterior lighting may interfere with the safe movement of motor vehicles on public ways or private ways open to the public. Complies – Existing. 5. Mercury vapor lamps shall be prohibited. Complies – Existing. 6. Uplighting shall be permitted only when used in one of the following manners: Complies – Existing. (a) To light a primary entrance, when the fixture or lamp is wall-mounted under an architectural element (e.g., roofs over walkways, entries or overhanging, nontranslucent eaves) so that the uplighting is fully captured; (b) To light local, state or national flags; or (c) To highlight or illuminate a building facade or landscaping, or to highlight or illuminate statues or monuments. 7. Floodlighting shall be permitted only if a fully shielded fixture is utilized and no lighting will fall onto the property of others. Complies – Existing. 8. Safety and security lighting shall use motion sensors, photocells, or photocells or timers to control duration of nighttime illumination. Complies – Existing. 9. Exterior lighting of recreation facilities shall utilize fully shielded fixtures and, except as authorized by Special Permit or Site Plan Approval, shall be turned off by 10:00 p.m. or at the conclusion of an activity begun before 10:00 p.m.; provided, however, that in any event the exterior lighting shall be turned off by midnight. Not Applicable. 10. Blinking, flashing, moving, revolving and flickering lights, as well as lighting that changes intensity or color shall be prohibited except for lighting for public safety or traffic control and lighting required by the U.S. Federal Aviation Administration for air traffic control and warning purposes. Not Applicable. 11. Notwithstanding any provisions of this subsection to the contrary, sidewalks that run along the perimeter of a site and are in a public right of way or on abutting property may be illuminated, and illumination may spill onto abutting non-residential property if requested in writing by the abutting property owner. Complies – Existing. Exterior lighting that does not conform to the provisions of this subsection may be allowed by special permit from the Planning Board if the Planning Board finds that such exterior lighting will be consistent with the Purposes of this Article, or that there are other demonstrable community, health, safety or welfare benefits that will be served by the exterior lighting. No special permit may be granted pursuant to this subsection unless the Planning Board determines that the proposed exterior lighting is appropriate for the size and use of the property, any buildings thereon, and the neighborhood setting. O. Adequate access shall be provided to each structure for emergency vehicles and personnel. Complies – Existing. P. The site plan shall conform to applicable Massachusetts Department of Environmental Protection Storm water Management Regulations. The site plan shall show adequate measures to prevent pollution of surface water and groundwater, to minimize erosion and sedimentation and to prevent changes in the potential for flooding. Storm water management 4

facilities shall be designed so that neighboring properties, public ways and public storm drainage systems will not be adversely impacted. Complies. Q. Mechanical equipment or other utility hardware on the roof, grounds or buildings shall be screened from view from the ground. Complies. R. All dumpsters shall be screened from public view. Complies - Existing. Proposed Conditions: Below is a list of proposed conditions for the Board to consider prior to approval. There may be others that become apparent at the hearing the Board may want to add. 1. The applicant shall be responsible for mitigating all construction related impacts, including erosion, siltation and dust control in a timely manner. (Site Plan Standard G) 2. The applicant shall regularly remove construction trash and debris from the site in accordance with good construction practice. No tree stumps, demolition material, trash or debris shall be burned or buried on the site. (Site Plan Standard G) 3. In the event that the amount of snow on the Site exceeds the amount that can be accommodated safely in the snow storage areas indicated on the Site Plan, the excess snow shall be removed from the parking area. (Site Plan Standard J) 4. Mechanical equipment or other utility hardware on the roof, grounds or buildings shall be screened from view from the ground. (Site Plan Standard Q) 5. The Director of Municipal Inspections inspects Site Plans under construction for compliance with the approved Decision of Site Plan Review. If the Director of Municipal Inspections determines at any time before or during construction that a registered professional engineer or other such outside professional is required to assist with the inspections of the storm water management system or any other component of the Site Plan, the Applicant shall be responsible for the cost of those inspections. (All Site Plan Standards & § 210-137) 6. In accordance with § 210-138 of the Zoning Bylaw, the Applicant shall provide a performance guarantee in the amount of $3,000 to the Town prior to the commencement of construction pursuant to this Decision. The guarantee shall consist of a deposit of money or negotiable securities in a form selected by the Planning Board to guarantee that any unforeseen problems which arise, such as erosion and sedimentation and the correction of site lighting problems, are addressed. The funds will be held by the Town and returned to the Applicant upon completion of the project. (All Site Plan Standards & § 210-137) 7. Construction may occur only between the hours of 7:00 AM and 7:00 PM Monday through Friday and Saturdays between 8:00 AM and 4:00 PM pursuant to Chapter 141 Article 1 of the Town of Hopkinton General Bylaws.

5

3. Public Hearing – 147 Lumber Street – Commercial Solar Photovoltaic Special Permit Application and Stormwater Management Permit Application – Clean Energy Collective Two applications have been submitted to the Board, relative to the proposal to construct a 2.9 MW solar facility at 147 Lumber Street, and the two public hearings are being held concurrently:  Special Permit application pursuant to Zoning Bylaw Article XXXI – A decision is due 90 days from the close of the public hearing and a 2/3 vote is required for approval.  Stormwater Management Permit application pursuant to General Bylaw Chapter 172 – A decision is due by October 23, 2017 and a majority vote is required for approval. If the public hearing is continued, then an additional extension of time for the Board to file its decision may be required. The solar facility will be located on 11.4 acres out of the total 41.5 acres on the property at 147 Lumber Street. There is an existing residence on the property as well. The land is zoned Agricultural, and is also within the Water Resources Protection Overlay District (WRPOD-1). The surrounding use is primarily residential. However, the property also abuts the Sportsman’s Club. The solar facility will be accessed via the existing driveway off Lumber Street. The array will be surrounded by a fence. The applicant has filed a Notice of Intent with the Conservation Commission and their hearing is in process. I have complied a project outline and it is enclosed. BETA has provided the enclosed comments dated September 19, 2017 and covers both applications. This letter has been sent to the applicant and his engineer. No response has been received. Several of the lots on which the array is located are newly acquired. The applicant has also provided a draft ANR plan to combine the lots. This plan will be submitted if the Board indicates a favorable action on the Special Permit. This is to avoid a violation of setbacks from interior lot lines. Approval Criteria – Special Permit Before the Planning Board issues a special permit, it must determine the following:  The commercial solar photovoltaic installation conforms to the provisions of Article XXXI of the Zoning Bylaw (listed below, abbreviated); A. Three acre minimum parcel; B. Setback, yard, buffer and screening requirements applicable in the zoning district apply; C. Security fences shall be set back from the property line a distance equal to the setback requirement applicable to buildings within the zoning district in which the installation is located; D. Site Plan Review is not required; 6

  

E. The visual impact of the installation, including all accessory structures and appurtenances, shall be mitigated. All accessory structures and appurtenances shall be architecturally compatible with each other. Whenever reasonable, structures shall be shielded from view by vegetation and /or joined and clustered to avoid adverse visual impacts. Methods such as the use of landscaping, natural features and fencing may be used. F. Lighting shall not be permitted unless required by the Planning Board or by the State Building Code. Where used, lighting shall be directed downward and full cut-off fixtures shall be used. G. All utility connections from the installation shall be underground unless otherwise specifically permitted by the Board in the special permit. Electrical transformers and inverters to enable utility interconnections may be above ground if required by the utility provider. H. Clearing of natural vegetation shall be limited to the minimum necessary for the construction, operation and maintenance of the commercial solar photovoltaic installation except as otherwise prescribed by applicable laws, regulations and bylaws or the special permit. I. The installation owner or operator shall maintain the facility in good condition. Maintenance shall include painting, structural repairs, continued compliance with landscaping and screening requirements, and integrity of security measures. The owner or operator shall be responsible for the maintenance of any access roads serving the installation. The commercial solar photovoltaic installation will not be detrimental to the neighborhood or the Town; Environmental features of the site and surrounding areas are protected, and specifically surrounding areas will be protected from the proposed use by provision of adequate surface water drainage; Grant of the special permit will be in harmony with the general purpose and intent of the Bylaw.

The Board must give due consideration to promoting the public health, safety, convenience and welfare; and shall not permit a use that is injurious, noxious, offensive or detrimental to its neighborhood except as otherwise specified in the bylaw (Sec. 210-223). Special permits shall be subject to whatever appropriate conditions and safeguards the Board may prescribe. The Board’s authority in this matter is tempered by the provisions of MGL c.40A Sec. 3, which states “No zoning ordinance or bylaw shall prohibit or unreasonably regulate the installation of solar energy systems or the building of structures that facilitate the collection of solar energy, except where necessary to protect the public health, safety or welfare.” The Attorney General advised the Town in its approval of the solar bylaw of the following: A. “These special permit standards in Section 210-203 (D) appear to be consistent with the Town’s general zoning power and the power to impose reasonable regulations on solar 7

uses “where necessary to protect the public health, safety or welfare.” G.L. c. 40, § 3. However, the Town should consult closely with Town Counsel throughout the special permit review process to ensure that the standards in Section 210-203 (D) are not applied in a manner that contravenes the protections granted to solar energy systems in G.L. c. 40A, § 3.” B. “Section 210-203 (E) authorizes the Planning Board to impose conditions and other safeguards on a special permit issued for a Solar Installation. Specifically, Section 210203 (E) authorizes the Planning Board to require a performance bond, or other type of security deposit to guarantee proper maintenance and removal of the Solar Installation. Any financial surety requirements imposed by the Planning Board do not become Town funds unless and until the applicant defaults on the obligation imposed under the by-law or special permit. If the Town must use the financial surety to pay for work required under the bylaw or special permit, the Town must appropriate the funds before an expenditure is made to do the work. General Laws Chapter 44, Section 53, provides that “[a]ll moneys received by a city, town or district officer or department, except as otherwise provided by special acts and except fees provided for by statute, shall be paid by such officers or department upon their receipt into the city, town or district treasury.” Under Section 53 all moneys received by the Town become part of the general fund, unless the Legislature has expressly made other provisions that are applicable to such moneys. In the absence of any general or special law to the contrary, performance security funds of the sort contemplated in Section 210-203 (E) must be deposited with the Town Treasurer and made part of the Town’s general fund pursuant to G.L. c. 44, § 53. The Town must then appropriate the money for the specific purpose of complying with the conditions relating to removal of the Solar Installation. We suggest that the Town discuss the application of this section.” Approval Criteria - Stormwater Management Permit BETA Group has reviewed the application and has provided the enclosed letter report. The project is subject to the DEP Stormwater Management Standards. The following are the 10 standards and BETA’s comments with respect to relative compliance provided by the submitted documentation: Stormwater Standard BETA comments on proposed plan Compliance #1 – No untreated stormwater The project does not propose untreated Complies – No new stormwater stormwater discharges to wetlands. conveyances (e.g. outfalls) may discharge untreated stormwater directly to or cause erosion in wetlands or waters of the Commonwealth. #2 – Post-development peak The model for the proposed condition Additional discharge rates – Stormwater uses a meadow, non-grazed to information management systems must be approximate the surface characteristic needed designed so that postwhen fully constructed. However, once development peak discharge constructed, the surface will not receive rates do not exceed prerainfall evenly. 8

development peak discharge rates. #3 – Recharge to groundwater – Loss of annual recharge to groundwater should be minimized through the use of infiltration measures to the maximum extent practicable. #4 – 80% Total Suspended Solids (TSS) removal – For new development, stormwater management systems must be designed to remove 80% of the annual load of total suspended solids. #5 – Higher Potential Pollutant Loads – Stormwater discharges from land uses with Higher Potential Pollutant Loads required the use of specific stormwater management BMP’s. #6 – Critical Areas – Stormwater discharges to critical areas must utilize certain stormwater BMP’s approved for critical areas. #7 – Redevelopment – Redevelopment of previously developed sites must meet the Stormwater Management Standards to the maximum extent practicable. #8 – Construction Period Erosion and Sediment Controls – Erosion and sediment controls must be implemented to prevent impacts during construction of land disturbance activities. #9 – Operations/Maintenance Plan – A long-term operation and maintenance plan shall be developed and implemented to ensure that stormwater

The site is predominately comprised of soils rated in Hydrologic Soil Groups A and B in upland areas.

Additional information needed

Stormwater runoff from the site discharges to the adjacent wetland areas. The plan include recharge infiltration basins to provide recharge.

Complies

Not applicable

Not applicable

Project is not likely to generate pollutants that would adversely impact groundwater supplies. It provides treatment of runoff and recharge via infiltration basins.

Complies

Not applicable

Not applicable

The project site is greater than 1 acre in area and land disturbance activities will require a NOI with EPA and a SWPPP.

Additional information needed

An O & M Plan was included in the drainage report.

Additional information needed

9

management systems function as designed. #10 – Illicit Discharges – All illicit discharges to the stormwater management systems are prohibited.

An unsigned illicit discharge statement has been provided.

Additional information needed

With respect to Planning Board action, the Stormwater Regulations adopted by the Board in 2008 states: The Planning Board’s action, rendered in writing, shall consist of either: 1. Approval of the SMP application based upon determination that the proposed plan meets the Standards in Section 7.0, will adequately protect the water resources of the community and is in compliance with the requirements set forth in the Bylaw and the Regulations, 2. Approval of the SMP application subject to any conditions, modifications or restrictions required by the Planning Board which will ensure that the project meets the Standards in Section 7.0 and adequately protects water resources, set forth in the Bylaw and the Regulations, 3. Disapproval of the SMP application based upon a determination that the proposed plan, as submitted, does not meet the Standards in Section 7.0, does not adequately protect water resources, or does not comply with the provisions of the Bylaw or the Regulations. 4. The Planning Board may disapprove an application “without prejudice” where an applicant fails to provide requested additional information or review fees that in the Planning Board’s opinion are needed to adequately describe or review the proposed project. See the table above for the referenced criteria. Standard SMP conditions are attached to the end of this memo. 4. Public Hearing –Minor Site Plan – 97 Main Street – New Greenhouse The application for a Minor Site Plan was submitted on September 8, 2017. A decision is due on November 7, 2017, and a majority vote is required for approval. The proposed alterations include the installation of a 3,200 sf greenhouse. The building will be located between the garden center and the shed. It will be on a slab 5 ft deep. No additional traffic is anticipated. No changes to stormwater are proposed. No changes to parking are proposed. There will be internal lighting and no new signs. The project is seeking a minor site plan review because the amount of square footage being changed is less than 5,000. Under this review the Board can determine whether or not BETA review is necessary. There are no impacts to the storm water or traffic and parking. The changes are all architectural. It would appear that a BETA review is not warranted for this application. We have received the following comments from other Town Departments: 10

Shaun McAuliffe, BOH Director, Board of Health – No comments or concerns for the proposed facility. The proposed structure does not require septic and/or water service. Design Review Board met on Tuesday September 19, 2017 and had no recommendations. I have compiled the following in advance for the Board’s information: Board Action A. Vote to determine that the project meets the requirements of a Minor Project under §210-134; B. Vote to determine that the plan complies with the Site Plan Standards; C. Vote to approve the site plan with conditions. Site Plan Standards My opinion as to compliance with the Site Plan Standards contained in Section 210-136.1 is indicated below. A. Site disturbance in wetland buffer zones and to slopes in excess of 25% shall be minimized. Not Applicable - No disturbance. B. Unique natural and historic features shall be preserved whenever feasible. Complies. C. Tree, vegetation and soil removal shall be minimized. Complies. D. The site activities shown on the Site Plan shall be screened from view from abutting properties in residential use. Methods of screening may include solid fencing, landscaping or other proposals of the Applicant, subject to review by the Planning Board. Such screening may be located on or off-site. If located off-site, written permission of the off-site property owner shall be provided to the Board. Complies. E. All utilities shall be underground. Complies F. Exposed storage areas, machinery, service areas, truck loading areas, utility buildings and structures and other similar uses shall be visually screened from abutting properties and those using public ways. Screening methods may consist of solid fencing, landscaping or similar proposals submitted by the Applicant, subject to review by the Planning Board. Complies. G. The site plan shall show measures to reduce and abate noise and odors generated from the site that will impact surrounding properties. Complies. H. The site plan shall comply with all zoning requirements. Complies I. The site plan shall maximize the convenience and safety of vehicular and pedestrian movement within the site and to and from adjacent public ways. If supporting documentation, such as a traffic or parking study, submitted to the Planning Board indicates that the vehicular and pedestrian traffic movement depicted on the site plan and proposed in the application will have a significant negative impact or impacts on the site or within the adjacent ways, such impacts shall be mitigated by the Applicant. Complies – Existing. J. Parking areas shall be designed so that they are safe and convenient and do not detract from the use and enjoyment of proposed structures. Parking areas shall be designed to facilitate safe pedestrian access to the structures and other on-site facilities. Complies –Existing. K. The site plan shall minimize the number of curb cuts on public ways. Complies – Existing. L. Driveways shall be designed to ensure safe sight distances at interior and exterior intersections and along driveways, in accordance with applicable AASHTO requirements. Complies – Existing. 11

M. Sidewalks shall be provided along the entire frontage of the subject property along existing public ways. The Planning Board may approve alternative provisions or waive the requirements of this Standard in situations where sidewalk construction or use is not feasible or practical. Complies – Existing. N. Levels of illumination shall be provided as follows: 1. No property may have exterior lighting that exceeds the average illumination level recommended by the Illuminating Engineering Society of North America for such use as set forth in “Lighting Facilities for Parking Facilities,” Illuminating Engineering Society, 2014 and “The Lighting Handbook,” 10th Ed., Illuminating Engineering Society, 2011. Complies – Existing. 2. For pole mounted lights in parking and driveway areas, the height of the light source shall not exceed 15 feet, which shall be measured from the ground at the base of the pole to the bottom of the fixture. Complies – Existing. 3. Pedestrian area lighting shall utilize fully shielded fixtures, and the height of light source shall not exceed 12 feet, measured from the ground at the base of the pole to the bottom of the fixture. Complies – Existing. 4. No exterior lighting may interfere with the safe movement of motor vehicles on public ways or private ways open to the public. Complies – Existing. 5. Mercury vapor lamps shall be prohibited. Complies – Existing. 6. Uplighting shall be permitted only when used in one of the following manners: Complies – Existing. (a) To light a primary entrance, when the fixture or lamp is wall-mounted under an architectural element (e.g., roofs over walkways, entries or overhanging, nontranslucent eaves) so that the uplighting is fully captured; (b) To light local, state or national flags; or (c) To highlight or illuminate a building facade or landscaping, or to highlight or illuminate statues or monuments. 7. Floodlighting shall be permitted only if a fully shielded fixture is utilized and no lighting will fall onto the property of others. Complies – Existing. 8. Safety and security lighting shall use motion sensors, photocells, or photocells or timers to control duration of nighttime illumination. Complies – Existing. 9. Exterior lighting of recreation facilities shall utilize fully shielded fixtures and, except as authorized by Special Permit or Site Plan Approval, shall be turned off by 10:00 p.m. or at the conclusion of an activity begun before 10:00 p.m.; provided, however, that in any event the exterior lighting shall be turned off by midnight. Not Applicable. 10. Blinking, flashing, moving, revolving and flickering lights, as well as lighting that changes intensity or color shall be prohibited except for lighting for public safety or traffic control and lighting required by the U.S. Federal Aviation Administration for air traffic control and warning purposes. Not Applicable. 11. Notwithstanding any provisions of this subsection to the contrary, sidewalks that run along the perimeter of a site and are in a public right of way or on abutting property may be illuminated, and illumination may spill onto abutting non-residential property if requested in writing by the abutting property owner. Complies – Existing. Exterior lighting that does not conform to the provisions of this subsection may be allowed by special permit from the Planning Board if the Planning Board finds that such exterior lighting will be consistent with the Purposes of this Article, or that there are other 12

O. P.

Q. R.

demonstrable community, health, safety or welfare benefits that will be served by the exterior lighting. No special permit may be granted pursuant to this subsection unless the Planning Board determines that the proposed exterior lighting is appropriate for the size and use of the property, any buildings thereon, and the neighborhood setting. Adequate access shall be provided to each structure for emergency vehicles and personnel. Complies – Existing. The site plan shall conform to applicable Massachusetts Department of Environmental Protection Storm water Management Regulations. The site plan shall show adequate measures to prevent pollution of surface water and groundwater, to minimize erosion and sedimentation and to prevent changes in the potential for flooding. Storm water management facilities shall be designed so that neighboring properties, public ways and public storm drainage systems will not be adversely impacted. Complies – Existing. Mechanical equipment or other utility hardware on the roof, grounds or buildings shall be screened from view from the ground. Not Applicable All dumpsters shall be screened from public view. Not Applicable.

Site Plan Vote & Conditions: Find that the site plan complies with the Site Plan Standards contained in § 210-136.1 with the conditions to be imposed, and approve the Site Plan with the conditions below. 1. The applicant shall be responsible for mitigating all construction related impacts, including erosion, siltation and dust control in a timely manner. (Site Plan Standard G) 2. The applicant shall regularly remove construction trash and debris from the site in accordance with good construction practice. No tree stumps, demolition material, trash or debris shall be burned or buried on the site. (Site Plan Standard G) 3. Mechanical equipment or other utility hardware on the roof, grounds or buildings shall be screened from view from the ground. (Site Plan Standard Q) 4. The Director of Municipal Inspections inspects Site Plans under construction for compliance with the approved Decision of Site Plan Review. If the Director of Municipal Inspections determines at any time before or during construction that a registered professional engineer or other such outside professional is required to assist with the inspections of the storm water management system or any other component of the Site Plan, the Applicant shall be responsible for the cost of those inspections. (All Site Plan Standards & § 210-137) 5. In accordance with § 210-138 of the Zoning Bylaw, the Applicant shall provide a performance guarantee in the amount of $3,000 to the Town prior to the commencement of construction pursuant to this Decision. The guarantee shall consist of a deposit of money or negotiable securities in a form selected by the Planning Board to guarantee that any unforeseen problems which arise, such as erosion and sedimentation and the correction of site lighting problems, are addressed. The funds will be held by the Town and returned to the Applicant upon completion of the project. (All Site Plan Standards & § 210-137)

13

6. Construction may occur only between the hours of 7:00 AM and 7:00 PM Monday through Friday and Saturdays between 8:00 AM and 4:00 PM pursuant to Chapter 141 Article 1 of the Town of Hopkinton General Bylaws.

5. Legacy Farms South Subdivision Extension The subdivision approval for Legacy Farms South includes the following condition: 10. Roadway and infrastructure construction shown on the Subdivision Plan shall be completed within five (5) years from the start of construction or this approval shall be automatically rescinded unless such time is extended by the Board at the request of the Applicant. If construction has not commenced within five (5) years from the date of this approval, such approval shall be automatically rescinded. Construction began in October 2011. Last year the Board granted an extension through September 30, 2017. Since the work will not be completed until the end of the year per Mr. McDowell’s letter, the Board will need to issue an extension of time to complete the work. He has requested until June 15, 2018. 6. Request for Minor Modification to Box Mill Road Mr. Barbieri is requesting a modification to the approved plan for Box Mill Road. The approved plan shows a farmers wall along the edge of pavement, up one side and around the cul-de-sac. He would like to change this to a masonry wall using the same stones and stopping before the last driveway. The Board needs to determine if the modifications are major or minor. If minor, the Board can review and vote with no further notice. If major, the Board needs to schedule a new hearing and notices need to go out. It would appear from a planning perspective, that the changes are minor in nature. 7. Future Meetings October 16 October 30 November 13 November 27

14

Article XXXI Commercial Solar Photovoltaic Installations [Added 5-6-2013 ATM Article 57; Amended 5-4-2015 ATM Article 39] § 210-200. Purpose and Intent The purpose and intent of this Article is to permit the creation of new commercial solar photovoltaic installations by providing standards for the placement, design, construction, operation, monitoring, modification and removal of such installations that address public safety and minimize impacts on residential neighborhoods and scenic, natural and historic resources. § 210-201. Applicability Construction and use of a commercial solar photovoltaic installation or any part thereof shall be permitted in any zoning district subject to the requirements set forth in this section. Nothing in this Article should be construed to prevent the installation of solar photovoltaic installations that are permitted as-ofright in any zoning district as an accessory use. § 210-202. Use Regulations Commercial solar photovoltaic installations shall conform to the following provisions: A.

A commercial solar photovoltaic installation may be erected, upon the issuance of a special permit by the Planning Board, on a lot containing a minimum of three (3) acres.

B.

All setback, yard, buffer and screening requirements applicable in the zoning district in which the installation is located shall apply.

C.

All security fences surrounding the installations shall be set back from the property line a distance equal to the setback requirement applicable to buildings within the zoning district in which the installation is located.

D.

The provisions of Article XX, Site Plan Review, shall not apply to commercial solar photovoltaic installations.

E.

The visual impact of the commercial solar photovoltaic installation, including all accessory structures and appurtenances, shall be mitigated. All accessory structures and appurtenances shall be architecturally compatible with each other. Whenever reasonable, structures shall be shielded from view by vegetation and/or joined and clustered to avoid adverse visual impacts. Methods such as the use of landscaping, natural features and fencing may be utilized.

F.

Lighting shall not be permitted unless required by the Planning Board or by the State Building Code. Where used, lighting shall be directed downward and full cut-off fixtures shall be used.

G.

All utility connections from the commercial solar photovoltaic installation shall be underground unless otherwise specifically permitted otherwise by the Planning Board in the special permit. Electrical transformers and inverters to enable utility interconnections may be above ground if required by the utility provider.

H.

Clearing of natural vegetation shall be limited to the minimum necessary for the construction, operation and maintenance of the commercial solar photovoltaic installation except as otherwise prescribed by applicable laws, regulations and bylaws or the special permit.

I.

The commercial solar photovoltaic installation owner or operator shall maintain the facility in good condition. Maintenance shall include, but not be limited to, painting, structural repairs, continued compliance with landscaping and screening requirements, and integrity of security measures. The owner or operator shall be responsible for the maintenance of any access roads serving the installation.

§ 210-203. Administration A.

A special permit is required from the Planning Board to erect or install a commercial solar photovoltaic installation. A record owner desiring to erect or install a commercial solar photovoltaic installation shall file with the Planning Board an application for a special permit, together with such plans, drawings, specifications, fees and additional information as required by the Planning Board.

15

B.

The Planning Board shall have the authority to waive specific provisions of the Use Regulations of this Article upon a determination that a waiver would not be inconsistent with the purpose and intent of this Article.

C.

The Planning Board shall conduct its review, hold a public hearing and file its decision with the Town Clerk as required by the provisions of this Chapter.

D.

Approval Criteria. Before the Planning Board may issue such a special permit, it shall determine each of the following: (1)

The commercial solar photovoltaic installation conforms to the provisions of this Article.

(2)

The commercial solar photovoltaic installation will not be detrimental to the neighborhood or the Town.

(3)

Environmental features of the site and surrounding areas are protected, and specifically surrounding areas will be protected from the proposed use by provision of adequate surface water drainage.

E.

Any special permit issued pursuant to this Article shall be subject to such conditions and safeguards as the Planning Board may prescribe. Such conditions may include the requirement of a performance bond, secured by deposit of money or negotiable securities, posted with the Town to guarantee proper maintenance and/or removal of the commercial solar photovoltaic installation. The amount of the performance bond shall not exceed the estimated cost of the commercial solar photovoltaic installation’s removal. Such conditions may also include additional screening of the facility.

§ 210-204. Discontinuance A commercial solar photovoltaic installation shall be deemed to have been discontinued if it has not been in service for a continuous 24-month period. Upon receipt of a Notice of Discontinuance from the Director of Municipal Inspections, the owner shall have the right to respond to the Notice within 30 days of receipt. The Director of Municipal Inspections shall withdraw the Notice of Discontinuance and notify the owner that the Notice has been withdrawn if the owner provides information that demonstrates to the satisfaction of the Director of Municipal Inspections that the commercial solar photovoltaic installation has not been discontinued. If the commercial solar photovoltaic installation is determined to be discontinued, the owner shall remove the installation, including all structures, equipment, security barriers and transmission lines, and stabilize or re-vegetate the site as necessary to minimize erosion and sedimentation, at the owner’s sole expense within three months of receipt of the Notice of Discontinuance. Failure to remove the installation and stabilize the site within said time period may subject the owner to action pursuant to Article XXIV.

Article XXXIV Special Permit Granting Authority [Added 5-4-2015 ATM Article 39] § 210-223. Special Permits. A.

Pursuant to MGL c. 40A, § 9, the Special Permit Granting Authority (SPGA) shall hear and decide applications for Special Permits for which express provision is made in this Chapter. The SPGA may be the Board of Appeals or the Planning Board.

B.

The SPGA shall adopt rules not inconsistent with the General Laws and the provisions of this Chapter for conducting its business and shall file a copy thereof with the Town Clerk.

C.

A Special Permit shall lapse within two years of the grant thereof unless good cause is shown why substantial use thereof, or related construction, has not begun; provided, however, that an applicant may request an extension of the term of a Special Permit from the SPGA, and the SPGA may extend such term as it deems appropriate.

D.

Public hearings on all applications for Special Permits shall be held in accordance with MGL c. 40A, § 11.

E.

The decision of the SPGA shall be made within 90 days after the close of the public hearing. The required time limits for a public hearing and the filing of a decision may be extended by written agreement between the applicant and the SPGA, and shall be filed with the Town Clerk.

F.

Failure of the SPGA to act within the specified period shall be deemed to be a grant of the Special Permit.

G.

Unless otherwise specified in this Chapter, a special permit may be granted only if the SPGA determines that:

16

(1) All applicable criteria and standards set forth in this Chapter have been satisfied, and (2) Grant of the Special Permit will be in harmony with the general purpose and intent of this Chapter. H.

In reviewing an application for a Special Permit, the SPGA shall give due consideration to promoting the public health, safety, convenience and welfare; and shall not permit a use that is injurious, noxious, offensive or detrimental to its neighborhood except as otherwise specified in this Chapter.

I.

Special permits shall be subject to whatever appropriate conditions and safeguards the SPGA may prescribe.

Stormwater Management Permit – Standard Conditions 1.

All erosion and sediment controls shall comply with the following performance criteria: a.

Minimize total area of disturbance and protect natural features and soil.

b.

Sequence activities to minimize simultaneous areas of disturbance. Mass clearings and grading of the entire site shall be avoided.

c.

Minimize peak rate of runoff in accordance with the Massachusetts Stormwater Standards.

d.

Minimize soil erosion and control sedimentation during construction, provided that prevention of erosion is preferred over sedimentation control.

e.

Divert uncontaminated water around disturbed areas.

f.

Maximize groundwater recharge.

g.

Install and maintain all Erosion and Sediment Control measures in accordance with the manufacturer’s specifications and good engineering practices.

h.

Prevent off-site transport of sediment.

i.

Protect and manage on and off-site material storage areas (overburden and stockpiles of dirt, borrow areas, or other areas used solely by the permitted project are considered a part of the project).

j.

Comply with applicable Federal, State and local laws and regulations including waste disposal, sanitary sewer or septic system regulations, and air quality requirements, including dust control.

k.

Prevent significant alteration of habitats mapped by the Massachusetts Natural Heritage & Endangered Species Program as Endangered, Threatened or Of Special Concern, Estimated Habitats of Rare Wildlife and Certified Vernal Pools, and Priority Habitats of Rare Species from the proposed activities.

l.

Institute interim and permanent stabilization measures, which shall be instituted on a disturbed area as soon as practicable but no more than 14 days after construction activity has temporarily or permanently ceased on that portion of the site.

m. Properly manage on-site construction and waste materials.

2.

n.

Prevent off-site vehicle tracking of sediments.

o.

Dust shall be controlled at the site.

p.

Divert offsite runoff from highly erodible soils and steep slopes to stable areas.

The project shall comply with the following Erosion and Sediment Control requirements: a.

Prior to any land disturbance activities commencing on the site, the developer shall physically mark limits of no land disturbance on the site with tape, signs, or orange construction fence, so that workers can see the areas to be protected. The physical markers shall remain in place until a Certificate of Completion has been issued.

17

b.

Appropriate erosion and sediment control measures shall be installed prior to soil disturbance. Measures shall be taken to control erosion within the project area. Sediment in runoff water shall be trapped and retained within the project area. Wetland areas and surface waters shall be protected from sediment.

c.

Sediment shall be removed once the volume reaches ¼ to ½ the height of a hay bale. Sediment shall be removed from silt fence prior to reaching the load-bearing capacity of the silt fence which may be lower than ¼ to ½ the height.

d.

Sediment from sediment traps or sedimentation ponds shall be removed when design capacity has been reduced by 50 percent.

e.

Soil stockpiles must be stabilized or covered at the end of each workday. Stockpile side slopes shall not be greater than 2:1. All stockpiles shall be surrounded by sediment controls.

f.

Disturbed areas remaining idle for more than 14 days shall be stabilized with seeding, wood chips, bark mulch, tarpaulins, or any other approved methods.

g.

For active construction areas such as borrow or stockpile areas, roadway improvements and areas within 50 feet of a building under construction, a perimeter sediment control system shall be installed and maintained to contain soil.

h.

A tracking pad or other approved stabilization method shall be constructed at all entrance/exit points of the site to reduce the amount of soil carried onto roadways and off the site.

i.

Permanent seeding shall be undertaken in the spring from March through May, and in late summer and early fall from August to October 15. During the peak summer months and in the fall after October 15, when seeding is found to be impractical, appropriate temporary stabilization shall be applied. Permanent seeding may be undertaken during the summer if plans provide for adequate mulching and watering.

j.

All slopes steeper than 3:1 (h:v, 33.3%), as well as perimeter dikes, sediment basins or traps, and embankments must, upon completion, be immediately stabilized with sod, seed and anchored straw mulch, or other approved stabilization measures. Areas outside of the perimeter sediment control system must not be disturbed.

k.

Temporary sediment trapping devices must not be removed until permanent stabilization is established in all contributory drainage areas.

l.

All temporary erosion and sediment control measures shall be removed after final site stabilization. Disturbed soil areas resulting from the removal of temporary measures shall be permanently stabilized within 30 days of removal.

3.

A minimum of seven days prior to the start of construction, a detailed construction sequence shall be submitted to the Hopkinton Director of Land Use, Planning and Permitting by the site contractor for review and approval. The approved construction sequence shall be followed throughout the course of the construction and shall be altered only with prior review by and written approval from the Director of Land Use, Planning and Permitting.

4.

All required SWPPP Stormwater Construction Site Inspection Reports shall be submitted to the Director of Land Use, Planning and Permitting within 14 days of each inspection.

5.

An adequate stockpile of erosion control materials shall be on site at all times for emergency or routine replacement and shall include materials to repair or replace silt fences, hay bales, stone filters, berms or any other devices planned for use during construction.

6.

The disturbed area at [insert address] shall be temporarily stabilized by hydroseeding if construction of the approved [insert plan type, if any] is not commenced within 30 days of lot clearing.

7.

[insert name(s) of abutting street(s)] in the vicinity of the project shall be swept as needed throughout the construction process.

8.

Compliance with the Operations and Maintenance Plan with respect to the cleaning of stormwater management system components will require the use of equipment which tends to generate significant noise. Due to the location of the site adjacent to a residential neighborhood and the provisions of Chapter 141 of the Bylaws of the Town of Hopkinton (“Noise”), the use of such equipment shall be restricted to the hours of operation contained in said Bylaw.

18

Jennifer Burke

Saddle Hill Road Scenic Road Permit Wayne Belec Tue, Sep 19, 2017 at 1:46 PM To: Jennifer Burke Cc: John Parsons , Victor Galvani , Nate Bautz , Larry Greene

Jen-

Please find the attached electronic version of the vehicle turning movement exhibit as requested. We trust that you will find that this information addresses the comments and concerns raised by the Board last week. Paper copies are being delivered shortly.

Thank you for your attention to this supplemental information and we look forward to seeing you next Monday night to briefly discuss and close the public hearing.

-Wayne

Wayne Belec Senior Project Manager/Business Development

WDA DESIGN GROUP CIVIL ENGINEERS

LANDSCAPE ARCHITECTS

SURVEYORS

PLANNERS

CELEBRATING 20 YEARS… NEW NAME, SAME VISION.

Please note our new company name and my new email address. We’ve changed the name of our two offices to WDA Design Group. My new email address is [email protected]. Our new website is www.wda-dg.com. When you have a moment, please update our contact information and check out our new website.

From: Jennifer Burke [mailto:[email protected]] Sent: Tuesday, September 19, 2017 9:33 AM To: Wayne Belec [Quoted text hidden] [Quoted text hidden]

All email messages and attached content sent from and to this email account are public records unless qualified as an exemption under the Massachusetts Public Records Law.

Visit us online at www.hopkintonma.gov.

1066200AT EXHIBIT (2017-09-19).pdf 780K

PUBLIC HEARING OUTLINE SITE PLAN REVIEW 50-60 WEST MAIN STREET An application for Site Plan Review has been filed. The Applicant proposes to construct a 34,100 square foot addition to the existing building as part of “phase 3”. √ Principal Planner Overview of Site and Project √ Project introduction and review - Applicant √ Principal Planner Comments √ Consultant Review – BETA Group √ Other Town Departments Comments √ Add to Outline - Planning Board members and Public Detailed Discussion a. √ Traffic b. √ Building Design c. Stormwater management d. √ Parking Lot Design (1) Snow Storage e. Lighting f. Landscaping/Screening g. Utilities h. √ Construction Management Plan 8. Review by Other Boards/Committees a. Conservation Commission b. √ Design Review Board 9. Public comment/Discuss site plan standards and plan revisions to be made 10. Discuss conditions of approval with applicant 11. Public comment 12. Vote on Site Plan approval and conditions 13. Close public hearing 1. 2. 3. 4. 5. 6. 7.

§ 210-136.1 Site Plan Standards The site plan shall be designed to conform to the following Site Plan Standards: A. Site disturbance in wetland buffer zones and to slopes in excess of 25% shall be minimized. B. Unique natural and historic features shall be preserved whenever feasible. C. Tree, vegetation and soil removal shall be minimized. D. The site activities shown on the Site Plan shall be screened from view from abutting properties in residential use. Methods of screening may include solid fencing, landscaping or other proposals of the Applicant, subject to review by the Planning Board. Such screening may be located on or off-site. If located off-site, written permission of the off-site property owner shall be provided to the Board. E. All utilities shall be underground. F. Exposed storage areas, machinery, service areas, truck loading areas, utility buildings and structures and other similar uses shall be visually screened from abutting properties and those using public ways. Screening methods may consist of solid fencing, landscaping or similar proposals submitted by the Applicant, subject to review by the Planning Board. G. The site plan shall show measures to reduce and abate noise and odors generated from the site that will impact surrounding properties. H. The site plan shall comply with all zoning requirements. I. The site plan shall maximize the convenience and safety of vehicular and pedestrian movement within the site and to and from adjacent public ways. If supporting documentation, such as a traffic or parking study, submitted to the Planning Board indicates that the vehicular and pedestrian traffic movement depicted on the site plan and proposed in the application will have a significant negative impact or impacts on the site or within the adjacent ways, such impacts shall be mitigated by the Applicant. J. Parking areas shall be designed so that they are safe and convenient and do not detract from the use and enjoyment of proposed structures. Parking areas shall be designed to facilitate safe pedestrian access to the structures and other on-site facilities. K. The site plan shall minimize the number of curb cuts on public ways. L. Driveways shall be designed to ensure safe sight distances at interior and exterior intersections and along driveways, in accordance with applicable AASHTO requirements. M. Sidewalks shall be provided along the entire frontage of the subject property along existing public ways. The Planning Board may approve alternative provisions or waive the requirements of this Standard in situations where sidewalk construction or use is not feasible or practical. N. Levels of illumination shall be provided as follows: [Amended 5-6-2015 ATM. Art. 36] (1) No property may have exterior lighting that exceeds the average illumination level recommended by the Illuminating Engineering Society of North America for such use as set forth in “Lighting Facilities for Parking Facilities,” Illuminating Engineering Society, 2014 and “The Lighting Handbook,” 10 th Ed., Illuminating Engineering Society, 2011. (2) For pole mounted lights in parking and driveway areas, the height of the light source shall not exceed 15 feet, which shall be measured from the ground at the base of the pole to the bottom of the fixture. (3) Pedestrian area lighting shall utilize fully shielded fixtures, and the height of light source shall not exceed 12 feet, measured from the ground at the base of the pole to the bottom of the fixture. (4) No exterior lighting may interfere with the safe movement of motor vehicles on public ways or private ways open to the public. (5) Mercury vapor lamps shall be prohibited. (6) Uplighting shall be permitted only when used in one of the following manners: (a) To light a primary entrance, when the fixture or lamp is wall-mounted under an architectural element (e.g., roofs over walkways, entries or overhanging, nontranslucent eaves) so that the uplighting is fully captured; (b) To light local, state or national flags; or (c) To highlight or illuminate a building facade or landscaping, or to highlight or illuminate statues or monuments. (7) Floodlighting shall be permitted only if a fully shielded fixture is utilized and no lighting will fall onto the property of others. (8) Safety and security lighting shall use motion sensors, photocells, or photocells or timers to control duration of nighttime illumination.

(9) Exterior lighting of recreation facilities shall utilize fully shielded fixtures and, except as authorized by Special Permit or Site Plan Approval, shall be turned off by 10:00 p.m. or at the conclusion of an activity begun before 10:00 p.m.; provided, however, that in any event the exterior lighting shall be turned off by midnight. (10) Blinking, flashing, moving, revolving and flickering lights, as well as lighting that changes intensity or color shall be prohibited except for lighting for public safety or traffic control and lighting required by the U.S. Federal Aviation Administration for air traffic control and warning purposes. (11) Notwithstanding any provisions of this subsection to the contrary, sidewalks that run along the perimeter of a site and are in a public right of way or on abutting property may be illuminated, and illumination may spill onto abutting non-residential property if requested in writing by the abutting property owner.

O. P.

Q. R.

Exterior lighting that does not conform to the provisions of this subsection may be allowed by special permit from the Planning Board if the Planning Board finds that such exterior lighting will be consistent with the Purposes of this Article, or that there are other demonstrable community, health, safety or welfare benefits that will be served by the exterior lighting. No special permit may be granted pursuant to this subsection unless the Planning Board determines that the proposed exterior lighting is appropriate for the size and use of the property, any buildings thereon, and the neighborhood setting. Adequate access shall be provided to each structure for emergency vehicles and personnel. The site plan shall conform to applicable Massachusetts Department of Environmental Protection Stormwater Management Regulations. The site plan shall show adequate measures to prevent pollution of surface water and groundwater, to minimize erosion and sedimentation and to prevent changes in the potential for flooding. Stormwater management facilities shall be designed so that neighboring properties, public ways and public storm drainage systems will not be adversely impacted. Mechanical equipment or other utility hardware on the roof, grounds or buildings shall be screened from view from the ground. All dumpsters shall be screened from public view.

J.D. MARQUEDANT & ASSOCIATES INC. Land Surveying 6 Walcott Street Hopkinton MA 01748 Phone: 508-435-4145 Fax: 508-435-0157 September 7, 2017 Ms. Jennifer Burke, Principal Planner Town of Hopkinton Planning Board 18 Main Street Hopkinton MA 01748 Re: "The Lofts" at Golden Pond 50 West Main Street Dear Jennifer: I am in receipt of a letter from BETA Group Inc. dated July 24, 2017 regarding project designs for the Golden Pond Medical Care Facility Phase 3 addition. Based on concerns raised in that letter, project designs have been revised. I offer the following summary of the project design revisions: 





Article VII - Rural Business (BR) District: Z1: Radner Design Associates has been retained to prepare Landscape plans for the proposed addition. The plans will be forwarded to your office as soon as they become available. Article XII - Water Resources Protection Overlay District: WR1. Soil testing was recently completed in several areas on the project site to assess the soil composition and estimated season high ground water levels. The stormwater management system has been revised based on the soil testing information. A closed drainage system of catch basins, manholes and piping will convey stormwater to a proposed forebay and retention basin at the northerly end of the project site. The forebay has an outlet structure which will release stormwater to the retention basin. Both the forebay and basin have been designed with a four foot or greater offset to estimated seasonal high groundwater. The existing drainage system will continue to carry the foundation drain flow only. The proposed stormwater management system has been designed to meet the DEP Stormwater Management Regulations. The plans have been revised to include elements of the stormwater management system and the supporting calculations have been updated to reflect the changes to project designs. (see sheets C-2 thru C-5 and C-8). Article XX: Site Plan Review: SP1. Photogrammetric analysis was completed as part of the previous submission for the site. Additional walk lighting and building mounted lighting information has been included with the revised designs. (see sheet C-7).





SP4: The designs have been revised to relocate the existing sanitary sewer force main should there be a conflict with the proposed building footing or foundation system and a typical trench section construction detail is included in the revised designs. (see sheets C-4 and C-6). SP5: The principals at The Golden Pond Resident Care Corp. are the owners of the parcel at 62 West Main Street and have control over the parcel. A lease agreement between the two parties has been developed and has been submitted to the Town of Hopkinton Planning Board for review Stormwater Management:

  

SW6: Riprap Pad calculations have been provided and are contained within the attached stormwater report SW11: Soil test data from testing conducted August 9, 2017 has been included in the revised designs. (see Sheet C-4) SW22: Access has been provided along the westerly property line to the basin and forebay. Construction materials will be organized and relocated if necessary to insure long term access for inspection and maintenance activities

Please contact me regarding any concerns you may have. Thank you for your attention to this matter. Sincerely, Joseph P. Marquedant J.D. Marquedant & Associates Inc. Cc: Kerry Kunst

September 19, 2017 Town of Hopkinton Planning Board Land Use, Planning, and Permitting Department 18 Main Street Hopkinton, MA 01748 Attn.: Ms. Jennifer Burke, Principal Planner Re:

Site Plan Review Update for The Golden Pond Residential Care Corporation – Hopkinton, MA

Dear Ms. Burke: BETA Group, Inc. (BETA) reviewed supplemental/revised documents for the Application for Approval of Site Plan Review for the The Golden Pond Resident Care Corporation. This letter is provided to update BETA’s findings, comments and recommendations. BASIS OF REVIEW The following supplemental/revised documents were received by BETA and formed the basis of the review: · · · ·

Response to comments letter to the Planning Board dated September 7, 2017 from J.D. Marquedant & Associates Inc., Hopkinton, MA Letter to the Hopkinton DPW requesting approval of water usage for the project dated July 17, 2017 from J.D. Marquedant & Associates Inc. Site Plans (9 sheets) entitled “The Lofts at Golden Pond” dated May 15, 2017 revised to September 7, 2017, prepared by J.D Marquedant & Associates Inc. and others Stormwater Report and Drainage Calculations Golden Pond Medical Care Facility 50 West Main Street in Hopkinton MA dated May 23, 2017, revised to September 5, 2017 prepared by Mark Piermarini

COMPILED REVIEW LETTER KEY BETA reviewed this project previously and provided review comments in letters to the Board dated June 26, 2017 and July 24, 2017 (original comments in italics), J.D. Marquedant & Associates Inc. (JDMAII) provided responses (responses in standard text) and BETA has provided comments on the status of each (status in bold italics). INTRODUCTION The site is currently developed with an existing 103,763 square foot (sq. ft.) medical care facility, site access drive, parking areas, utilities and stormwater management system.

BETA GROUP, INC. nd 315 Norwood Park South, 2 Floor, Norwood, MA 02062 P: 781.255.1982 | F: 781.255.1974 | W: www.BETA-Inc.com

Town of Hopkinton September 19, 2017 Page 2 of 9 The submitted documents indicate a proposed 34,100± sq. ft. building addition that would add 54 beds to the facility. The proposed use, health services facility, is permitted within the district. No changes to the site access or parking facilities are proposed. The project proposes work within wetland resource areas that requires conforming to the Massachusetts Wetlands Protection Act and Hopkinton Wetlands Protection Bylaw and obtaining an Order of Conditions from the Hopkinton Conservation Commission. The project is proposing stormwater management system expansion which will need to comply with the MassDEP Stormwater Management Standards and the Hopkinton Stormwater Management Bylaw and regulations. ZONING Article VII – Rural Business (BR) District The project is located on a previously developed lot and work proposed is part of Phase 3 of the Golden Pond Continuing Care Retirement Community. The project previously received approval through a Special Permit by the Town of Hopkinton Board of Appeals, with a decision recorded on November 18, 2009 for the following uses: “Continuing Care Retirement Community,” “Special Care Residences,” “Acute Care Services,” and “Rehabilitation Clinic.” The project reviewed in 2009 authorized a Special Permit for a phase project in two stages: Phase 2 and Phase 3. The lot is located within the Rural Business (BR) District Zone. The proposed building expansion use will encompass the previously approved uses for the facility and no change is anticipated. These uses (§21024.A.(5): Continuing Care Retirement Community Facilities/Assisted Living Facilities/Nursing Home Facilities) are allowed through a Special Permit. With the addition of the proposed building expansion the project continues to meet the requirements for minimum lot area, maximum lot coverage, street line setback, side and rear yard setbacks, and height. Loading zone is provided at the side of the building. Landscaping has been shown on provided plans and the landscaping along the street frontage is not anticipated to be modified. Z1.

Landscape plans, dated 2011, show proposed landscaping for building expansion and work along West Main Street. Provide plans showing any plants proposed for current proposed work and how any screening will be provided adjacent to the residential district. BETA2: No response or additional information provided – issue remains outstanding. JDMAI2: Radner Design Associates has been retained to prepare Landscape plans for the proposed addition. The plans will be forwarded to your office as soon as they become available. BETA3: Landscape plans not provided – issue remains outstanding

Article XII – Water Resources Protection Overlay District The site is also located within the Water Resource Overlay District (WRPOD-1). The proposed continued uses are permitted within the overlay district. The building expansion is proposed to increase the impervious areas to the site by 10,000± sq. ft. of new pavement and roof surfaces. The Applicant is providing recharge through the expansion of the existing retention basin. A sediment forebay is proposed to be installed upstream of the retention basin. WR1.

Wet basins and constructed stormwater wetlands are not BMPs that provide groundwater recharge (MassDEP Stormwater Standards, Volume 2, Chapter 1, Page 36). Provide MassDEP approved recharge BMP to satisfy providing groundwater recharge. See comment SW9. JDMAI1: The basin is a retention basin which utilizes recharge. The calculations have been revised to use an "A" soil type.

Town of Hopkinton September 19, 2017 Page 3 of 9 Copies of the revised calculations are attached to this letter. BETA2: During recent site visit, water was observed up to invert elevation of outlet which indicates that this BMP functions as a constructed stormwater wetland. Provide an infiltration BMP as required – issue remains outstanding. JDMAI2: Soil testing was recently completed in several areas on the project site to assess the soil composition and estimated season high ground water levels. The stormwater management system has been revised based on the soil testing information. A closed drainage system of catch basins, manholes and piping will convey stormwater to a proposed forebay and retention basin at the northerly end of the project site. The forebay has an outlet structure which will release stormwater to the retention basin. Both the forebay and basin have been designed with a four foot or greater offset to estimated seasonal high groundwater. The existing drainage system will continue to carry the foundation drain flow only. The proposed stormwater management system has been designed to meet the DEP Stormwater Management Regulations. The plans have been revised to include elements of the stormwater management system and the supporting calculations have been updated to reflect the changes to project designs. (see sheets C-2 thru C-5 and C-8). BETA3: Additional soil test pit provided – issue resolved. Article XVIII - Supplementary Regulations (as applicable) §210-124 Off Street Parking There are approximately 127± existing parking spaces at the site, 8 of which are handicapped accessible. The project is proposing no change to the number of parking spaces based on the proposed building spaces. Section 210-124.B.(1) states that Continuing Care Retirement Facility/Assisted Living/Nursing Home Facilities require 1 parking space for every 3 beds, plus 1 bed for each employee on the largest shift. Decision dated December 2009 allowed for the variance relief of a total of 14 parking spaces (8 for Phase 2 and 6 for Phase 3). Based on the proposed beds and employees resulting from the building expansion and taking into account the prior relief granted, 115 spaces are required at the site. Minimum number of handicapped accessible spaces is 5 which are met at the site. Z2.

Revise parking summary on Page 3 to reflect the parking space requirement relief granted by the Board. JDMAI1: The parking summary has been revised to reflect the relief granted by the Board of Appeals (see sheet C-3). BETA2: Parking summary revised – issue resolved.

Article XX – Site Plan Review §210-136.1 Site Plan Standards Work includes the new building, minor site work, utility modifications, and stormwater management features. There are no recorded historical features located at the site. Proposed utilities are shown underground. No new curb cuts expected for the site. New sight lighting is provided along the northern edge of the building but no photogrammetric analysis has been conducted. Noise and odors are expected to be similar to that of the existing buildings at the site. The Site Plan complies with Zoning except as noted above. See appropriate sections for comments on Zoning and Stormwater Management. SP1.

Provide photogrammetric analysis of proposed building to analyze spillage onto adjacent properties. BETA2: No response or additional information provided – issue remains outstanding. JDMAII: Photogrammetric analysis was completed as part of the previous submission for the site. Additional walk lighting and building mounted lighting information has been included with the revised designs. (see sheet C-7). BETA3: No photogrammetric analysis has been provided BETA defers to the Board on this issue.

Town of Hopkinton September 19, 2017 Page 4 of 9 SP2.

Town of Hopkinton Police and Fire Departments should confirm that there is adequate access around buildings and safety around parking lot during construction as shown on Plan C-9 Construction Summary Plan of Land (§210-136.O). BETA2: No response or additional information provided – issue remains outstanding. BETA3: No response or additional information provided – issue remains outstanding.

SP3.

Information has been provided showing approval for sewage increase from Town of Hopkinton Water and Sewer Department. Provide similar information that sufficient fire and potable water supplies are available for the building expansion. JDMAI1: Sufficient municipal water is available for the project. A formal request has been made to the Department of Public works regarding potable water. A copy of the request is attached to this letter. BETA2: Documentation with Department of Public Works provided. BETA defers to the forthcoming response of the Department of Public Works.

SP4.

Sewer forcemain is shown to be approximately 2 feet away from the proposed building corner. It is likely this will be impacted during construction. Provide plan to protect or relocate forcemain or replacement in case of disturbance. JDMAI1: The designs have been revised to relocate the existing sanitary sewer force main should there be a conflict with the proposed building footing or foundation system. (see sheet C-4). BETA2: Sewer forcemain shown to be relocated. Provide typical trench section detail for sewer forcemain. JDMAI2: The designs have been revised to relocate the existing sanitary sewer force main should there be a conflict with the proposed building footing or foundation system and a typical trench section construction detail is included in the revised designs. (see sheets C-4 and C-6). BETA3: Trench detail provided – issue resolved.

SP5.

About 15% of the existing parking spaces will be impacted by construction activities. Identify if this deficit will impact operations at the facility and recommend providing additional parking as needed. In addition, identify location of proposed construction trailer referenced in the Construction Management Plan to verify additional impact to parking spaces. JDMAI1: The location of the proposed construction trailer has been added to the revised design plans (see sheet C-9). It is anticipated that the twenty three (23) spaces associated with the Phase 3 addition will allow for site parking during the construction era for the addition. The twenty three spaces will not be necessary for staff and residents use until the construction is complete and will be available for use. BETA2: Location of trailer added to plans. Temporary parking area shown on plans on adjacent 62 West Main Street lot. Provide documentation indicating permission to use area for parking. JDMAI2: The principals at The Golden Pond Resident Care Corp. are the owners of the parcel at 62 West Main Street and have control over the parcel. A lease agreement between the two parties has been developed and has been submitted to the Town of Hopkinton Planning Board for review. BETA3: Explanation provided – issue resolved.

SP6.

Provide details of proposed retaining wall south of the new building expansion. BETA2: Details not included in resubmission – issue remains outstanding. BETA3: Details not included in the resubmission – issue remains outstanding.

TRAFFIC ASSESSMENT REVIEW Access to the site will be through the existing driveways, no new curb cuts are proposed for the site. Observed site distances are adequate. The new expansion of 54 beds will reportedly generate an additional 220 weekday daily trips, with an additional 10 weekday AM Peak Hour trips and 16 and weekday PM Peak Hour trips.

Town of Hopkinton September 19, 2017 Page 5 of 9 STORMWATER MANAGEMENT BETA visited the site to confirm limits of the drainage areas at the site, characteristics, and existing surface conditions. The proposed building is located north and west of the existing building location. The area is currently a grass lawn with concrete walkways adjacent to this area. The rest of the site has been developed with existing care facility buildings, parking, driveway, grassed open space, an existing pond, and landscaped features. NRCS classifications for soils (Web Soil Survey Version 16, September 14, 2016) indicate the site is majority Narragansett silt loam with a hydrologic soil group rating of A (high infiltration potential) Portions northeast of the site adjacent to the existing stormwater basin contains Ridgebury fine sandy loam with a HSG of D (minimal infiltration potential). BETA also notes that there was standing water observed in the basin which may indicate the presence of high groundwater, poor infiltration or that maintenance may be necessary. The design proposes to capture, treat, and infiltrate stormwater runoff from the proposed impervious areas via a roof drains, route flow to a new sediment forebay, and into an expanded extended detention / retention basin. Overflow is shown to be provided by the installation of both a new 15 and 12 inch HDPE over flow pipes. Riprap emergency spillway is proposed to be extended. A Stormwater Management Permit (SMP) conforming to the Town of Hopkinton Stormwater Regulations is required from the Planning Board based on the proposed construction activity disturbing more than one area of land as shown on the provided plans. In addition, the project is part of a master plan that will disturb more than one acre (§172-2.B(1)). A Stormwater Management Plan is required as part of the permit submission and the applicant has included a Stormwater Report and Drainage Calculations. SW1.

Provide Contact Information and Tax Reference Parcel identification number of the properties affected in the Drainage Report and Stormwater Management Plan (Appendix B.1). BETA2: Information not provided – issue remains outstanding. BETA3: Contact information provided in the Inspection and Maintenance Plan of the Drainage Report and Stormwater Management Plan. Tax Reference Parcel information provided on the design plans – issue resolved.

SW2.

Provide locus map in the Drainage Report and Stormwater Management Plan (Appendix B.3). JDMAI1: A locus map is contained within the Stormwater Report and calculations in the "Soils" section and the "FEMA" section. BETA2: Map provided in the Soils section and FEMA section – issue resolved.

SW3.

Provide delineation of 100-year flood plain. Available FEMA mapping is in conflict with the boundary shown on the plans (e.g. FEMA shows Zone A around ice house dam while plans do not show this / illegible) (Appendix B.12). JDMAI1: The delineation of the 100-year flood plain from available FEMA mapping has been added to the revised design plans. (see sheet C-2). BETA2: Limit added to plans – issue resolved.

SW4.

Provide drainage area maps for pre- and post-development conditions (Appendix B.15). JDMAI1: The Pre and Post development subcatchment maps have been provided and are attached to this letter. BETA2: Watershed maps provided – issue resolved.

SW5.

Provide additional spot grades for forebay top and bottom and all spillways part of the stormwater management system. JDMAI1: Additional spot grades at locations around the stormwater mitigation elements. Additional notes regarding the forebay and basin elevations have been added to the revised design plans. (see sheets C-4 and C-5). BETA2: Additional proposed grading added to plans – issue resolved. BETA3: Revised forebay and detention basin grading is very difficult to follow, provide detail of each at a smaller scale (1” = 10’) for review.

Town of Hopkinton September 19, 2017 Page 6 of 9 Massachusetts Stormwater Management Standards: The project is subject to the Stormwater Management Standards (Stormwater Regulations (SWR) 7.0). The following are the 10 standards and relative compliance provided by the submitted documentation. No untreated stormwater (Standard Number 1): No new stormwater conveyances (e.g., outfalls) may discharge untreated stormwater directly to or cause erosion in wetlands or waters of the Commonwealth. The project does not propose untreated stormwater discharges to wetlands. Runoff from new impervious areas are proposed to be routed to the reconstructed retention basin and discharged through three outlet pipes. SW6.

Provide calculations for sizing riprap pad outlets associated with the new drainage pipes (12” and 15” HDPE) adjacent to the existing wetland. JDMAI1: Riprap Pad calculations have been provided and are contained within the attached stormwater report. BETA2: Calculations not included – issue remains outstanding. JDMAII: Riprap Pad calculations have been provided and are contained within the attached stormwater report. BETA3: Riprap pad calculations provided – issue resolved.

Post-development peak discharge rates (Standard Number 2): Stormwater management systems must be designed so that post-development peak discharge rates do not exceed pre-development peak discharge rates. Calculations provided indicate the project will not increase in peak runoff flow for the 2, 10, 25, and 100 year storm events. In addition, data provided shows runoff volumes decreasing between pre- and postdevelopment conditions. SW7.

NRCS Web Soil Survey (Version 16, September 14, 2016) indicates that majority of project site is within HSG A soils. Revise modeling to include A soils in analysis. JDMAI1: The calculations have been revised to utilize an A soil type. BETA2: Proposed modeling conditions not updated – issue remains outstanding. BETA3: Soils type updated in the modeling – issue resolved.

SW8.

HydroCAD model indicates oscillating condition for the existing basin (outlet flow is higher than inlet flow) for the 100 year storm event. Adjust model to eliminate this condition. JDMAI1: The stormwater drainage calculations have been revised accordingly. BETA2: Proposed modeling conditions not updated – issue remains outstanding. BETA3: The following need to be address for the new design: a. Existing drain system mapping is incomplete; provide information for interior courtyard area, Phase 1 roof drains, DMH at southeast building corner…. b. Add to existing model the catchment area and routing of flow through the small pond where proposed forebay is located and verify that oscillations in existing basin are eliminated. c. Provide detail and explanation of “pipe through manhole”. d. Check pipe conflict of drain pipes crossing near DMH 4A e. Update pre development model to subdivide catchment area 4A and model pond near dumpster f.

SW9.

Update post development model to include new 24 inch bypass pipe and provide explanation as to the size.

Proposed Detention Basin (Pond 7P) is modeled to include exfiltration. Based on observing standing water in the basin, it may not be empty between storms reducing storage area and limiting exfiltration. Review model and update as necessary after gathering additional soil test data. JDMAI1: The bottom of the basin may need to be scoured out and cleaned from sediment buildup over time.

Town of Hopkinton September 19, 2017 Page 7 of 9 Any sediment build up will inhibit exfiltration. BETA2: Provided test pit data shows soil to be sandy loam material, a high HSG B material. Notes shall be placed on the plans outlining these measures to restore infiltration capacity of basin – issue remains outstanding. BETA3: No explanation for observations of standing water was provided. Revised design shows pipe to bypass basin. SW10. Peak elevation of Pond 7P: Proposed detention basin is elevation 368.20 whereas top of system modeled is elevation 369. Revise model to include 1 foot of freeboard and plans to ensure top of basin is minimum elevation 369.2 around. Complete similar model modifications for existing condition. JDMAI1: The drainage calculations will be revised accordingly. BETA2: Proposed modeling conditions not updated – issue remains outstanding. BETA3: One foot of freeboard provided around basin – issue resolved. Recharge to groundwater (Standard Number 3): Loss of annual recharge to groundwater should be minimized through the use of infiltration measures to maximum extent practicable. Recharge is proposed to be provided utilizing the regraded detention/retention basin. NRCS Web Soil Survey mapping shows the site comprised of Narragansett silt loam (HSG A) and Ridgebury fine sandy loam (HSG D). No test pits have been conducted and no information has been provided detailing soil type and estimated seasonal high groundwater. However, hydrologic modeling and recharge calculations are provided using an assumption that the soils are rated in HSG B. SW11. Provide soil test data within limits of stormwater BMP to identify seasonal high groundwater elevations and to confirm soil classification. JDMAI1: Soil test data from September 2012 and July 2017 has been added to the revised design plans. (see Sheet C-4). BETA2: Test pit information from 2012 and 2017 have been provided. No. 1 and No. 2 were performed on September 7, 2012 and TP-1 and TP-2 were performed on July 11, 2017. Existing elevations were not provided with No. 1 and No. 2 to determine elevation of seasonal high groundwater. TP-1 was performed at elevation 272 and bottom of test was at 262. Estimated seasonal high groundwater is elevation 266. TP-2 was performed at elevation 275 and bottom of test was at 267. No mottles were observed in this test pit and it is noted that the bottom of the proposed basin is elevation 265.3, below the bottom of the performed testing. MassDEP requires a minimum of 2 feet of separation between the bottom of an infiltration system and seasonal high groundwater – issue remains outstanding. JDMAII: Soil test data from testing conducted August 9, 2017 has been included in the revised designs. (see Sheet C4) BETA3: Test pit data provided issue resolved. SW12. Include provisions for protecting the infiltrative capacity of soils in infiltration areas during construction. Include the construction management area which is located on pervious pavement. JDMAI1: Construction equipment will be stored temporarily on paved surfaces. No soil stockpiles will be allowed in the area of the existing porous pavement surface. BETA2: Place note on plans specifying these provisions – issue remains outstanding. JDMAII: BETA3: Notes not shown on plans – issue remains outstanding. 80% TSS Removal (Standard Number 4): For new development, stormwater management systems must be designed to remove 80% of the annual load of Total Suspended Solids. Stormwater runoff from the proposed project area is intended to infiltrate into the proposed basin. TSS removal is to be achieved through the use of sediment forebay and infiltration basin. Long term pollution prevention measures have been included in the Operation and Maintenance Plan. SW13. Provide calculations to show the proposed sediment forebay has been sized to hold at a minimum, 0.1-inch/impervious acre. JDMAI1: Water Quality Calculations have been provided for 1/2 inch of runoff over the impervious area that runs to the existing basin. The area of the site being

Town of Hopkinton September 19, 2017 Page 8 of 9 redeveloped has an increase of 0.20 acres of impervious area which is entirely roof runoff, "clean runoff" according the Massachusetts Department of Environmental Protection (DEP) Stormwater Regulations. The remainder of the site is not being redeveloped and therefore is not included in this calculation. BETA2: Provide sediment forebay sizing calculations for the parking lot pavement areas – issue remains outstanding. JDMAII: BETA3: Forebay sizing calculations provided– issue resolved. Higher Potential Pollutant Loads (Standard Number 5): Stormwater discharges from Land Uses with Higher Potential Pollutant Loads require the use of specific stormwater management BMPs. This project documentation does not propose Land Uses with Higher Potential Pollutant Loads – not applicable. Critical Areas (Standard Number 6): Stormwater discharges to critical areas must utilize certain stormwater management BMPs approved for critical areas. This project does not discharge stormwater to critical areas – not applicable. Redevelopment (Standard Number 7): Redevelopment of previously developed sites must meet the Stormwater Management Standards to the maximum extent practicable. The site is considered new development because of the proposed new impervious areas associated with the building expansion. Construction Period Erosion and Sediment Controls (Standard Number 8): Erosion and sediment controls must be implemented to prevent impacts during construction or land disturbance activities. As shown, the project site is greater than 1 acre in area and land disturbance activities will require a Notice of Intent with EPA. A Stormwater Pollution Prevention Plan (SWPPP) is required to be submitted as part of MassDEP Stormwater Standards. Per the Town of Hopkinton Stormwater Regulations, an Erosion and Sediment Control Plan is required to be submitted. Plans include locations of erosion control barriers. SW14. Provide anticipated location(s) of soil/material stockpile area on plans and include erosion and sedimentation control measures to limit transport of materials. JDMAI1: An anticipated location for temporary soil stockpiling has been added to the revised design plans. (see sheet C-9) BETA2: Temporary soil stockpile area identified on plans – issue resolved. SW15. Site appears to disturb more than one acre of land. Provide figure and calculations if proposed work is not anticipated to disturb more than one acre. JDMAI1: Site redevelopment activities total less than 1 acre. BETA2: Provided project is not expanded further than shown, erosion and sediment control measures for the site are adequate – issue dismissed. SW16. Provide draft SWPPP / Erosion and Sediment Control Plan in accordance with requirements in Appendix C (1-5). JDMAI1: Site redevelopment activities total less than 1 acre. BETA2: Provided project is not expanded further than shown, erosion and sediment control measures for the site are adequate – issue dismissed. SW17. Provide catch basin inlet protection for existing catch basins on the site and include detail. BETA2: Detail provided – issue resolved. SW18. Recommend using stake compost filter sock or straw wattle in lieu of staked hay bales. BETA2: To reduce invasive species migration, recommend using compost filter sock or straw wattle – issue remains outstanding. BETA3: BETA defers to the Conservation Commission on this issue. Operations/maintenance plan (Standard Number 9): A long-Term Operation and Maintenance Plan shall be developed and implemented to ensure that stormwater management systems function as designed. Operation and Maintenance with basic tasks was included in the Stormwater Report and Drainage Calculations submission.

Town of Hopkinton September 19, 2017 Page 9 of 9 SW19. Provide and or update standalone Long Term Operation and Maintenance Plan which includes the requirements outlined in Appendix D 1-3. JDMAI1: An Operation and Maintenance Plan (O&M) and protocols are contained within the Stormwater Report. Prior to the completion of the site designs the O&M plan will separated out to function as a standalone document. BETA2: Include the following information as required in Appendix D 1-3 in the Operation and Maintenance Plan: provisions for the planning board to enter the property at reasonable times for inspection, signature of the owners – issue remains outstanding. JDMAII: BETA3: Provisions for the planning board to enter and signatures of owners not provided – recommend including these as conditions. SW20. Include map (preferably 11” x 17”) with the Long-Term Operation and Maintenance Plan (LTOMP) to identify and highlight BMP locations to be maintained and locations of snow storage. JDMAI1: An 11"x17" drainage plan has been provided and is attached to this letter. BETA2: Location of snow storage areas should be identified on plan – issue remains outstanding. BETA3: Issue not addressed – issue remains outstanding. SW21. Provide a description and delineation of public safety measures. JDMAI1: Access has been provided along the westerly property line to the basin and forebay. Construction materials will be organized and relocated if necessary to insure long term access for inspection and maintenance activities. BETA2: Safety measures not provided. Given the existing site features (dumpster area, plantings, basin) it is not clear how vehicles will access the basin. Provide figure showing proposed routes vehicle can take to the basin – issue remains outstanding. JDMAII: BETA3: with the expanded forebay, vehicles are less likely to be able to access stormwater basin from the east. Gate and plantings exist to the west of the dumpster area. Figure showing proposed routes a vehicle can take to access the basin not provided – issue remains outstanding. SW22. Provide and maintain vehicular access to stormwater basin for maintenance purposes. BETA2: See SW21. JDMAII: Access has been provided along the westerly property line to the basin and forebay. Construction materials will be organized and relocated if necessary to insure long term access for inspection and maintenance activities. BETA3: See SW21. Illicit Discharges (Standard Number 10): All illicit discharges to the stormwater management systems are prohibited. An Illicit Discharge Compliance Statement was not included with the submission. SW23. Provide a signed illicit discharge compliance statement. JDMAI1: A signed and sealed Illicit Discharge statement was included in the Stormwater Checklist section of the Stormwater Report. BETA2: Signed statement not included in submission – issue remains outstanding. BETA3: Signature provided – issue resolved. If we can be of any further assistance regarding this matter, please contact us at our office. Very truly yours, BETA Group, Inc.

Philip F Paradis, Jr., PE Associate

Christopher Luppino, PE Civil Engineer

O:\5700s\5700 - Hopkinton - Golden Pond Residential\Engineering\Reports\Golden Pond Residential Peer Review 9-14-17.docx

PUBLIC HEARING OUTLINE SOLAR SPECIAL PERMIT/STORMWATER MANAGEMENT PERMIT 147 LUMBER STREET An application for a solar special permit and a stormwater management permit application have both been filed for this address. The project proposes a 2.9 MW installation on approximately 11.4 acres of the total 41.5 acres. 1. 2. 3. 4. 5. 6. 7.

Principal Planner Overview of Site and Project Project introduction and review - Applicant Principal Planner Comments Consultant Review – BETA Group Other Town Departments Comments Add to Outline - Planning Board members and Public Detailed Discussion a. Site Layout b. Driveway Width c. Lighting d. Screening e. Array Size f. Underground Utilities g. Stormwater Management 8. Review by Other Boards a. Conservation Commission 9. Public comment/Discuss special permit/stormwater management standards and plan revisions to be made 10. Discuss conditions of approval with applicant 11. Public comment 12. Vote on Special Permit approval and conditions 13. Vote of Stormwater Management Permit 14. Close Public Hearing

APPLICATION FOR SPECIAL PERMIT

CEC Solar #1206, LLC 147 Lumber Street Hopkinton, Massachusetts

Prepared for: CEC Solar #1206, LLC c/o Clean Energy Collective 146 West Boylston Drive, 3rd Floor Worcester, MA, 01606

Presented by:

BEALS+THOMAS BEALS AND THOMAS, INC. Reservoir Corporate Center 144 Turnpike Road Southborough, MA 01772-2104

Submitted in Compliance with the Hopkinton Zoning Bylaws. August 24, 2017

283600PT001

BEALS+THOMAS BEALS AND THOMAS, INC. Reservoir Corporate Center 144 Turnpike Road Southborough, MA 01772-2104

T 508.366.0560 F 508.366.4391 www.bealsandthomas.com Regional Office: Plymouth, MA

August 24, 2017 Mr. John Ferrari, Chair Hopkinton Planning Board c/o Hopkinton Town Clerk 18 Main Street Hopkinton, Massachusetts

Via:

Hand Delivery

Reference:

Application for Special Permit Lumber Street Solar 147 Lumber Street Hopkinton, Massachusetts B+T Project No. 2836.00

Dear Chairperson Ferrari and Members of the Board: On behalf of the applicant, CEC Solar #1206, LLC, c/o Clean Energy Collective, Beals and Thomas, Inc. respectfully submits this application for Special Permit for the installation and operation of a Commercial Solar Photovoltaic Installation (Array) at 147 Lumber Street in Hopkinton, Massachusetts. This filing is submitted in accordance with the Hopkinton Zoning Bylaws (the Bylaws), specifically Article XXXI, Commercial Solar Photovoltaic Installations. The parcels on which the Array is proposed are R29-15-0 (147 Lumber Street) and R30-1-A (Off Alexander Street). The Project will consist of a 2.9 megawatt (MW) (DC) solar facility on an 11.4-acre site, composed of two parcels under common ownership totaling ±41.5 acres. The proposed development will connect to Lumber Street via an existing driveway, located at the western boundary of the Property, which will be extended to provide access to the Array. As required, enclosed are nine (9) total copies, including the original, of the Special Permit submission package as well as an electronic version of the submission on a flash drive. The following information is included for your review: Section 1.0: Section 2.0: Section 3.0: Section 4.0: Section 5.0:

Special Permit Forms; Project Narrative; Abutter Information; Stormwater Management Information; and Plans.

Mr. John Ferrari, Chair Hopkinton Planning Board August 24, 2017 Page 2

We understand that the Planning Board will provide newspaper notice of the public hearing regarding this Application, for which the Applicant will be billed directly. We understand that the Planning Board will send, via U.S. mail, notice to the abutters, with address labels, envelopes, and first-class postage provided by B+T. Enclosed is a check payable to the Town of Hopkinton in the amount of $2,000.00 for the appropriate application fee, which includes $500 for the Special Permit Application and $1,500 for the Consultant Review Fee. The Project has been designed in compliance with Article XXXI, Commercial Solar Photovoltaic Installation. We understand that specific items including the determination of an owner/installer, financial surety and liability insurance will be determined in coordination with the Town Planner upon a final contract with an owner/installer and will be conditioned as part of the approval. Thank you for your consideration of this Application. We look forward to meeting with the Planning Board at the next available public hearing. Should you have any questions regarding this Application or require additional information, please contact us at (508) 366-0560. Very truly yours, BEALS AND THOMAS, INC.

John P. Gelcich, AICP Senior Planner Enclosures cc:

Hopkinton Town Clerk (1 copy via hand delivery) Clean Energy Collective (1 copy via US Mail)

JPG/jyb/283600PT001

John E. Bensley, PE Principal

 

 

Questions  &  Answers  

   

Ground-­‐Mounted  Solar  Photovoltaic  Systems      

 

June  2015  

     

Westford  Solar  Park,  photo  courtesy  of  EEA  

Massachusetts  Department  of  Energy  Resources   Massachusetts  Department  of  Environmental  Protection   Massachusetts  Clean  Energy  Center  

  Table  of  Contents     Background……………………………………………………………………………………………………….3     Hazardous  Materials………………………………………………………………………………………...5       End-­‐of-­‐Life/Decommissioning…………………………………………………………………………..7       Ambient  Temperature  (“Heat  Island”)……………………………………………………………...9       Electric  and  Magnetic  Fields  (EMF)………………………………………………………………....10     Property  Values…………………………………………………………………………….……………..….13     Public  Safety  (including  fires)…………………………………………………………………………..14     Historic  Preservation……………………………………………………………………………………….16       Noise……………………………………………………………………………………………………………….18       Water-­‐Related  Impacts……………………………………………………………………………………20       Glare……………………………………………………………………………………………………………….22       Endangered  Species  and  Natural  Heritage………………………………………………………23  

2    

Background   Encouraging  increased  use  of  solar  photovoltaic  (PV)  technology,  which  converts  sunlight  directly  into   electricity,  is  a  key  priority  for  state  clean  energy  efforts.  The  environmental  benefits  of  solar  PV  abound.   Unlike  conventional  fossil  fuel  power  generation  (such  as  coal,  gas  and  oil),  generating  electricity  with   ground-­‐mounted  solar  PV  involves  no  moving  parts,  uses  no  water,  and  produces  no  direct  emissions  of   climate-­‐warming  greenhouse  gases.   Solar  PV  environmental  and  energy  benefits,  combined  with  strong  incentives  available  for  solar   projects,  have  significantly  increased  the  use  of  this  technology  recently.  The  Commonwealth’s  vibrant   solar  industry  has  a  variety  of  ownership  and  financing  options  for  Massachusetts  residents  and   businesses  looking  to  install  solar  PV  systems.  Purchasing  a  solar  PV  system  generally  involves  upfront   installation  and  equipment  costs,  but  there  are  significant  upfront  and  production-­‐based  incentives1.   As  the  Massachusetts  clean  energy  sector  grows,  the  Baker  Administration  is  working  to  ensure  that   solar  PV  and  other  clean  energy  technologies  are  sited  in  a  way  that  is  most  protective  of  human  health   and  the  environment,  and  minimizes  impacts  on  scenic,  natural,  and  historic  resources.     Purpose  of  Guide     This  guide  is  intended  to  help  local  decision-­‐makers  and  community  members  answer  common   questions  about  ground-­‐mounted  solar  PV  development.  Ground-­‐mounted  solar  PV  has  many  proven   advantages  and  there  has  been  a  steady  growth  of  well  received  projects  in  the  Commonwealth.     However,  these  systems  are  still  relatively  new  and  unfamiliar  additions  to  our  physical  landscape.     This  guide  focuses  on  questions  that  have  been  raised  concerning  the  installation  and  operation  of   ground-­‐mounted  solar  PV  projects.    It  provides  summaries  and  links  to  existing  research  and  studies  that   can  help  understand  solar  PV  technology  in  general  and  ground-­‐mounted  solar  in  particular.   Solar  PV  panels  can  and  are  of  course  also  installed  on  buildings2,  car  ports  or  light  poles.    This  guide   focuses  on  ground-­‐mounted  systems  since  most  questions  relate  to  this  type  of  solar  installation.   Developed  through  the  partnership  of  the  Massachusetts  Department  of  Energy  Resources  (DOER),  the   Massachusetts  Department  of  Environmental  Protection  (MassDEP),  and  the  Massachusetts  Clean   Energy  Center  (MassCEC),  this  guide  draws  from  existing  recent  literature  in  the  United  States  and   abroad  and  is  not  the  result  of  new  original  scientific  studies.  The  text  was  reviewed  by  the  National   Renewable  Energy  Laboratory  (NREL).   As  more  or  new  information  becomes  available,  the  guide  will  be  updated  and  expanded  accordingly.    

                                                                                                                        1

 For  a  comprehensive  overview,  start  at  http://masscec.com/index.cfm/page/Solar-­‐PV/pid/12584    For  an  overview  of  the  multiple  options  for  siting  PV  and  buildings  in  the  same  footprint,  see  the  Solar  Ready   Buildings  Planning  Guide,  NREL,  2009.   2

3    

Solar  PV  Projects  Are  Sited  Locally   The  siting  authority  for  solar  PV  projects  resides  at  the  local  -­‐  not  the  state  -­‐  level.  One  purpose  of  this   guide  is  to  inform  and  facilitate  local  efforts  to  expand  clean  energy  generation  in  a  sustainable  way,  and   provide  a  consolidated  source  of  existing  research  and  information  that  addresses  common  questions   faced  by  communities.   As  part  of  the  Green  Communities  Act  of  2008,  DOER  and  the  Massachusetts  Executive  Office  of  Energy   and  Environmental  Affairs  (EOEEA)  developed  a  model  zoning  by-­‐law/ordinance  called  “as-­‐of-­‐right   siting”  that  does  not  require  a  special  permit.    It  is  designed  to  help  communities  considering  adoption   of  zoning  for  siting  of  large-­‐scale  solar.  This  model  zoning  by-­‐law/ordinance  provides  standards  for  the   placement,  design,  construction,  operation,  monitoring,  modification  and  removal  of  new  large-­‐scale   ground-­‐mounted  solar  PV  installations.  The  latest  version  of  the  model  by-­‐law  was  published  in   December  20143.    It  provides  useful  information  that  will  not  be  repeated  extensively  in  this  guide.       Consider  Impacts  of  Other  Possible  Developments  at  Site   Use  of  land  for  the  purpose  of  solar  photovoltaic  power  generation  should  be  compatible  with  most   other  types  of  land  usage.    However,  DOER  strongly  discourages  designating  locations  that  require   significant  tree  cutting  because  of  the  important  water  management,  cooling  and  climate  benefits  trees   provide.    DOER  encourages  designating  locations  in  industrial  and  commercial  districts,  or  on  vacant,   disturbed  land.   When  assessing  the  impact  of  new  ground-­‐mounted  solar  arrays,  communities  and  other  stakeholders   should  carefully  consider  other  types  of  development  that  might  take  place  in  a  particular  location  if   there  was  no  solar  installation.    Stakeholders  should  bear  in  mind  the  higher  or  lower  impacts  that  those   alternatives  might  have  in  terms  of  noise,  air  pollution  or  landscape.    These  alternative  impacts  fall   outside  the  scope  of  this  guide,  but  are  relevant  when  looking  at  individual  projects.      

                                                                                                                        3

 http://www.mass.gov/eea/docs/doer/green-­‐communities/grant-­‐program/model-­‐solar-­‐zoning.pdf    

4    

Hazardous  Materials   The  Question:  What,  if  any,  health  risks  do  chemicals  used  to  manufacture  solar  panels  and  other   devices  used  in  solar  PV  arrays  pose  if  they  are  released  into  the  environment?     Bottom  Line:  Because  PV  panel  materials  are  enclosed,  and  don’t  mix  with  water  or  vaporize  into  the   air,  there  is  little,  if  any,  risk  of  chemical  releases  to  the  environment  during  normal  use.  The  most   common  type  of  PV  panel  is  made  of  tempered  glass,  which  is  quite  strong.    They  pass  hail  tests,  and  are   regularly  installed  in  Arctic  and  Antarctic  conditions.    Only  in  the  unlikely  event  of  a  sufficiently  hot  fire  is   there  a  slight  chance  that  chemicals  could  be  released.  This  is  unlikely  because  most  residential  fires  are   not  hot  enough  to  melt  PV  components  and  PV  systems  must  conform  to  state  and  federal  fire  safety,   electrical  and  building  codes.     Transformers  used  at  PV  installations,  that  are  similar  to  the  ones  used  throughout  the  electricity   distribution  system  in  cities  and  towns,  have  the  potential  to  release  chemicals  if  they  leak  or  catch  fire.   Transformer  coolants  containing  halogens  have  some  potential  for  toxic  releases  to  the  air  if  combusted.   However,  modern  transformers  typically  use  non-­‐toxic  coolants,  such  as  mineral  oils.  Potential  releases   from  transformers  using  these  coolants  at  PV  installations  are  not  expected  to  present  a  risk  to  human   health.     More  Information:    Ground-­‐mounted  PV  solar  arrays  are  typically  made  up  of  panels  of  silicon  solar  cells   covered  by  a  thin  layer  of  protective  glass,  which  is  attached  to  an  inert  solid  underlying  substance  (or   “substrate”).  While  the  vast  majority  of  PV  panels  currently  in  use  are  made  of  silicon,  certain  types  of   solar  cells  may  contain  cadmium  telluride  (CdTe),  copper  indium  diselenide  (CIS),  and  gallium  arsenide   (GaAs).   All  solar  panel  materials,  including  the  chemicals  noted  above,  are  contained  in  a  solid  matrix,  insoluble   and  non-­‐volatile  at  ambient  conditions,  and  enclosed.  Therefore,  releases  to  the  ground  from  leaching,   to  the  air  from  volatilization  during  use,  or  from  panel  breakage,  are  not  a  concern.  Particulate   emissions  could  only  occur  if  the  materials  were  ground  to  a  fine  dust,  but  there  is  no  realistic  scenario   for  this.  Panels  exposed  to  extremely  high  heat  could  emit  vapors  and  particulates  from  PV  panel   components  to  the  air.  However,  researchers  have  concluded  that  the  potential  for  emissions  derived   from  PV  components  during  typical  fires  is  limited  given  the  relatively  short-­‐duration  of  most  fires  and   the  high  melting  point  (>1000  degrees  Celsius)  of  PV  materials  compared  to  the  roof  level  temperatures   typically  observed  during  residential  fires  (800-­‐900  degrees  Celsius).  In  the  rare  instance  where  a  solar   panel  might  be  subject  to  higher  temperatures,  the  silicon  and  other  chemicals  that  comprise  the  solar   panel  would  likely  bind  to  the  glass  that  covers  the  PV  cells  and  be  retained  there.       Release  of  any  toxic  materials  from  solid  state  inverters  is  also  unlikely  provided  appropriate  electrical   and  installation  requirements  are  followed.    For  more  information  on  public  safety  and  fire,  see  the   Public  Safety  section  of  this  document.   We  should  also  note  that  usually  the  rain  is  sufficient  to  keep  the  panels  clean,  so  no  extra  cleaning  in   which  cleaning  products  might  be  used,  is  necessary.   5    

Resources:     Fthenakis,  V.M.,  Overview  of  Potential  Hazards  in  Practical  Handbook  of  Photovoltaics:  Fundamentals   and  Applications,  General  editors  T.  Markvart  and  L.  Castaner,  to  be  published  by  Elsevier  in  2003.       Fthenakis,  V.M.  Life  cycle  impact  analysis  of  cadmium  in  CdTe  PV  production.  Renewable  and   Sustainable  Energy  Reviews  8,  303-­‐334,  2004.   Fthenakis  V.M.,  Kim  H.C.,  Colli  A.,  and  Kirchsteiger  C.,  Evaluation  of  Risks  in  the  Life  Cycle  of   Photovoltaics  in  a  Comparative  Context,  21st  European  Photovoltaic  Solar  Energy  Conference,  Dresden,   Germany,  4-­‐8  September  2006.     Moskowitz  P.  and  Fthenakis  V.,  Toxic  materials  released  from  photovoltaic  modules  during  fires;  health   risks,  Solar  Cells,  29,  63-­‐71,  1990.   Sherwani,  A.F.,  Usmani,  J.A.,  &  Varun.  Life  cycle  assessment  of  solar  PV  based  electricity  generation   systems:  A  review.  Renewable  and  Sustainable  Energy  Reviews.  14,  540-­‐544,  2010.   Zayed,  J;  Philippe,  S  (2009-­‐08).  "Acute  Oral  and  Inhalation  Toxicities  in  Rats  With  Cadmium  Telluride"   (PDF).  International  journal  of  toxicology  (International  Journal  of  Toxicology)  28  (4):  259–65.   doi:10.1177/1091581809337630.  PMID  19636069. http://ijt.sagepub.com/cgi/content/short/28/4/259.  

6    

End-­‐of-­‐Life/Decommissioning   Question:  How  do  I  manage  solar  panels  after  they  are  decommissioned  and  no  longer  in  use?    Can  they   be  recycled  and  do  hazardous  waste  disposal  requirements  apply?   Bottom  Line:  As  more  solar  panels  are  decommissioned  interest  in  recycling  the  panels  has  increased  in   Europe  and  the  U.S.    Massachusetts  regulations  ensure  proper  disposal  and  recycling  of  panels  if  they   have  components  that  constitute  solid  or  hazardous  waste  under  state  regulations.   More  information:  The  average  life  of  solar  PV  panels  can  be  20-­‐30  years  (or  longer)  after  initial   installation.  PV  cells  typically  lose  about  0.5%  of  their  energy  production  capacity  per  year.  At  the  time   of  decommissioning,  panels  may  be  reused,  recycled  or  disposed.  Since  widespread  use  of  solar  PV  is   recent  in  Massachusetts,  only  a  small  percentage  of  solar  panels  in  use  in  the  state  have  had  to  be   replaced  due  to  damage  or  reached  the  end  of  their  useful  lifetime.  A  significant  increase  in  the  amount   of  end-­‐of-­‐life  PV  modules  is  expected  over  the  next  few  decades.   When  solar  panels  are  decommissioned  and  discarded,  state  rules  require  that  panel  disposal  be   “properly  managed”  pursuant  to  the  Massachusetts  hazardous  waste  regulations,  310  CMR  30.000.   There  are  many  different  types  of  solar  panels  used  in  ground-­‐mounted  or  roof  mounted  solar  PV   systems;  some  of  these  panels  have  components  that  may  require  special  hazardous  waste  disposal  or   recycling.  Solar  module  manufacturers  typically  provide  a  list  of  materials  used  in  the  manufacturing  of   their  product,  which  may  be  used  to  determine  the  proper  disposal  requirements  at  the  time  of   decommissioning.    Under  the  hazardous  waste  regulations,  the  burden  is  on  the  generator  of  the  panels   to  determine  if  the  waste  being  generated  (the  solar  panels)  is  hazardous  or  not.    This  determination  can   be  made  using  “knowledge”  (i.e.  an  MSDS  sheet  listing  the  materials  used  in  manufacture  of  the  panels)   or  testing  (i.e.  the  Toxicity  Characteristic  Leaching  Procedure  –  TCLP).       If  a  panel  is  tested  and  passes  TCLP  then  it  is  regulated  as  a  solid  waste;  if  it  fails  TCLP  then  it  is  regulated   as  a  hazardous  waste.   However,  if  the  solar  panel  is  determined  to  be  hazardous  due  solely  to  the  presence  of  metal-­‐bearing   circuit  boards,  the  panels  may  be  conditionally  exempt  from  the  hazardous  waste  regulations  if  destined   for  recycling.      See  310  CMR  30.202(5)(d)-­‐(e)  in  the  Mass.  Hazardous  Waste  Regulations.4   People  who  lease  land  for  solar  projects  are  encouraged  to  include  end-­‐of-­‐life  panel  management  as   part  of  the  lease.  In  cases  where  panels  are  purchased,  owners  need  to  determine  whether  the  end-­‐of                                                                                                                           4

 (5)  The  following  materials  are  not  subject  to  310  CMR  30.200,  or  any  other  provision  of  310   CMR  30.000:     (d)  Whole  used  circuit  boards  being  recycled  provided  they  are  free  of  mercury  switches,   mercury  relays,  nickel-­‐cadmium  batteries,  or  lithium  batteries.   (e)  Shredded  circuit  boards  being  recycled  provided  that  they  are:   1.  managed  in  containers  sufficient  to  prevent  a  release  to  the  environment  prior  to   recovery;  and,   2.  free  of  mercury  switches,  mercury  relays  and  nickel-­‐cadmium  batteries  and  lithium   batteries.    

7    

life  panels  are  a  solid  or  hazardous  waste  and  dispose  or  recycle  the  panels  appropriately.     Massachusetts  regulations  require  testing  of  waste  before  disposal.     Because  of  the  various  materials  used  to  produce  solar  panels  (such  as  metal  and  glass),  interest  in   recycling  of  solar  modules  has  grown.  Throughout  Europe,  a  not-­‐for-­‐profit  association  (PV  Cycle)  is   managing  a  voluntary  collection  and  recycling  program  for  end-­‐of-­‐life  PV  modules.  The  American   photovoltaic  industry  is  not  required  by  state  or  federal  regulation  to  recycle  its  products,  but  several   solar  companies  are  starting  to  recycle  on  a  voluntary  basis.  Some  manufacturers  are  offering  end-­‐of-­‐life   recycling  options  and  independent  companies  looking  to  recycle  solar  modules  are  growing.  This  allows   for  the  recycling  of  the  PV  panels  and  prevents  issues  with  the  hazardous  materials.  Currently,  the   California  Department  of  Toxic  Substances  Control  is  considering  standards  for  the  management  of  solar   PV  panels  at  the  end  of  their  use.   DOER’s  model  zoning  provides  language  on  requirements  for  abandonment  and  decommissioning  of   solar  panels  for  use  by  local  officials  considering  local  approvals  for  these  projects.   Resources     End-­‐of-­‐life  PV:  then  what?  -­‐  Recycling  solar  PV  panels   http://www.renewableenergyfocus.com/view/3005/end-­‐of-­‐life-­‐pv-­‐then-­‐what-­‐recycling-­‐solar-­‐pv-­‐panels/     MassDEP  Hazardous  Waste  Regulations  310  CMR  30.000   http://www.mass.gov/eea/agencies/massdep/recycle/regulations/310-­‐cmr-­‐30-­‐000.html     PV  Cycle,  Europe:  http://www.pvcycle.org/     California  Department  of  Toxic  Substances  Control,  Proposed  Standards  for  the  Management  of   Hazardous  Waste  Solar  Modules,   http://www.dtsc.ca.gov/LawsRegsPolicies/Regs/Reg_Exempt_HW_Solar_Panels.cfm    

 

8    

Ambient  Temperature  (“Heat  Island”)     The  Question:  Does  the  presence  of  ground-­‐mounted  solar  PV  arrays  cause  higher  ambient   temperatures  in  the  surrounding  neighborhood  (i.e.,  the  “heat  island”  effect)?   Bottom  Line:  All  available  evidence  indicates  that  there  is  no  solar  “heat  island”  effect  caused  by  the   functioning  of  solar  arrays.  Cutting  shade  trees  for  solar  PV  might  increase  the  need  for  cooling  if  those   trees  were  shading  buildings.  This  is  primarily  a  concern  in  town  centers  and  residential  areas  (locations   where  large  ground-­‐mounted  PV  is  not  encouraged)  and  is  a  potential  impact  of  any  development   activity  that  requires  tree-­‐cutting.   More  Information:    All  available  evidence  indicates  that  there  is  no  solar  “heat  island”  effect  caused  by   the  functioning  of  solar  arrays.    Solar  panels  absorb  photons  from  direct  sunlight  and  convert  it  to   electricity.  This  minimizes  the  likelihood  of  substantially  changing  temperatures  at  the  site  or  the   surrounding  neighborhood.  For  an  area  with  no  PV  system,  solar  energy  impacting  the  ground  is  either   reflected  or  absorbed.  There  is  no  research  to  support  heat  production  from  the  solar  panels   themselves.   Sunpower,  a  private  solar  manufacturer,  conducted  a  study  on  the  impact  of  solar  PV  on  the  local   temperature,  and  concluded  that  a  solar  PV  array  can  absorb  a  higher  percentage  of  heat  than  a   forested  parcel  of  land  without  an  array.  The  study  points  out  that  while  solar  PV  modules  can  reach   high  operating  temperatures  up  to  120  degrees  Fahrenheit,  they  are  thin  and  lightweight  and  therefore   do  not  store  a  large  amount  of  heat.  Because  of  this,  and  the  fact  that  panels  are  also  shown  to  cool  to   ambient  air  temperature  shortly  after  the  sun  sets,  the  Sunpower  study  concludes  that  the  area   surrounding  a  large-­‐scale  solar  array  is  unlikely  to  experience  a  net  heating  change  from  the  panels.   If  trees  are  removed  that  were  previously  shading  a  building,  that  building  could  get  warmer  in  full   sunshine  than  when  the  trees  were  shading  it.    The  June  1,  2011  tornado  that  ripped  through  Western   Massachusetts  created  an  opportunity  to  empirically  measure  the  effects  of  the  loss  of  neighborhood   trees  on  temperatures  and  air  humidity  in  the  streets.  A  report  by  the  U.S.  Department  of  Agriculture   Forest  Service  concluded  that  daily  mean  morning  and  afternoon  temperatures  were  typically  greater  in   the  tornado-­‐impacted  neighborhood  in  Springfield,  Massachusetts  than  in  the  unaffected  neighborhood   and  forest  sites,  but  were  similar  at  night.  Residents  noted  increased  use  of  air-­‐conditioning  units  and  an   overall  increase  in  energy  costs  in  July  and  August  of  2011.   Resources:   SUNPOWER,  Impact  of  PV  Systems  on  Local  Temperature,  July  2010   USDA  Forest  Services  report:  http://www.regreenspringfield.com/wp-­‐ content/uploads/2011/11/tornado%20climate%20report%203.pdf      

9    

Electric  and  Magnetic  Fields  (EMF)   The  Question:    What,  if  any,  health  risks  do  the  electric  and  magnetic  fields  (EMF)  from  solar  panels  and   other  components  of  solar  PV  arrays  pose?   Bottom  Line:  Electric  and  magnetic  fields  are  a  normal  part  of  life  in  the  modern  world.  PV  arrays   generate  EMF  in  the  same  extremely  low  frequency  (ELF)  range  as  electrical  appliances  and  wiring  found   in  most  homes  and  buildings.  The  average  daily  background  exposure  to  magnetic  fields  is  estimated  to   be  around  one  mG  (milligauss  –  the  unit  used  to  measure  magnetic  field  strength),  but  can  vary   considerably  depending  on  a  person’s  exposure  to  EMF  from  household  electrical  devices  and  wiring.   The  lowest  exposure  level  that  has  been  potentially  associated  with  a  health  effect  is  three  mG.       Measurements  at  three  commercial  PV  arrays  in  Massachusetts  demonstrated  that  their  contributions   to  off-­‐site  EMF  exposures  were  low  (less  than  0.5  mG  at  the  site  boundary),  which  is  consistent  with  the   drop  off  of  EMF  strength  based  on  distance  from  the  source.       More  Information:    Solar  PV  panels,  inverters  and  other  components  that  make  up  solar  PV  arrays   produce  extremely  low  frequency  EMF  when  generating  and  transmitting  electricity.  The  extremely  low   frequency  EMF  from  PV  arrays  is  the  same  as  the  EMF  people  are  exposed  to  from  household  electrical   appliances,  wiring  in  buildings,  and  power  transmission  lines  (all  at  the  power  frequency  of  60  hertz).   EMF  produced  by  cell  phones,  radios  and  microwaves  is  at  much  higher  frequencies  (30,000  hertz  and   above).   Electric  fields  are  present  when  a  device  is  connected  to  a  power  source,  but  are  shielded  or  blocked  by   common  materials,  resulting  in  low  potential  for  exposures.  On  the  other  hand,  magnetic  fields,  which   are  only  generated  when  a  device  is  turned  on,  are  not  easily  shielded  and  pass  through  most  objects,   resulting  in  greater  potential  for  exposure.  Both  types  of  fields  are  strongest  at  the  source  and  their   strength  decreases  rapidly  as  the  distance  from  the  source  increases.  For  example,  the  magnetic  field   from  a  vacuum  cleaner  six  inches  away  from  the  motor  is  300  mG  and  decreases  to  two  mG  three  feet   away.  People  are  exposed  to  EMF  during  normal  use  of  electricity  and  exposure  varies  greatly  over  time,   depending  on  the  distance  to  various  household  appliances  and  the  length  of  time  they  are  on.  The  daily   average  background  level  of  magnetic  fields  for  US  residents  is  one  mG.   EMF  from  PV  Arrays:  Solar  PV  panels  produce  low  levels  of  extremely  low  frequency  (ELF)  EMF,  with   measured  field  strengths  of  less  than  one  mG  three  inches  from  the  panel.  Solar  PV  power  inverters,   transformers  and  conduits  generate  higher  levels  of  ELF-­‐EMF.  The  amount  of  ELF-­‐EMF  is  proportional  to   the  electrical  capacity  of  the  inverter  and  is  greater  when  more  current  (electricity)  is  flowing  through  a   power  line.       In  a  study  of  two  PV  arrays  (using  10-­‐20  kW  invertors)  in  Kerman  and  Davis,  California,  the  magnetic  field   was  highest  at  the  inverters  and  transformers,  but  decreased  rapidly  to  less  than  one  mG  within  50  feet   of  the  units,  well  within  the  boundary  of  the  PV  array  (Chang  and  Jennings  1994).  This  data  indicates   that  extremely  low  frequency  EMF  field  strengths  at  residences  near  systems  of  this  size  would  be  below   the  typical  levels  experienced  by  most  people  at  home.  The  highest  extremely  low  frequency  EMF  (up  to   1,050  mG)  was  found  next  to  an  inverter  unit  at  the  point  of  entry  of  the  electrical  conduits.  Even  this   10    

value  is  less  than  the  extremely  low  frequency  EMF  reported  for  some  common  household  devices  such   as  an  electric  can  opener  with  a  maximum  of  1500  mG  at  6  inches.       In  a  recent  study  of  three  ground  mounted  PV  arrays  in  Massachusetts,  the  above  results  were   confirmed.    The  PV  arrays  had  a  capacity  range  of  1  to  3.5  MW.    Magnetic  field  levels  along  the  PV  array   site  boundary  were  in  the  very  low  range  of  0.2  to  0.4  mG.    Magnetic  fields  at  3  to  7  feet  from  the   inverters  ranged  from  500  to  150  mG.    At  a  distance  of  150  feet  from  the  inverters,  these  fields  dropped   back  to  very  low  levels  of  0.5  mG  or  less,  and  in  many  cases  to  much  less  than  background  levels  (0.2   mG).   Potential  Health  Effects:    Four  research  studies  have  reported  an  association  between  three  to  four  mG   EMF  exposure  and  childhood  leukemia,  while  11  other  studies  have  not.  These  studies  are  inconsistent   and  do  not  demonstrate  a  causal  link  that  would  trigger  a  World  Health  Organization  (WHO)  designation   of  EMF  as  a  possible  carcinogen5.  Studies  looking  at  other  cancers  in  humans  and  animals  have  not   found  evidence  of  a  link  to  residential  ELF-­‐EMF  exposure.       Reference  Exposure  Levels:  To  protect  the  general  public  from  health  effects  from  short-­‐term  high  level   magnetic  fields,  the  International  Commission  on  Non-­‐Ionizing  Radiation  Protection  (ICNIRP,  2010)   advised  an  exposure  limit  for  extremely  low  frequency  magnetic  fields  at  2000  mG.  ICNIRP  determined   that  the  evidence  on  the  impact  of  long-­‐term  exposure  to  low  level  magnetic  fields  was  too  uncertain  to   use  to  set  a  guideline.  Guidelines  for  the  magnetic  field  allowed  at  the  edge  of  transmission  line  right-­‐of-­‐ ways  have  been  set  at  200  mG  by  Florida  and  New  York.  Exposure  to  magnetic  fields  greater  than  1000   mG  is  not  recommended  for  people  with  pacemakers  or  defibrillators  (ACGIH,  2001).     Resources:   American  Conference  of  Government  Industrial  Hygienist  (ACGIH).  2001.  as  cited  in  NIEHS  2002.   Chang,  GJ  and  Jennings,  C.  1994.  Magnetic  field  survey  at  PG&E  photovoltaic  sites.  PG&E  R&D  Report   007.5-­‐94-­‐6.       Electric  Power  Research  Institute  (EPRI).  2012.  EMF  and  your  health.   http://my.epri.com/portal/server.pt?Abstract_id=000000000001023105.     International  Commission  on  Non-­‐Ionizing  Radiation  Protection  (ICNIRP).  2010.  ICNIRP  Guidelines  for   limiting  exposure  to  time-­‐varying  electric  and  magnetic  fields  (1  Hz  –  100kHz).  Health  Physics  99(6):818-­‐ 836.   National  Cancer  Institute  (NCI).  2005.  Magnetic  Field  Exposure  and  Cancer:  Questions  and  Answers.    U.S.   Department  of  Health  and  Human  Services,  National  Institutes  of  Health.  Available   http://www.cancer.gov/cancertopics/factsheet/Risk/magnetic-­‐fields,  accessed  May  14,  2012.                                                                                                                           5

 WHO  has  designated  ELF-­‐EMF  as  a  possible  carcinogen.  The  use  of  the  label  “possible  carcinogen”  indicates  that   there  is  not  enough  evidence  to  designate  ELF-­‐EMF  as  a  “probable  carcinogen  “or  “human  carcinogen,”  the  two   indicators  of  higher  potential  for  being  carcinogenic  in  humans.    

11    

National  Institute  of  Environmental  Health  Science  (NIEHS)  2002.  Electric  and  Magnetic  Fields  Associated   with  the  Use  of  Electric  Power:  Questions  and  Answers.  Available   http://www.niehs.nih.gov/health/assets/docs_p_z/results_of_emf_research_emf_questions_answers_b ooklet.pdf,  accessed  May  11,  2012.   National  Institute  of  Environmental  Health  Science  (NIEHS)  web  page  on  EMF.  Available   http://www.niehs.nih.gov/health/topics/agents/emf/,  accessed  May  11,  2012.   Oregon  Department  of  Transportation  (Oregon  DOT).  Scaling  public  concerns  of  electromagnetic  fields   produced  by  solar  photovoltaic  arrays.  Produced  by  Good  Company  for  ODOT  for  the  West  Linn  Solar   Highway  Project.  Available  www.oregon.gov/ODOT/HWY/OIPP/docs/emfconcerns.pdf.   World  Health  Organization  (WHO).  2007.  Electromagnetic  fields  and  public  health:  Exposure  to   extremely  low  frequency  fields.  Fact  sheet  N°322.  June  2007.  Available   http://www.who.int/mediacentre/factsheets/fs322/en/index.html,  accessed  May  16,  2012.  This  fact   sheet  provides  a  short  summary  of  the  in-­‐depth  review  documented  in  the  WHO  2007,  Environmental   Health  Criteria  238.  Available  http://www.who.int/peh-­‐emf/publications/elf_ehc/en/index.html.  

12    

Property  Values   Question:  How  do  ground-­‐mounted  solar  PV  arrays  adjacent  to  residential  neighborhoods  influence  the   property  values  in  those  neighborhoods?   Bottom  Line:  No  research  was  found  specific  to  ground-­‐mounted  solar  PV  and  property  values.     Residential  property  value  research  on  roof-­‐mounted  solar  PV  and  wind  turbines  illustrates  no  evidence   of  devaluation  of  homes  in  the  area.  Municipalities  that  adopt  zoning  for  solar  facilities  may  want  to   consider  encouraging  project  developers  to  include  screening  vegetation  along  site  borders  to  minimize   visual  impacts  on  surrounding  neighborhoods.   More  Information:  A  review  of  literature  nationwide  shows  little  evidence  that  solar  arrays  influence   nearby  property  values.  An  analysis  focused  on  roof-­‐mounted  solar  PV  done  by  the  U.S.  Department  of   Energy  Lawrence  Berkeley  National  Laboratory  concludes  that  household  solar  installation  actually   increases  home  property  values.  This  research  analyzes  a  large  dataset  of  California  homes  that  sold   from  2000  through  mid-­‐2009  with  PV  installed.  Across  a  large  number  of  repeat  sales  model   specifications  and  robustness  tests,  the  analysis  finds  strong  evidence  that  California  homes  with  PV   systems  have  sold  for  a  premium  over  comparable  homes  without  PV  systems.     Resources:   An  Analysis  of  the  Effects  of  Residential  Photovoltaic  Energy  Systems  on  Home  Sales  Prices  in  California   http://emp.lbl.gov/sites/all/files/lbnl-­‐4476e.pdf      

 

13    

Public  Safety  (including  fires)   Question:  What  public  safety  issues  arise  from  people’s  (including  children)  access  to  areas  where  solar   arrays  are  installed?    Can  electrical  and  other  equipment  associated  with  solar  projects  cause  electrical   fires?   Bottom  Line:  Large-­‐scale  ground-­‐mounted  arrays  are  typically  enclosed  by  fencing.  This  prevents   children  and  the  general  public  from  coming  into  contact  with  the  installations,  thus  preventing  unsafe   situations.  The  National  Electric  Code  has  mandatory  requirements  to  promote  the  electrical  safety  of   solar  PV  arrays.  Emergency  personnel  responding  to  potential  emergencies  at  a  solar  PV  site  face  the   most  risk,  but  the  solar  industry  and  firefighters  provide  training  and  education  for  emergency   personnel  to  ensure  that  the  proper  safety  precautions  are  taken.       More  Information:  The  National  Electric  Code  has  mandatory  requirements  for  the  electrical  safety  of   solar  PV  arrays.    To  protect  against  intruders,  Article  690  of  the  National  Electric  Code  covers  the  safety   standards  for  solar  PV  installation  and  requires  that  conductors  installed  as  part  of  solar  PV  be  “not   readily  accessible”.  With  a  large-­‐scale  ground-­‐mounted  array,  a  fence  is  typically  installed  around  the   system  to  prevent  intruders.  Some  communities  have  solar  PV  or  signage  by-­‐laws  that  require   identification  of  the  system  owner  and  24-­‐hour  emergency  contact  information.     DOER’s  Model  by-­‐Law/ordinance  requires  owners  of  solar  PV  facilities  to  provide  a  copy  of  the  project   summary,  electrical  schematic,  and  site  plan  to  the  local  fire  chief,  who  can  then  work  with  the  owner   and  local  emergency  services  to  develop  an  emergency  response  plan.   These  measures  can  be  combined  with  products  to  prevent  theft  of  the  panels.    Some  are  very  low  cost   options  (fastener  type)  while  there  are  other  options  that  are  more  expensive  (alarm  system  type)  but   also  more  effective.    The  biggest  potential  risk  associated  with  solar  PV  systems  is  the  risk  of  shock  or   electrocution  for  firefighters  and  other  emergency  responders  who  could  come  in  contact  with  high   voltage  conductors.    A  2010  study  on  firefighter  safety  and  emergency  response  for  solar  PV  systems  by   the  Fire  Protection  Research  Foundation,  based  in  Quincy,  Massachusetts,  recommended  steps   firefighters  can  take  when  dealing  with  wiring  and  other  components  that  may  be  energized.    The  Solar   Energy  Business  Association  of  New  England  (SEBANE)  has  been  working  to  provide  training  and   education  to  first-­‐responders  to  identify  and  avoid  potential  hazards  when  responding  to  a  solar  PV  fire.       For  more  information  about  toxics/fires,  see  the  Hazardous  Materials  Section.   Resources:   Moskowitz,  P.D.  and  Fthenakis,  V.M.,  Toxic  Materials  Released  from  Photovoltaic  Modules  During  Fires:   Health  Risks,  Solar  Cells,  29,  63-­‐71,  1990.  21.       Solar  America  Board  for  Codes  and  Standards   http://www.solarabcs.org/about/publications/reports/blindspot/pdfs/BlindSpot.pdf     Fire  Fighter  Safety  and  Emergency  Response  for  Solar  Power  Systems:  Final  Report,  May  2010.    Prepared   by  The  Fire  Protection  Research  Foundation   14    

  National  Electric  Code  Article  250:  Grounding  and  Bonding,  Article  300:  Wiring  Methods,  Article  690   Solar  PV  Systems,  Article  705  Interconnected  Electric  Power  Production  Sources      

15    

Historic  Preservation   The  Question:    What  are  the  appropriate  standards  when  land  with  historical  or  archaeological   significance  is  developed  for  large-­‐scale  solar  PV  arrays?   Bottom  Line:  Parties  undertaking  solar  PV  projects  with  state  or  federal  agency  involvement  must   provide  the  Massachusetts  Historical  Commission  (MHC)  with  complete  project  information  as  early  as   possible  in  the  planning  stage,  by  mail  to  the  MHC’s  office  (see  Resources).  Parties  should  also  contact   local  planning,  historical  or  historic  district  commissions  to  learn  about  any  required  local  approvals.     Municipalities  should  also  take  the  presence  of  historic  resources  into  account  when  establishing  zoning   regulations  for  solar  energy  facilities  in  order  to  avoid  or  minimize  impacts.   More  Information:  Land  being  evaluated  for  the  siting  of  large-­‐scale  solar  PV  has  historical  or   archaeological  significance  including  properties  listed  in  the  National  or  State  Registers  of  Historic  Places   and/or  the  Inventory  of  Historic  and  Archaeological  Assets  of  the  Commonwealth.       Federal  and  state  laws  require  that  any  new  construction,  demolition  or  rehabilitation  projects   (including  new  construction  of  solar  PV)  that  propose  to  use  funding,  licenses  or  permits  from  federal  or   state  government  agencies  must  be  reviewed  by  the  MHC  so  that  feasible  alternatives  are  developed   and  implemented  to  avoid  or  mitigate  any  adverse  effects  to  historic  and  archaeological  properties.   Projects  receiving  federal  funding,  licenses  or  permits  are  reviewed  by  the  involved  federal  agency  in   consultation  with  the  MHC  and  other  parties  in  compliance  with  Section  106  of  the  National  Historic   Preservation  Act  of  1966  (16  U.S.C.  470f)  and  the  implementing  regulations  (36  CFR  800)  in  order  to   reach  agreement  to  resolve  any  adverse  effects.  Projects  receiving  state  funding,  licenses  or  permits   must  notify  the  MHC  in  compliance  with  M.G.L.  c.  9,  ss.  26-­‐27C  and  the  implementing  regulations  950   CMR  71.  If  the  MHC  determines  that  the  project  will  have  an  adverse  effect,  the  involved  state  agency,   the  project  proponent,  the  local  historical  preservation  agencies,  and  other  interested  parties  consult  to   reach  an  agreement  that  outlines  measures  to  be  implemented  to  avoid,  minimize,  or  mitigate  adverse   effects.  For  projects  with  both  federal  and  state  agency  involvement,  the  Section  106  process  is  used.     Some  communities  have  local  preservation  ordinances  or  established  local  historic  districts  that  require   local  approval  for  new  construction  visible  from  a  public  way.  Local  historic  district  commissions  have   adopted  design  guidelines  for  new  construction  within  their  historic  districts  and  historic   neighborhoods.    However,  these  guidelines  must  account  for  Chapter  40C  Section  7  of  the  General  Laws,   which  requires  a  historic  district  commission  to  consider  the  policy  of  the  Commonwealth  to  encourage   the  use  of  solar  energy  systems  and  to  protect  solar  access.   Resources:   Federal  Agency  Assisted  Projects:   Section  106  review  information  and  the  federal  regulations  36  CFR  800  are  available  at  the  Advisory   Council  on  Historic  Preservation  (ACHP)  web  site:  www.achp.gov.  Check  with  the  involved  federal   agency  for  how  they  propose  to  initiate  the  MHC  notification  required  by  36  CFR  800.3.     State  Agency  Assisted  Projects:   16    

Massachusetts  General  Laws  Chapter  9,  sections  26-­‐27C   MHC  Regulations  950  CMR  71  (available  from  the  State  House  Bookstore)       MHC  Review  &  Compliance  FAQs  http://www.sec.state.ma.us/mhc/mhcrevcom/revcomidx.htm   MHC  Project  Notification  Form  (PNF)  &  Guidance  for  Completing  the  PNF  and  required  attachments   (USGS  locus  map,  project  plans,  current  photographs  keyed  to  the  plan).  Mail  or  deliver  the  complete   project  information  to  the  MHC’s  office:    http://www.sec.state.ma.us/mhc/mhcform/formidx.htm   General  Guidance  about  Designing  Solar  PV  Projects  on  Historic  Buildings  and  in  Historic  Areas:   http://www.nrel.gov/docs/fy11osti/51297.pdf    

 

 

17    

Noise   Question:  Do  the  inverters,  transformers  or  other  equipment  used  as  part  of  ground-­‐mounted  solar  PV   create  noise  that  will  impact  the  surrounding  neighborhood?   Bottom  Line:  Ground-­‐mounted  solar  PV  array  inverters  and  transformers  make  a  humming  noise  during   daytime,  when  the  array  generates  electricity.    At  50  to  150  feet  from  the  boundary  of  the  arrays,  any   sound  from  the  inverters  is  inaudible.    Parties  that  are  planning  and  designing  ground-­‐mounted  solar  PV   should  explore  options  to  minimize  noise  impacts  to  surrounding  areas.  This  could  include  conducting   pre-­‐construction  sound  studies,  evaluating  where  to  place  transformers,  and  undertaking  appropriate   noise  mitigation  measures.       More  Information:  Most  typically,  the  source  of  noise  associated  with  ground-­‐mounted  solar  PV  comes   from  inverters  and  transformers.  There  also  may  be  some  minimal  noise  from  switching  gear  associated   with  power  substations.    The  crackling  or  hissing  sound  caused  by  high-­‐voltage  transmission  lines  (the   “Corona  Effect”)  is  not  a  concern  in  the  case  of  solar  PV,  which  uses  lower  voltage  lines.   Parties  siting  ground-­‐mounted  solar  PV  projects  should  consult  equipment  manufacturers  to  obtain   information  about  sound  that  can  be  expected  from  electrical  equipment,  since  this  can  vary.  For   example,  according  to  manufacturer’s  information,  a  SatCon  Powergate  Plus  1  MW  Commercial  Solar  PV   Inverter  has  an  unshielded  noise  rating  of  65  decibels  (dBA)  at  five  feet.  This  is  approximately  the  sound   equivalent  of  having  a  normal  conversation  with  someone  three  feet  away.  Another  source  of   information  is  the  National  Electrical  Manufacturers  Association  (NEMA)  standards,  which  will  provide   maximum  sound  levels  from  various  equipment  arrays.    From  NEMA,  a  large  dry-­‐type  transformer   (2001-­‐3333  kVA)  that  is  forced  air  cooled  and  ventilated  has  an  average  sound  level  of  71  dBA,  which  is   approximately  the  sound  level  one  would  expect  from  a  vacuum  cleaner  at  ten  feet.  There  may  be   several  such  units  on  a  substantially  sized  PV  site,  which  would  increase  the  sound  level  to  some  degree.     Sound  impacts  from  electrical  equipment  can  be  modeled  to  the  property  line  or  nearest  sensitive   receptor  (residence).  Sound  impacts  can  be  mitigated  with  the  use  of  enclosures,  shielding  and  careful   placement  of  the  sound-­‐generating  equipment  on-­‐site.  The  rule  of  thumb  for  siting  noise-­‐generating   equipment  is  that  the  sound  impact  can  be  reduced  by  half  by  doubling  the  distance  to  the  receptor.   In  some  areas  both  in  the  US  and  Canada,  sound  impact  analysis  is  required  as  part  of  the  permitting   process  for  large  PV  systems.  For  example,  in  the  Province  of  Ontario,  Canada,  any  project  greater  than   12  MW  is  required  to  perform  a  sound  impact  analysis  (Ontario  359/09).  California  also  requires  a  sound   impact  analysis  for  large  PV  projects.  Massachusetts  currently  has  no  such  requirement,  but  the  reader   should  note  that  ground-­‐mounted  systems  in  Massachusetts  very  rarely  go  over  6  MW,  which  is  half  the   size  of  the  12  MW  that  triggers  a  sound  analysis  in  Ontario.   A  recent  study  measured  noise  levels  at  set  distances  from  the  inverters  and  from  the  outer  boundary  of   three  ground-­‐mounted  PV  arrays  in  Massachusetts  with  a  capacity  range  of  1  to  3.5  MW.    Close  to  the   inverters  (10  feet),  sound  levels  varied  from  an  average  of  55  dBA  to  65  dBA.    Sound  levels  along  the   fenced  boundary  of  the  PV  arrays  were  generally  at  background  levels,  though  a  faint  inverter  hum   could  be  heard  at  some  locations.    Any  sound  from  the  PV  array  and  equipment  was  inaudible  and   18    

sound  levels  were  at  background  levels  at  setback  distances  of  50  to  150  feet  from  the  boundary.     Project  developers  should  consult  with  local  planning  and  zoning  officials  to  determine  if  local  noise   ordinances  may  be  applicable.  Many  local  noise  ordinances  establish  absolute  limits  on  project  impact   noise  (such  as  a  40  dBA  nighttime  limit).  In  these  communities,  a  noise  impact  assessment  may  be   required.     Resources:       NEMA  Standards  Publication  No.  TR=1-­‐1993(R2000),  Transformers,  Regulators  and  Reactors   Noise  Assessment:  Borrego  1  Solar  Project,  MUP  3300-­‐10-­‐26  Prepared  by  Ldn  Consulting,  Inc,  Fallbrook,   CA.  January  14,  2011   Ontario  Regulation  359/09  Renewable  Energy  Approval  (REA)  Regulation,  Ontario  Ministry  of  the   Environment,  Canada  http://www.ontario.ca/environment-­‐and-­‐energy/renewable-­‐energy-­‐approvals   Tech  Environmental,  Study  of  Acoustic  and  EMF  levels  from  Solar  Photovoltaic  Projects,  Prepared  for  the   Massachusetts  Clean  Energy  Center,  December  2012,   http://images.masscec.com/uploads/attachments/Create%20Basic%20page/Study_of_Acoustic_and_E MF_Levels_from_Solar_Photovoltaic_Projects.pdf      

19    

Water-­‐Related  Impacts     Question:  Can  chemicals  that  might  be  contained  in  solar  PV  threaten  public  drinking  water  systems?     Will  flooding  occur  in  cases  where  trees  must  be  removed  in  order  to  install  the  solar  arrays?  How  do  we   ensure  that  wetland  resources  are  protected?   Bottom  Line:  Rules  are  in  place  to  ensure  that  ground-­‐mounted  solar  arrays  are  installed  in  a  ways  that   protect  public  water  supplies,  wetlands,  and  other  water  resource  areas.    All  solar  panels  are  contained   in  a  solid  matrix,  are  insoluble  and  are  enclosed.    Therefore,  releases  are  not  a  concern.   More  Information:    Because  trees  offer  multiple  water  management,  cooling  and  climate  benefits,   clear-­‐cutting  of  trees  for  the  installation  of  ground-­‐mounted  solar  PV  is  discouraged.  For  projects  that  do   propose  to  alter  trees,  the  Massachusetts  Environmental  Policy  Act  (MEPA)  has  thresholds  for  the   proposed  alteration  of  a  certain  number  of  acres  of  land,  the  size  of  electrical  facilities,  and  other  criteria   that  trigger  state  review  of  proposed  projects.    Clear  cutting  of  trees  and  other  aspects  of  proposed   projects  would  be  reviewed  through  an  Environmental  Notification  Form/Environmental  Impact   Statement  if  thresholds  are  triggered.  More  information  is  available  at:     MassDEP  has  determined  that  the  installation  of  solar  arrays  can  be  compatible  with  the  operation  and   protection  of  public  drinking  water  systems.  This  includes  the  installation  of  solar  arrays  within  the  Zone   I,  which  is  a  400-­‐foot  protective  radius  around  a  public  ground  water  well.  Solar  projects  proposed  on   lands  owned  by  public  water  systems  outside  the  Zone  I  may  be  approved  subject  to  standard  best   management  practices,  such  as  the  proper  labeling,  storage,  use,  and  disposal  of  products.  MassDEP  has   a  guidance/review  process  in  place  to  ensure  that  the  installation  of  ground-­‐mounted  solar  PV  in  these   areas  protects  public  water  supplies.   Installing  solar  arrays  on  undeveloped  land  can  preserve  the  permeable  nature  of  the  land  surface   provided  the  project  design  minimizes  disturbance  to  natural  vegetative  cover,  avoids  concentrated   runoff,  and  precipitation  is  otherwise  recharged  into  the  ground  to  the  greatest  extent  practicable.     Storm  water  flow,  as  well  as  information  about  site-­‐specific  soils  and  slope,  is  taken  into  account  during   the  design  and  installation  of  solar  arrays.           MassDEP  discourages  installation  of  ground-­‐mounted  solar  PV  systems  in  wetland  areas,  including   riverfront  locations.  Solar  projects  within  wetland  areas  are  unlikely  to  comply  with  the  performance   standards  in  the  Wetlands  Protection  Act  regulations.  If  a  solar  installation  is  proposed  in  a  wetland,  a   riverfront  area,  a  floodplain,  or  within  100  feet  of  certain  wetlands,  the  project  proponent  must  file  a   notice  of  intent  (or  application  to  work  in  wetland  areas)  with  the  local  Conservation  Commission,  which   administers  the  Wetlands  Protection  Act  at  the  municipal  level.  Copies  should  also  go  to  MassDEP.  Solar   installations  may  be  sited  near,  but  outside  of  wetlands,  in  a  manner  that  protects  the  functions  of   wetlands  and  that  minimizes  impacts  from  associated  activities  such  as  access  and  maintenance.     Ancillary  structures  related  to  construction  of  a  solar  installation  or  transmission  of  power  may  be   permitted  to  cross  rivers  and  streams  using  best  design  and  management  practices.      

20    

Resources:       More  information  about  the  Wetlands  Protection  Act  requirements  may  be  found  in  the  implementing   regulations  at  310  CMR  10.00:  http://www.mass.gov/eea/agencies/massdep/water/regulations/310-­‐ cmr-­‐10-­‐00-­‐wetlands-­‐protection-­‐act-­‐regulations.html   MassDEP  Guidance  for  Siting  Wind  and  Solar  in  Public  Water  Supply  Land:   http://www.mass.gov/eea/agencies/massdep/water/regulations/wind-­‐and-­‐solar-­‐energy-­‐project-­‐on-­‐ public-­‐water-­‐supply-­‐land.html   MassDEP  Chapter  91  Guidance  for  Renewable  Energy  Projects:   http://www.mass.gov/eea/agencies/massdep/water/reports/chapter-­‐91-­‐licensing-­‐and-­‐renewable-­‐ energy.html      

21    

Glare   Question:  How  important  is  reflectivity  and  potential  visual  impacts  from  solar  projects,  especially  near   airports?   Bottom  Line:  Solar  panels  are  designed  to  reflect  only  about  2  percent  of  incoming  light,  so  issues  with   glare  from  PV  panels  are  rare.    Pre-­‐construction  modeling  can  ensure  that  the  placement  of  solar  panels   prevents  glare.   More  Information:    Solar  panels  are  designed  to  absorb  solar  energy  and  convert  it  into  electricity.  Most   are  designed  with  anti-­‐reflective  glass  front  surfaces  to  capture  and  retain  as  much  of  the  solar   spectrum  as  possible.  Solar  module  glass  has  less  reflectivity  than  water  or  window  glass.  Typical  panels   are  designed  to  reflect  only  about  2  percent  of  incoming  sunlight.  Reflected  light  from  solar  panels  will   have  a  significantly  lower  intensity  than  glare  from  direct  sunlight.       An  analysis  of  a  proposed  25-­‐degree  fixed-­‐tilt  flat-­‐plate  polycrystalline  PV  system  located  outside  of  Las   Vegas,  Nevada  showed  that  the  potential  for  hazardous  glare  from  flat-­‐plate  PV  systems  is  similar  to   that  of  smooth  water  and  not  expected  to  be  a  hazard  to  air  navigation.   Many  projects  throughout  the  US  and  the  world  have  been  installed  near  airports  with  no  impact  on   flight  operations.  United  Kingdom  and  U.S.  aircraft  accident  databases  contain  no  cases  of  accidents  in   which  glare  caused  by  a  solar  energy  facility  was  cited  as  a  factor.     When  siting  solar  PV  arrays  pre-­‐construction  modeling  can  ensure  the  panels  are  placed  in  a  way  that   minimizes  any  potential  glare  to  surrounding  areas.         Resources:     Technical  Guidance  for  Evaluating  Selected  Solar  Technologies  on  Airports,  Federal  Aviation   Administration,  November  2010  (currently  under  review), http://www.faa.gov/airports/environmental/policy_guidance/media/airport_solar_guide.pdf   A  Study  of  the  Hazardous  Glare  Potential  to  Aviators  from  Utility-­‐Scale  Flat-­‐Plate  Photovoltaic  Systems,   Black  &  Veatch  Corporation,  August  2011,  http://www.isrn.com/journals/re/2011/651857/   Solar  Photovoltaic  Energy  Facilities,  Assessment  of  Potential  Impact  on  Aviation,  Spaven  Consulting,   January  2011:  http://www.solarchoice.net.au/blog/solar-­‐panels-­‐near-­‐airports-­‐glare-­‐issue/               22    

Endangered  Species  and  Natural  Heritage   Question:  Who  ensures  that  rare  animal  and  plant  species  and  their  habitats  are  not  displaced  or   destroyed  during  the  construction  of  ground-­‐mounted  solar  PV?   Bottom  Line:  Rules  are  in  place  to  ensure  that  the  installation  of  ground-­‐mounted  solar  arrays  protects   state-­‐listed  rare  species  and  animals  and  plants.    Project  proponents  can  check  with  the  local   Conservation  Commission  to  determine  if  the  footprint  of  the  solar  PV  project  lies  within  a  rare  species   habtat.   More  Information:    The  Massachusetts  Natural  Heritage  and  Endangered  Species  Program  (NEHSP)  was   created  under  the  Massachusetts  Endangered  Species  Act  (MESA)  and  is  responsible  for  protecting  rare   animal  and  plant  species  and  their  habitats  from  being  displaced  or  destroyed.    Specifically,  NEHSP   reviews  projects  proposed  for:   •

•

Priority  Habitats:    These  are  areas  known  to  be  populated  by  state-­‐listed  rare  species  of  animals  or   plants.    Any  project  that  could  result  in  the  alteration  of  more  than  two  acres  of  Priority  Habitat  is   subject  to  NHESP  regulatory  review.    Projects  will  need  to  file  a  MESA  Information  Request  Form,   along  with  a  project  plan,  a  U.S.  Geological  Survey  (USGS)  topographical  map  of  the  site,  and  a  $50   processing  fee.    NHESP  will  let  project  administrators  know  within  30  days  if  the  filing  is  complete,   then  will  determine  within  the  next  60  days  whether  the  project,  as  proposed,  would  result  in  a   “take”  of  state-­‐listed  rare  species  that  might  require  the  project  to  redesign,  scale  down,  or  abandon   its  plan.       Estimated  Habitats:    These  are  a    sub-­‐set  of  Priority  Habitats  that  are  based  on  the  geographical   range  of  state-­‐listed  rare  wildlife  –  particularly  animals  that  live  in  and  around  wetlands.    If  the   project  is  proposed  for  one  of  these  areas  and  the  local  Conservation  Commission  requires  filing  a   Notice  of  Intent  (NOI)  under  the  Wetlands  Protection  Act,  the  project  will  need  to  submit  copies  of   the  NOI,  project  plans  and  a  U.S.  Geological  Survey  (USGS)  topographical  map  to  NHESP.    Within  30   days  of  receiving  this  information,  NHESP  will  send  its  comments  to  the  Conservation  Commission,   with  copies  to  the  project  administrator,  project  consultants,  and  the  Department  of  Environmental   Protection  (MassDEP).  

Resources:     To  learn  more  about  the  NHESP  review  process  and  download  a  MESA  Information  Request  Form,  visit:     http://www.mass.gov/eea/agencies/dfg/dfw/natural-­‐heritage/regulatory-­‐review/mass-­‐endangered-­‐ species-­‐act-­‐mesa/     For  list  of  rare  animal  and  plant  species  in  Massachusetts,  visit:   http://www.mass.gov/eea/agencies/dfg/dfw/natural-­‐heritage/species-­‐information-­‐and-­‐ conservation/mesa-­‐list/list-­‐of-­‐rare-­‐species-­‐in-­‐massachusetts.html    

23    

   

 

 

   

   

24    

Special Permit CEC Solar #1206, LLC Hopkinton, Massachusetts

TABLE OF CONTENTS 1.0

SPECIAL PERMIT FORM .......................................................................................................................... 1-1

2.0

PROJECT NARRATIVE .............................................................................................................................. 2-1

2.1 INTRODUCTION ............................................................................................................................................ 2-1 2.2 EXISTING CONDITIONS ................................................................................................................................. 2-1 2.3 PROPOSED CONDITIONS ............................................................................................................................... 2-2 2.4 COMPLIANCE WITH ZONING BYLAW ............................................................................................................ 2-4 2.4.1 Article XXXI, Commercial Solar Photovoltaic Installation ............................................................... 2-4 2.4.2 Article XXXI, Section 210-203 Administration .................................................................................. 2-7 2.4.2.1 2.4.2.2

2.4.3

Section 210-203.D. Approval Criteria ............................................................................................................ 2-7 Section 210-203.F. ......................................................................................................................................... 2-8

Performance Bond ............................................................................................................................. 2-9

3.0

ABUTTER INFORMATION ............................................................................................................................ 1

4.0

STORMWATER MANAGEMENT INFORMATION .............................................................................. 4-1

5.0

PLANS ............................................................................................................................................................ 5-1

Section 1.0 Special Permit Form Special Permit Application Form

Indicate below the Special Permit(s) requested by this application: Off-Street Parking Facility in a Business (B) District (§ 210-19G) Off-Street Parking Facility in a Downtown Business (BD) District (§ 210-20.3G) Shared and Off-Site Parking (§ 210-124) Parking Space Reduction (§ 210-124.D) Common Driveway (§ 210-120) Hotel Overlay District Use (§ 210-20.3G) Office Park District Use (§ 210-185) Open Space and Landscape Preservation Development Concept Plan (Article XVII) Campus Style Development (Article XIV) Village Housing in Residential Districts (Article XIIIA) Garden Apartments in Residential Districts (Article XIII) Flexible Community Development (Article XI) Commercial Solar Photovoltaic Installations (Article XXXI) Drive-in, Drive-through or Drive-up Uses (§ 210-19.D, § 210-20.3.D, § 210-24.F) Registered Marijuana Dispensary (Article XXXIII) Other ________________________________________________ Supplemental Information Common Driveway Applications Only: N/A

N/A

Will an Approval-Not-Required (ANR) plan be submitted to the Planning Board to create or modify the lots which will share the common driveway? Yes No Will a definitive subdivision plan be submitted to the Planning Board to create or modify the lots which will share the common driveway? Yes No

Hotel Overlay District and Office Park District Applications Only: Not applicable. List specific uses requested: _________________________________________________

________________________________________________________________________ ________________________________________________________________________ Procedure 1. Special Permit applications must be filed by the applicant with the Town Clerk.

11/16/2015

2

2. A public hearing will be scheduled by the Department of Land Use, Planning & Permitting (the “Department”) and the hearing held within 65 days of receipt of a complete application. 3. The Department will publish a legal notice in the MetroWest Daily News, for which the applicant will receive the bill directly from and payable to the newspaper. The Department will notify abutters by first class mail of the public hearing. 4. Either the applicant or a representative is expected to appear at the public hearing to explain the request. 5. The Planning Board must file a decision with the Town Clerk within 90 days of the close of the public hearing. Submission Requirements Applicants must attach and/or submit the following information with the application form. Please note that all materials, including this application, must be submitted on paper and electronically. For guidance as to the format of electronic submissions, see the Planning Board’s adopted Administrative Rules. Fees, in accordance with the Fee Schedule All required copies of plans, materials and documentation, in accordance with the Submission Requirements specific to each Special Permit request. Applications will not be considered complete until all the required materials are submitted. A description of how the special permit, if issued, will be in harmony with the general purpose and intent of the Zoning Bylaw, and how it will conform to any specific decision criteria contained in the Zoning Bylaw applicable to the request. Certified list of abutters within 300 feet of the property, from the Board of Assessors office. The list shall include abutters across any street and in adjacent communities, where applicable. The list of abutters shall have been certified within 90 days of the date of submission. Two envelopes for each abutter on the certified list of abutters, stamped with postage sufficient to send first class mail to each, and 12 envelopes stamped with first class postage for the required notification to abutting communities. An applicant may request, in writing, that the Planning Board waive specific submission requirements. The Board may waive the submission of specific items if it determines that the item is not necessary or not applicable to a specific project or application. If a Special Permit application is submitted concurrently with a Site Plan Review application, then the materials required shall be cumulative, with the exception of the number of envelopes and postage for each abutter and the abutters list. All information may be shown on one set of plans. Fee Schedule If more than one Special Permit is requested by an application, the administrative fee shall be the highest individual fee required regardless of the number of Special Permits requested. The consultant review fee shall be the sum of the two highest required. If this application is submitted concurrently with an application for Site Plan Review, the administrative fee shall be the highest

11/16/2015

3

of the individual fees, and shall not be cumulative1. The consultant review fee shall be the sum of the two highest required.

Special Permit Off Street Parking Facility Shared and Off Site Parking Parking Space Reduction Common Driveways Hotel and/or accessory uses in the Hotel Overlay District Office Park District uses: Residential dormitory component of a conference center; Public transportation facilities Office Park District use: Continuing care retirement community, assisted living facility or similar institution Campus Style Development OSLPD Concept Plan

Garden Apartments in Residential Districts Village Housing

Flexible Community Development

Flexible Community Development – Request for Extension Commercial Solar Photovoltaic Installation Drive-in, Drive-through or Drive-up Uses Registered Marijuana

11/16/2015

Special Permit Application Administrative Consultant Review Fee Fee $1,200.00 $2,000.00

Amendment Administrative Consultant Fee Review Fee $500.00 $1,000.00

$1,200.00

$2,000.00

$500.00

$1,000.00

$300.00 $500.00 $1,800.00

None $1,500.00 $2,000.00

$300.00 $200.00 $500.00

None $500.00 $1,000.00

$600.00

$2,000.00

$500.00

$1,000.00

$1,800.00

$2,000.00

$500.00

$1,000.00

$600.00

$1,000.00

None

None

$600.00 plus $50.00 for every lot above 5 $500.00 plus $10.00 per dwelling unit $150.00 plus $3.00 per dwelling unit $1,000.00

1 to 5 lots: $1,000.00 6 or more lots: $500.00 per lot $2,000.00 plus $500.00 for every 5 acres over 30 acres $2,000.00 plus $500 for every 5 acres over 20 acres $1,000.00 plus $10.00 per dwelling unit

None

None

$400.00

Actual cost

$400.00

Actual cost

$500.00

$50.00

None

$50.00 if no public hearing required; $100.00 if public hearing required NA

$500.00

$1,500.00

$100.00

Actual cost

$250.001

None

$50.00

None

$600.00

$1,500.00

$100.00

Actual cost

4

NA

Dispensary All Other Special Permits

$300.00

$1,000.00

1

$300.00

Actual cost

The administrative fee required with the Special Permit Application for drive-in, drive-through or drive-up uses is $0 if submitted concurrently with an application for Site Plan Review.

11/16/2015

5

Commercial Solar Photovoltaic Installations – Submission Requirements 1. Nine (9) paper copies of the following documents and information in narrative form. Include proposed mitigation where applicable. (a) A statement describing why an application for a Special Permit has been submitted, including the applicant’s objectives and why the Planning Board should grant the request. (b) A statement describing how the proposal complies with the Approval Criteria contained in the Zoning Bylaw. (§ 210-203.D) (c) A list of all other required permits and approvals and the status of each. (d) A description of the current use of the property. (e) Identification of the entities intended to own, operate and maintain the property and the facilities thereon. (f) Proposed forms of deed restrictions and any other existing or proposed agreements between property owners within and outside of the property, if any. (g) An environmental analysis of the impact of the project/facility, including an evaluation of pre-development conditions and post-development conditions on surface and groundwater quality, groundwater recharge, wildlife habitat and corridors, wetlands and bodies of water, including streams and rivers, and all documentation and calculations related thereto. (h) A recommended performance bond amount which may be posted with the Town to guarantee proper maintenance and/or removal of the installation, which shall not exceed the estimated cost of the installation’s removal. Provide information adequate to support the proposed amount. 2. Nine (9) copies of a plan set at a scale of 1” = 40’, on sheet sizes 24” x 36” and one reduced plan set on 11” x 17” paper, prepared by a registered professional engineer unless indicated otherwise by the Board, which shows the information below, at a minimum. (a) Locus plan at a scale of 1” = 800’. (b) The plan set shall include a Zoning Table which lists all applicable area, setback, yard and buffer requirements and the proposed compliance with each. For example, the table shall indicate “Minimum Lot Area” and list “3 acres” in a “Required” column, and in a “Proposed” column it shall indicate the size of the lot containing the installation. (c) Existing Conditions Plan which shows the property, zoning district boundaries, property boundaries and easements, structures on adjacent properties within 50 ft. of the property line, topography at 5 ft. contour intervals, vegetative cover, wetlands, water bodies, historic structures, roads and ways, significant environmental features such as ledge outcrops, scenic views and large trees, and the location, size and shape of existing structures and a notation as to whether they will be removed or retained. 11/16/2015

25

(d) The proposed layout of the property, including the proposed commercial solar photovoltaic installation and other structures with the setbacks and exterior dimensions noted, the limit of site clearing, the location of existing and proposed roads, driveways and utilities, stormwater management system and the layout of proposed parking areas. (e) A detail which depicts the typical solar PV collection structure and their dimensions. (f) The location and dimensions of existing and proposed electrical transformers, inverters and the like, both above and below ground. (g) Proposed methods of screening the premises from abutting property and the street. (h) Proposed security fences. (i) Proposed site lighting including intensity, mounting height, design and direction. (j) Proposed signage.

11/16/2015

26

Section 2.0 Project Narrative

Special Permit Application CEC Solar #1206, LLC Hopkinton, Massachusetts

2.0

PROJECT NARRATIVE

2.1

Introduction The Subject Property (the Property) is located at 147 Lumber Street in Hopkinton, Massachusetts, and is currently a single-family dwelling. An adjacent parcel, off Alexander Street, is also included as part of this proposed development. The 2.9 MW (DC) solar array installation is proposed on a ±11.4-acre portion (the Site) of the larger property (±41.5 acres) located at 147 Lumber Street (the Property) according to Assessor’s information. Refer to Figure 1, Locus Map and Figure 2, Aerial Map.

2.2

Existing Conditions The Property is bounded to the south by single-family residences, to the north by undeveloped and forested land, and to the east and west by single-family residences and undeveloped forested land. The Site lies east of Lumber Street and west of Alexander Road and Daniel Road. The larger Property within which the Site lies is identified as Hopkinton Assessor’s Map R29-15-0 and R30-1-A, two parcels totaling ±41.5 acres owned by Benedict J. and Amy Chirco. The Site currently contains undeveloped forested land which will be cleared of vegetation prior to installation. The land immediately surrounding the Site is predominantly forested and residential. North of the Site, land appears to have been cleared but has not been developed. The proposed location of the Project is approximately 240 feet from the nearest residence on the western side of the Site and ±235 feet from the nearest residence on the eastern side of the Site. The remaining residences in the area are well-removed from the Array. Refer to Section 2.0 Pre-Development Conditions of the Stormwater Management Report included in Section 4.0 of this Application for detailed topographic and soils information. There are two areas of Bordering Vegetated Wetlands (BVW) located on-site. The first area is located north of the existing access driveway, along Lumber Street, on the western side of the Property. This BVW consists of forested red maple swamp associated with a stream located on the Site, of which the access driveway crosses. The second BVW is located on the eastern portion of the Property and consists of a red maple swamp. A Notice of Intent will be filed for the portions of work subject to the Conservation Commission’s jurisdiction subsequent to the filing of this application. According to the Massachusetts Cultural Resource Information System (MACRIS), there are no historical resources located on the Site. Additionally, the proposed work does not involve activities that would adversely impact potential surrounding historic resources, such as the residences on either side of the driveway connection at Lumber Street.

Project Narrative

2-1

Special Permit Application CEC Solar #1206, LLC Hopkinton, Massachusetts

According to the Massachusetts Natural Heritage Atlas 13th Edition, dated October 1, 2008, and confirmed current with MassGIS information on May 31, 2017, the Site is not located within Natural Heritage and Endangered Species Program (NHESP) designated Priority Habitat of Rare Species or Estimated Habitat of Rare Wildlife. There are no potential or certified vernal pools identified by NHESP within the Site. 2.3

Proposed Conditions The proposed system size will be a 2.9 MW (DC) facility proposed on a ±11.4-acre portion (the Site) of the larger Property (±41.5 acres) located at 147 Lumber Street. Relevant details relating to the solar system components are included on the enclosed plans. The Property is located in two residential zoning districts, the Agriculture (A) district and the Residential B (RB) district. However, the Site is located solely within the A district. In terms of zoning requirements, the A District is more restrictive than the RB district; therefore, the Project will conform to the requirements of the A district, per the Hopkinton Zoning Bylaw. As required and detailed herein, the proposed location of the solar array area provides a minimum 60-foot setback from Lumber Street (front yard), and minimum 30-foot setbacks from the side and rear yards. These setbacks are measured from the security fence surrounding the solar panels, as required in the Zoning Bylaw. The Array will encompass approximately ±9.5 acres (fenced area) and will connect to the electrical grid at Lumber Street. The Array has been designed so that the clearing for the Array and security fence will be located outside of jurisdictional wetland areas as established by the Hopkinton Wetlands Protection Bylaw. A vegetated buffer along the access drive, south of the western Array, will be maintained with a combination of Green Giant Arborvitae (Thuja ‘Green Giant’) and Woodwardii American Arborvitae (Thuja occidentalis ‘Woodwardii’). The Woodwardii American Arborvitae will be planted five (5)-feet on-center and the Green Giant Arbovitae will be planted eight (8)-feet on-center. A total of 12 Woodwardii Arborvitae are proposed to be planted and a total of 134 Green Giant Arborvitae are proposed to be planted. Refer to Plans in Section 5.0. A seven-foot high, galvanized chain link fence, with no top horizontal rail (to mitigate potential visual impact), will be installed around the perimeter of the array, outside of the required zoning setbacks from adjacent property lines. The fence will be a wooden stockade-style along the western boundary of the southern portion of the array. The driveway accessing the Array is an existing paved driveway and will be extended and/or improved to adequately provide access for emergency and maintenance vehicles.

Project Narrative

2-2

Special Permit Application CEC Solar #1206, LLC Hopkinton, Massachusetts

Construction access to the Site will be gained via the existing driveway on Lumber Street. The proposed construction sequence is provided below: 

Contractor shall have the limit of all erosion control barriers staked prior to any construction activities.



Erosion control and stone construction entrance shall be installed and inspected prior to initiating earthwork.



All greater than 3:1 slopes, shall be stabilized with an erosion control blanket.



Install the solar panel support posts and racks.



Install the solar panels and electrical conduits.



Loam and seed all disturbed areas as construction progresses.



Provide ongoing maintenance of disturbed areas until disturbed areas are 100% stabilized.



Construction sequence may vary to minimize disturbance on-site and all erosion controls will be maintained until full stabilization.



All material modifications as determined by the Building Inspector to be a major modification for the Array made after the issuance of the required building permit shall require approval by the Planning Board.



All construction activity shall occur between the hours of 7:00 AM and 5:00 PM on Monday through Saturday, only. Construction activity includes staging, deliveries, equipment warm up, or other supporting construction activities.



Once the Project is complete, there will be no outside storage of equipment or solar panels on the Site.



An as-built plan shall be submitted and approved by the Hopkinton Building Inspector and Hopkinton Planning Board prior to the issuance of an occupancy permit.



Vegetation control on the Site shall be mechanical only and no pesticides or other chemical products shall be used.

Project Narrative

2-3

Special Permit Application CEC Solar #1206, LLC Hopkinton, Massachusetts

Refer to Section 3.0 Post-Development Conditions of the Stormwater Management Report included in Section 4.0 of this application regarding information on existing and proposed hydrology and compliance with the DEP Stormwater Management Policy. Potential soil erosion will be mitigated by the use of straw bales with silt fencing as erosion control barriers, with straw wattles or some other intermediate erosion control measure inside of the perimeter of ECBs, given the long uninterrupted slopes down to the resource areas. Additionally, the construction entrance will be stabilized crushed stone, temporary sedimentation basins and potentially catch basin sediment bags will also be utilized where appropriate. Refer to the attached plan set as well as the Site Owner’s Manual in Section 4.0 for detailed information regarding the best management practices to be used to control soil erosion and sedimentation. In 2010, Hopkinton was designated as a Green Community by the Department of Energy Resources (DOER). The Massachusetts Green Communities Program goals include helping municipalities find clean energy solutions that reduce long-term energy costs and strengthen local economies. DOER selection criteria for a municipality to become a Green Community include providing as-of-right siting in designated locations for renewable/alternative energy generation. Additionally, the Hopkinton Sustainable Green Committee’s mission “is to promote sustainable and environmentally responsible practices in the Town of Hopkinton. The Committee will assist town government, business and residents to implement sustainable policies and practices in the areas of energy, agriculture, conservation and commerce. The Committee will increase the public's awareness of important environmental issues through education and outreach. By fostering environmentally friendly practices in Hopkinton, the Committee aims to enhance the quality of life for our residents, visitors and future generations.” The proposed Project will further the Commonwealth’s and Town of Hopkinton’s commitment to environmental protection through various approaches, including renewable energy sources. 2.4

Compliance with Zoning Bylaw A narrative describing how the proposed Lumber Street Solar Array complies with the applicable requirements of the Zoning Bylaw, specifically Article XXXI, Commercial Solar Photovoltaic Installation, is provided below. 2.4.1 Article XXXI, Commercial Solar Photovoltaic Installation The Project is in full compliance with the Solar Bylaw, Article XXXI, § 210-202, as detailed below. A. A commercial solar photovoltaic installation may be erected, upon the issuance of a special permit by the Planning Board, on a lot containing a minimum of three (3) acres.

Project Narrative

2-4

Special Permit Application CEC Solar #1206, LLC Hopkinton, Massachusetts

The Subject Property is approximately 41.5 acres. The fenced area containing the solar panels will cover approximately 9.2 acres, and the overall Site is approximately 14.1 acres. B. All setback, yard, buffer and screening requirements applicable in the zoning district in which the installation is located shall apply. The proposed use conforms to all setback, yard, buffer, and screening requirements, as depicted on the enclosed plans. As stipulated in the Zoning Bylaw, the setbacks apply to the security fence surrounding the solar panels. C. All security fences surrounding the installations shall be set back from the property line a distance equal to the setback applicable to buildings within the zoning district in which the installation is located. All security fences conform to the required setback limits, as previously discussed. It is understood that the setback requirement is applicable to the security fences and not the solar panels. D. The provisions of Article XX, Site Plan Review, shall not apply to commercial solar photovoltaic installations. Site Plan Review will not be required for the Project. E. The visual impact of the commercial solar photovoltaic installation, including all accessory structures and appurtenances, shall be mitigated. All accessory structures and appurtenances shall be architecturally compatible with each other. Whenever reasonable, structures shall be shielded from view by vegetation and/or joined and clustered to avoid adverse visual impacts. Methods such as the use of landscaping, natural features and fencing may be utilized. There is anticipated to be minimal, if any, visual impact due to the proposed installation. A wooded wetland is located between the proposed Array and the residential houses to the east of the Site, providing an approximately 50foot wide vegetated buffer between these uses. To the west of the Site, the closest point of the Array is set back approximately 100 feet from the property line and more than 240 feet from the residential structure, and will have a buffer of existing trees between the two uses. The property to the north of the Site is a facility for the Hopkinton Sportsmen’s Association, and is currently wooded and undeveloped, and therefore no additional screening for this property is needed. The Array is set back from Lumber Street and will be screened from view by existing vegetation.

Project Narrative

2-5

Special Permit Application CEC Solar #1206, LLC Hopkinton, Massachusetts

The Property is currently undeveloped forested land and a single-family residence. The closest residential structure is approximately 135 feet from the proposed Array. The residential structures surrounding the Site will have the Array shielded from view by heavy vegetation comprised of trees and shrubs. It is anticipated that there will be little to no visual impact to surrounding properties by the proposed Project. F. Lighting shall not be permitted unless required by the Planning Board or by the State Building Code. Where used, lighting shall be directed downward and full cut-off fixtures shall be used. Lighting is not proposed. If it becomes necessary, due to Planning Board or Building Code requirements, it will be directed downward and full cut-off fixtures will be used. G. All utility connections from the commercial solar photovoltaic installation shall be underground unless otherwise specifically permitted otherwise by the Planning Board in the special permit. Electrical transformers and inverters to enable utility interconnections may be above ground if required by the utility provider. The majority of the utility connections will be located underground, however, it is necessary for the interconnection at Lumber Street to be above-ground, as the equipment includes safety equipment for shutting down power to/from the Site as well as metering equipment. Similarly, inverters within the Site must be above-ground for access and maintenance. Therefore, the Applicant respectfully requests that the Planning Board allow the above-ground equipment as depicted on the enclosed plans in the Special Permit. H. Clearing of natural vegetation shall be limited to the minimum necessary for the construction, operation and maintenance of the commercial solar photovoltaic installation except as otherwise prescribed by applicable laws, regulations and bylaws or the special permit. Vegetative clearing has been minimized to the extent practicable for the installation and operation of the Array. Vegetation within the fenced area will be cleared and stumps removed, disturbed areas will be seeded with a native seed mix. Grading has been minimized to the extent practicable. Where grading is not proposed, existing topsoil will remain in place. Where grading is necessary, loam will be imported as needed. Work proposed outside of the fenced area includes grading, clearing of vegetation, and seeding of disturbed areas with a native seed mix.

Project Narrative

2-6

Special Permit Application CEC Solar #1206, LLC Hopkinton, Massachusetts

I. The commercial solar photovoltaic installation owner or operator shall maintain the facility in good condition. Maintenance shall include, but not be limited to, painting, structural repairs, continued compliance with landscaping and screening requirements, and integrity of security measures. The owner or operator shall be responsible for the maintenance of any access roads serving the installation. The commercial solar photovoltaic installation owner will maintain the facility in good condition. The owner/operator will be responsible for the maintenance of any access roads serving the property. 2.4.2 Article XXXI, Section 210-203 Administration 2.4.2.1 Section 210-203.D. Approval Criteria In reviewing any application for special permit pursuant to this Article, the Planning Board shall give due consideration to promoting the public health, safety, convenience and welfare; shall encourage the most appropriate use of land and shall permit no building or use that is injurious, noxious, offensive or detrimental to its neighborhood. Before the Planning Board may issue a special permit, it shall determine each of the following: (1) The commercial solar photovoltaic installation conforms to the provisions of this Article. The proposed solar photovoltaic installation conforms to the provisions of Article XXXI. Please refer to Section 2.4.1 of this application. (2) The commercial solar photovoltaic installation will not be detrimental to the neighborhood or the Town. The proposed installation is not anticipated to be detrimental to the neighborhood or Town, but is anticipated to provide a clean and safe alternative energy source on underutilized land, as detailed herein. (3) Environmental features of the site and surrounding areas are protected and specifically surrounding areas will be protected from the proposed use by provision of adequate surface water drainage.

Project Narrative

2-7

Special Permit Application CEC Solar #1206, LLC Hopkinton, Massachusetts

Site selection and design have been undertaken to impact the natural environment as minimally as possible, as detailed herein. The Project is anticipated to have minimal impact to natural resources on and around the Site, and native landscaping screening and mitigation plantings will mitigate potential impacts. The Site has been designed in compliance with applicable local and state stormwater requirements, and the post- development stormwater runoff rates will not exceed the pre-development rates. Refer to the Stormwater Management Report in Section 4.0 for additional information regarding post-development drainage. (4) The proposed use is in harmony with the general purpose and intent of this Chapter. The proposed use as a solar photovoltaic installation is in harmony with the general purpose and intent of zoning in that it serves to preserve the health and welfare of the public. The proposed Project is anticipated to provide safe, clean alternative energy to the community through energy production without adverse impact to water resources, natural resources, air quality, and visual resources. 2.4.2.2 Section 210-203.F. In reviewing any application for a special permit, the Planning Board shall give due consideration to promoting the public health, safety, convenience and welfare; shall encourage the most appropriate use of land and shall permit no building or use that is injurious, noxious, offensive or detrimental to its neighborhood. The proposed solar installation is anticipated to promote public health, safety, convenience, and welfare by providing the community with a safe, clean alternative energy source with little to no impact on natural resources, including air quality and water resources. The Property is currently underutilized, and the proposed use is a more appropriate use of the land as it is anticipated to provide a safe, clean alternative energy source on surplus land. The benefit derived from the land, both for the property owner, Applicant, and the community, is anticipated to be greater than the existing use by providing clean, safe alternative energy with minimal impacts.

Project Narrative

2-8

Special Permit Application CEC Solar #1206, LLC Hopkinton, Massachusetts

The use proposed is not anticipated to be injurious, noxious, offensive, or detrimental to the neighborhood or Town. The proposed use is anticipated to have a positive impact to the surrounding neighborhood and Town. 2.4.3 Performance Bond The Applicant will work with the Planning Board to determine an appropriate fee to serve as the performance bond, to be conditioned as part of approval.

Project Narrative

2-9

Section 3.0 Abutter Information Certified Abutter List

Section 4.0 Stormwater Management Information Checklist for Stormwater Report Stormwater Management Report

CEC Solar #1206, LLC Stormwater Management Report Hopkinton, Massachusetts 283600RP001A

TABLE OF CONTENTS 1.0

INTRODUCTION .............................................................................................................................................. 1

2.0

PRE-DEVELOPMENT CONDITIONS........................................................................................................... 2

2.1 2.2 2.3 3.0

SITE CONDITIONS ............................................................................................................................................ 2 SOIL DESCRIPTION .......................................................................................................................................... 2 HYDROLOGIC ANALYSIS .................................................................................................................................. 3

POST-DEVELOPMENT CONDITIONS ........................................................................................................ 3

3.1 3.2 3.3 3.4 3.5 3.6

DESIGN STRATEGY ........................................................................................................................................... 3 HYDROLOGIC ANALYSIS .................................................................................................................................. 3 STORMWATER MANAGEMENT CONTROLS SIZING ............................................................................................ 3 COMPLIANCE WITH DEP STORMWATER MANAGEMENT STANDARDS .............................................................. 3 ILLICIT DISCHARGE COMPLIANCE STATEMENT ................................................................................................ 6 DEP’S CHECKLIST FOR A STORMWATER REPORT ............................................................................................ 7

LIST OF APPENDICES APPENDIX A: SOIL DATA APPENDIX B: PRE-DEVELOPMENT HYDROLOGIC ANALYSIS APPENDIX C: POST-DEVELOPMENT HYDROLOGIC ANALYSIS APPENDIX D: DRAWDOWN & RIPRAP-SIZING CALCULATIONS APPENDIX E: SITE OWNER’S MANUAL APPENDIX F: STORMWATER POLLUTION PREVENTION PLAN

Table of Contents

i

CEC Solar #1206, LLC Stormwater Management Report Hopkinton, Massachusetts 283600RP001

1.0

INTRODUCTION

The proposed project includes a stormwater management system designed to mitigate potential impacts the proposed project could have on the existing watershed. Stormwater controls have been proposed to control peak runoff rates, provide water quality, promote groundwater recharge, and sediment removal. The proposed system has been designed to comply with: •

The 2008 Massachusetts Department of Environmental Protection (DEP) Stormwater Management Handbook,

• •

The Massachusetts Wetland Protection Act (310 CMR 10.00), and Town of Hopkinton Wetlands Protection Regulations

The pre- and post-development hydrologic conditions were modeled using HydroCADTM version 10.00 to demonstrate that post-development stormwater runoff rates will be less than or equal to the pre-development rates. Watershed maps with soil types as well as detailed analysis of the model results are also included. The following table summarizes the peak runoff rates and volumes for the pre- and post-development conditions. Table 1: Pre- & Post-development Peak Runoff Rate Comparison, units are in cubic feet per second (cfs).

Storm Event Design Point 1 Design Point 2 Design Point 3

2 Year Pre Post 0.00 0.00 0.22 0.19 0.22 0.14

10 Year Pre Post 0.04 0.00 1.95 1.81 2.35 1.85

25 Year Pre Post 0.27 0.26 4.21 4.10 5.29 5.19

100 Year Pre Post 3.08 2.24 10.21 10.19 13.23 12.24

1

CEC Solar #1206, LLC Stormwater Management Report Hopkinton, Massachusetts 283600RP001

2.0

PRE-DEVELOPMENT CONDITIONS

2.1

Site Conditions The proposed ground-mounted solar facility is located on an approximately 11.4-acre site (the Site) which is partially developed and occupied by a single-family residence. The solar array is proposed within an area that is comprised of predominantly woodland vegetation. The array is accessed off of the existing driveway associated with the dwelling on Lumber Street. The array is approximately centered on a high-point. Runoff from the Site drains to the east and to the west. There are on-site bordering vegetated wetlands (BVW) at the eastern perimeter of the Site as well as a potential vernal pool (PVP) and associated isolated vegetated wetland (IVW) at the southeastern quadrant. There is also a BVW at the western perimeter of the Site (adjacent to Lumber Street). The resource areas at northeastern and western portions of the Site ultimately flow to the north. The southeastern potion of the Site (including the PVP and IVW) flow to the east and south. These three locations described serve as the design points evaluated in the hydrologic analysis. A portion of the Site is within an Outstanding Resource Water (ORW). As described below, the project is proposed in accordance with Massachusetts DEP Stormwater Management Policy.

2.2

Soil Description The Natural Resources Conservation Service (NRCS) Web Soil Survey lists the on-site soils as Canton Fine Sandy Loam, Narragansett Silt Loam, and some areas of Ridgebury Fine Sandy Loam. Canton Fine Sandy Loam is a very deep, well-drained soil on glaciated uplands. The typical soil profile is comprised of layers of fine sandy loam over gravelly fine sandy loam, over gravelly loamy sand. NRCS classifies these soils as Hydrologic Soil Group (HSG) “A” (extremely bouldery) & “B” (extremely stony). Narragansett Silt Loam is a deep, well drained soil on glacial till plains and ground moraine. The typical soil profile is comprised of layers of silt loam over very gravelly loamy sand. NRCS classifies this soil as HSG “A”. Ridgebury Fine Sandy Loam is a very deep, poorly drained to somewhat poorly drained soil on glacial till uplands. The typical soil profile is comprised of layers of fine sandy loam over loamy fine sand, sand, and gravelly coarse sand. NRCS classifies this soil as HSG “D”.

2

CEC Solar #1206, LLC Stormwater Management Report Hopkinton, Massachusetts 283600RP001

2.3

Hydrologic Analysis Sub-catchment areas were delineated based on existing runoff patterns and topographic information. This information is shown on the Pre-Development Conditions Hydrologic Areas Map included in Appendix B. Summaries of each area with respect to Curve Number and Time of Concentration calculations can be found in the model results also in Appendix B.

3.0

POST-DEVELOPMENT CONDITIONS

3.1

Design Strategy The proposed solar array will include stormwater management measures to control peak rates of runoff from the Site. During the design phase of the site layout, consideration was given to minimizing the impact on the existing Site hydrology. To achieve this, grading was minimized to the maximum extent practicable and the Site was designed to match existing terrain where feasible, in order to maintain drainage patterns to maximum extent practicable. Stormwater runoff is directed to the proposed Best Management Practices (BMPs) via overland flow, with diversion berms and conveyance swales, if needed.

3.2

Hydrologic Analysis The established design points used in the pre-development conditions analysis were used in the post-development analysis for direct comparison. The tributary areas and flow paths were modified to reflect post-development conditions. See Appendix C for the Post- Development Conditions Hydrologic Areas Map. Summaries of each area with respect to Curve Number and Time of Concentration calculations can be found in the model results in Appendix C.

3.3

Stormwater Management Controls Sizing Infiltration Basin The three proposed stormwater infiltration basins have been designed to reduce peak runoff rates. All three basins have one to three pipe outlets and a riprap emergency spillway. The basins have been modeled with a conservative infiltration rate of 0.27 inches per hour consistent with HSG “C” soils, though the basins are proposed in areas mapped as HSG “A” & “B”. The basins dewater within 72 hours, as demonstrated by the drawdown calculations in Appendix D.

3.4

Compliance with DEP Stormwater Management Standards The proposed stormwater management system was designed in compliance with the ten (10) DEP Stormwater Management Standards. The following summary provides key information related to the proposed stormwater management system, its design elements, and mitigation measures for potential impacts.

3

CEC Solar #1206, LLC Stormwater Management Report Hopkinton, Massachusetts 283600RP001

STANDARD 1:

No new stormwater conveyance (e.g. outfalls) may discharge untreated stormwater directly to or cause erosion in wetlands or waters of the Commonwealth.

Existing drainage patterns will be maintained. There are no contiguous impervious ground surfaces proposed, with the exception of relatively minor equipment pads. Three infiltration basins have been designed to mitigate stormwater runoff rates associated with the proposed project. Outlets from the basins have been designed to minimize the potential for erosion.

STANDARD 2:

Stormwater management systems shall be designed so that postdevelopment peak discharge rates do not exceed pre-development peak discharge rates.

The stormwater management design will control post-development peak discharge rates for the 2-, 10-, 25-, and 100-year, 24-hour storms so as to maintain pre-development peak discharge rates. Refer to Section 1.0 Introduction for a summary of the peak runoff rates.

STANDARD 3:

Loss of annual recharge to groundwater shall be eliminated or minimized through the use of environmentally sensitive site design, low impact development techniques, stormwater management practices and good operation and maintenance. At a minimum, the annual recharge from the post-development site shall approximate the annual recharge from pre-development conditions based on soil types. This Standard is met when the stormwater management system is designed to infiltrate the required recharge volume as determined in accordance with the Massachusetts Stormwater Handbook.

Groundwater recharge will be maintained as no contiguous impervious ground surfaces are proposed as part of this project, with the exception of two relatively small equipment pads. The stormwater management system includes infiltration basins that will promote groundwater recharge onsite. As a result, annual recharge from the post-development site will approximate the annual recharge from the site under pre-development conditions.

STANDARD 4:

Stormwater management systems shall be designed to remove 80% of the average annual post-construction load of Total Suspended Solids (TSS).

4

CEC Solar #1206, LLC Stormwater Management Report Hopkinton, Massachusetts 283600RP001

The project does not include proposed impervious surfaces requiring treatment, therefore the 80% TSS removal requirement does not apply. A Site Owner’s Manual has been developed to comply with the Long-Term Pollution Prevention Plan (Standard 4) and the Long-Term Operation and Maintenance Plan (Standard 9) requirements of the 2008 Massachusetts Department of Environmental Protection (MassDEP) Stormwater Management Standards. The Manual outlines source control and pollution prevention measures and maintenance requirements of stormwater BMPs associated with the proposed project.

STANDARD 5:

For land uses with higher potential pollutant loads (LUHPPLs), source control and pollution prevention shall be implemented in accordance with the Massachusetts Stormwater Handbook to eliminate or reduce the discharge of stormwater runoff from such land uses to the maximum extent practicable.

The proposed project is not associated with stormwater discharges from land uses with higher potential pollutant loads.

STANDARD 6:

Stormwater discharges to critical areas must utilize certain stormwater management BMPs approved for critical areas. Critical areas are Outstanding Resource Waters, shellfish beds, swimming beaches, coldwater fisheries and recharge areas for public water supplies.

The proposed BMPs are consistent with the Stormwater Management Handbook for use within the ORW critical area. Impervious areas requiring treatment are not proposed as part of this project.

STANDARD 7:

Redevelopment of previously developed sites must meet the Stormwater Management Standards to the maximum extent practicable. However, if it is not practicable to meet all the Standards, new (retrofitted or expanded) stormwater management systems must be designed to improve existing conditions.

The proposed project is new development, and therefore this standard does not apply.

5

CEC Solar #1206, LLC Stormwater Management Report Hopkinton, Massachusetts 283600RP001

STANDARD 8:

A plan to control construction-related impacts during erosion, sedimentation and other pollutant sources during construction and land disturbance activities (construction period erosion, sedimentation, and pollution prevention plan) shall be developed and implemented.

A draft Stormwater Pollution Prevention Plan (SWPPP) has been developed to comply with Section 3 of the NPDES Construction General Permit for Stormwater Discharges; therefore the requirements of Standard 8 are fulfilled.

STANDARD 9:

A Long-Term Operation and Maintenance (O&M) Plan shall be developed and implemented to ensure that stormwater management systems function as designed.

The Site Owner’s Manual complies with the Long-Term Pollution Prevention Plan (Standard 4) and the Long-Term Operation and Maintenance Plan (Standard 9) requirements of the 2008 Massachusetts Department of Environmental Protection (MassDEP) Stormwater Management Standards. The Manual outlines source control and pollution prevention measures and maintenance requirements of the stormwater BMPs associated with the proposed development.

STANDARD 10:

All illicit discharges to the stormwater management system are prohibited.

There will be no illicit discharges to the proposed stormwater management system associated with the proposed project. An Illicit Discharge Compliance Statement is provided on the following page.

3.5

Illicit Discharge Compliance Statement

6

CEC Solar #1206, LLC Stormwater Management Report Hopkinton, Massachusetts 283600RP001

An illicit discharge is any discharge to a municipal separate storm sewer that is not comprised entirely of stormwater, discharges from fire-fighting activities, and certain non-designated non-stormwater discharges. To the best of my knowledge, no detectable illicit discharge exists on site. The site plans included with this report detail the storm sewers that convey stormwater on the site and demonstrate that these systems do not include the entry of an illicit discharge. A Site Owner’s Manual is also included, which contains the Long Term Pollution Plan that outlines measures to prevent future illicit discharges. As the Site Owner, I will ultimately be responsible for implementing the Long Term Pollution Prevention Plan.

Signature:

_______________________________________ Owner’s Name

DEP’s Checklist for a Stormwater Report

7

Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program

Checklist for Stormwater Report A. Introduction Important: When filling out forms on the computer, use only the tab key to move your cursor - do not use the return key.

A Stormwater Report must be submitted with the Notice of Intent permit application to document compliance with the Stormwater Management Standards. The following checklist is NOT a substitute for the Stormwater Report (which should provide more substantive and detailed information) but is offered here as a tool to help the applicant organize their Stormwater Management documentation for their Report and for the reviewer to assess this information in a consistent format. As noted in the Checklist, the Stormwater Report must contain the engineering computations and supporting information set forth in Volume 3 of the Massachusetts Stormwater Handbook. The Stormwater Report must be prepared and certified by a Registered Professional Engineer (RPE) licensed in the Commonwealth. The Stormwater Report must include: • The Stormwater Checklist completed and stamped by a Registered Professional Engineer (see page 2) that certifies that the Stormwater Report contains all required submittals.1 This Checklist is to be used as the cover for the completed Stormwater Report. • Applicant/Project Name • Project Address • Name of Firm and Registered Professional Engineer that prepared the Report • Long-Term Pollution Prevention Plan required by Standards 4-6 • Construction Period Pollution Prevention and Erosion and Sedimentation Control Plan required by Standard 82 • Operation and Maintenance Plan required by Standard 9 In addition to all plans and supporting information, the Stormwater Report must include a brief narrative describing stormwater management practices, including environmentally sensitive site design and LID techniques, along with a diagram depicting runoff through the proposed BMP treatment train. Plans are required to show existing and proposed conditions, identify all wetland resource areas, NRCS soil types, critical areas, Land Uses with Higher Potential Pollutant Loads (LUHPPL), and any areas on the site where infiltration rate is greater than 2.4 inches per hour. The Plans shall identify the drainage areas for both existing and proposed conditions at a scale that enables verification of supporting calculations. As noted in the Checklist, the Stormwater Management Report shall document compliance with each of the Stormwater Management Standards as provided in the Massachusetts Stormwater Handbook. The soils evaluation and calculations shall be done using the methodologies set forth in Volume 3 of the Massachusetts Stormwater Handbook. To ensure that the Stormwater Report is complete, applicants are required to fill in the Stormwater Report Checklist by checking the box to indicate that the specified information has been included in the Stormwater Report. If any of the information specified in the checklist has not been submitted, the applicant must provide an explanation. The completed Stormwater Report Checklist and Certification must be submitted with the Stormwater Report.

1

The Stormwater Report may also include the Illicit Discharge Compliance Statement required by Standard 10. If not included in the Stormwater Report, the Illicit Discharge Compliance Statement must be submitted prior to the discharge of stormwater runoff to the post-construction best management practices. 2

For some complex projects, it may not be possible to include the Construction Period Erosion and Sedimentation Control Plan in the Stormwater Report. In that event, the issuing authority has the discretion to issue an Order of Conditions that approves the project and includes a condition requiring the proponent to submit the Construction Period Erosion and Sedimentation Control Plan before commencing any land disturbance activity on the site.

283600swcheck.doc • 04/01/08

Stormwater Report Checklist • Page 1 of 8

Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program

Checklist for Stormwater Report Checklist (continued) LID Measures: Stormwater Standards require LID measures to be considered. Document what environmentally sensitive design and LID Techniques were considered during the planning and design of the project: No disturbance to any Wetland Resource Areas Site Design Practices (e.g. clustered development, reduced frontage setbacks) Reduced Impervious Area (Redevelopment Only) Minimizing disturbance to existing trees and shrubs LID Site Design Credit Requested: Credit 1 Credit 2 Credit 3 Use of “country drainage” versus curb and gutter conveyance and pipe Bioretention Cells (includes Rain Gardens) Constructed Stormwater Wetlands (includes Gravel Wetlands designs) Treebox Filter Water Quality Swale Grass Channel Green Roof Other (describe):

Standard 1: No New Untreated Discharges No new untreated discharges Outlets have been designed so there is no erosion or scour to wetlands and waters of the Commonwealth Supporting calculations specified in Volume 3 of the Massachusetts Stormwater Handbook included.

283600swcheck.doc • 04/01/08

Stormwater Report Checklist • Page 3 of 8

Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program

Checklist for Stormwater Report Checklist (continued) Standard 2: Peak Rate Attenuation Standard 2 waiver requested because the project is located in land subject to coastal storm flowage and stormwater discharge is to a wetland subject to coastal flooding. Evaluation provided to determine whether off-site flooding increases during the 100-year 24-hour storm. Calculations provided to show that post-development peak discharge rates do not exceed predevelopment rates for the 2-year and 10-year 24-hour storms. If evaluation shows that off-site flooding increases during the 100-year 24-hour storm, calculations are also provided to show that post-development peak discharge rates do not exceed pre-development rates for the 100-year 24hour storm. Standard 3: Recharge Soil Analysis provided. Required Recharge Volume calculation provided. Required Recharge volume reduced through use of the LID site Design Credits. Sizing the infiltration, BMPs is based on the following method: Check the method used. Static

Simple Dynamic

Dynamic Field1

Runoff from all impervious areas at the site discharging to the infiltration BMP. Runoff from all impervious areas at the site is not discharging to the infiltration BMP and calculations are provided showing that the drainage area contributing runoff to the infiltration BMPs is sufficient to generate the required recharge volume. Recharge BMPs have been sized to infiltrate the Required Recharge Volume. Recharge BMPs have been sized to infiltrate the Required Recharge Volume only to the maximum extent practicable for the following reason: Site is comprised solely of C and D soils and/or bedrock at the land surface M.G.L. c. 21E sites pursuant to 310 CMR 40.0000 Solid Waste Landfill pursuant to 310 CMR 19.000 Project is otherwise subject to Stormwater Management Standards only to the maximum extent practicable. Calculations showing that the infiltration BMPs will drain in 72 hours are provided. Property includes a M.G.L. c. 21E site or a solid waste landfill and a mounding analysis is included.

1

80% TSS removal is required prior to discharge to infiltration BMP if Dynamic Field method is used.

283600swcheck.doc • 04/01/08

Stormwater Report Checklist • Page 4 of 8

Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program

Checklist for Stormwater Report Checklist (continued) Standard 3: Recharge (continued) The infiltration BMP is used to attenuate peak flows during storms greater than or equal to the 10year 24-hour storm and separation to seasonal high groundwater is less than 4 feet and a mounding analysis is provided. Documentation is provided showing that infiltration BMPs do not adversely impact nearby wetland resource areas. Standard 4: Water Quality The Long-Term Pollution Prevention Plan typically includes the following: • Good housekeeping practices; • Provisions for storing materials and waste products inside or under cover; • Vehicle washing controls; • Requirements for routine inspections and maintenance of stormwater BMPs; • Spill prevention and response plans; • Provisions for maintenance of lawns, gardens, and other landscaped areas; • Requirements for storage and use of fertilizers, herbicides, and pesticides; • Pet waste management provisions; • Provisions for operation and management of septic systems; • Provisions for solid waste management; • Snow disposal and plowing plans relative to Wetland Resource Areas; • Winter Road Salt and/or Sand Use and Storage restrictions; • Street sweeping schedules; • Provisions for prevention of illicit discharges to the stormwater management system; • Documentation that Stormwater BMPs are designed to provide for shutdown and containment in the event of a spill or discharges to or near critical areas or from LUHPPL; • Training for staff or personnel involved with implementing Long-Term Pollution Prevention Plan; • List of Emergency contacts for implementing Long-Term Pollution Prevention Plan. A Long-Term Pollution Prevention Plan is attached to Stormwater Report and is included as an attachment to the Wetlands Notice of Intent. Treatment BMPs subject to the 44% TSS removal pretreatment requirement and the one inch rule for calculating the water quality volume are included, and discharge: is within the Zone II or Interim Wellhead Protection Area is near or to other critical areas is within soils with a rapid infiltration rate (greater than 2.4 inches per hour) involves runoff from land uses with higher potential pollutant loads. The Required Water Quality Volume is reduced through use of the LID site Design Credits. Calculations documenting that the treatment train meets the 80% TSS removal requirement and, if applicable, the 44% TSS removal pretreatment requirement, are provided.

283600swcheck.doc • 04/01/08

Stormwater Report Checklist • Page 5 of 8

Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program

Checklist for Stormwater Report Checklist (continued) Standard 4: Water Quality (continued) The BMP is sized (and calculations provided) based on: The ½” or 1” Water Quality Volume or The equivalent flow rate associated with the Water Quality Volume and documentation is provided showing that the BMP treats the required water quality volume. The applicant proposes to use proprietary BMPs, and documentation supporting use of proprietary BMP and proposed TSS removal rate is provided. This documentation may be in the form of the propriety BMP checklist found in Volume 2, Chapter 4 of the Massachusetts Stormwater Handbook and submitting copies of the TARP Report, STEP Report, and/or other third party studies verifying performance of the proprietary BMPs. A TMDL exists that indicates a need to reduce pollutants other than TSS and documentation showing that the BMPs selected are consistent with the TMDL is provided. Standard 5: Land Uses With Higher Potential Pollutant Loads (LUHPPLs) The NPDES Multi-Sector General Permit covers the land use and the Stormwater Pollution Prevention Plan (SWPPP) has been included with the Stormwater Report. The NPDES Multi-Sector General Permit covers the land use and the SWPPP will be submitted prior to the discharge of stormwater to the post-construction stormwater BMPs. The NPDES Multi-Sector General Permit does not cover the land use. LUHPPLs are located at the site and industry specific source control and pollution prevention measures have been proposed to reduce or eliminate the exposure of LUHPPLs to rain, snow, snow melt and runoff, and been included in the long term Pollution Prevention Plan. All exposure has been eliminated. All exposure has not been eliminated and all BMPs selected are on MassDEP LUHPPL list. The LUHPPL has the potential to generate runoff with moderate to higher concentrations of oil and grease (e.g. all parking lots with >1000 vehicle trips per day) and the treatment train includes an oil grit separator, a filtering bioretention area, a sand filter or equivalent. Standard 6: Critical Areas The discharge is near or to a critical area and the treatment train includes only BMPs that MassDEP has approved for stormwater discharges to or near that particular class of critical area. Critical areas and BMPs are identified in the Stormwater Report.

283600swcheck.doc • 04/01/08

Stormwater Report Checklist • Page 6 of 8

Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program

Checklist for Stormwater Report Checklist (continued) Standard 7: Redevelopments and Other Projects Subject to the Standards only to the maximum extent practicable The project is subject to the Stormwater Management Standards only to the maximum Extent Practicable as a: Limited Project Small Residential Projects: 5-9 single family houses or 5-9 units in a multi-family development provided there is no discharge that may potentially affect a critical area. Small Residential Projects: 2-4 single family houses or 2-4 units in a multi-family development with a discharge to a critical area Marina and/or boatyard provided the hull painting, service and maintenance areas are protected from exposure to rain, snow, snow melt and runoff Bike Path and/or Foot Path Redevelopment Project Redevelopment portion of mix of new and redevelopment. Certain standards are not fully met (Standard No. 1, 8, 9, and 10 must always be fully met) and an explanation of why these standards are not met is contained in the Stormwater Report. The project involves redevelopment and a description of all measures that have been taken to improve existing conditions is provided in the Stormwater Report. The redevelopment checklist found in Volume 2 Chapter 3 of the Massachusetts Stormwater Handbook may be used to document that the proposed stormwater management system (a) complies with Standards 2, 3 and the pretreatment and structural BMP requirements of Standards 4-6 to the maximum extent practicable and (b) improves existing conditions. Standard 8: Construction Period Pollution Prevention and Erosion and Sedimentation Control A Construction Period Pollution Prevention and Erosion and Sedimentation Control Plan must include the following information: • • • • • • • • • • • • • •

Narrative; Construction Period Operation and Maintenance Plan; Names of Persons or Entity Responsible for Plan Compliance; Construction Period Pollution Prevention Measures; Erosion and Sedimentation Control Plan Drawings; Detail drawings and specifications for erosion control BMPs, including sizing calculations; Vegetation Planning; Site Development Plan; Construction Sequencing Plan; Sequencing of Erosion and Sedimentation Controls; Operation and Maintenance of Erosion and Sedimentation Controls; Inspection Schedule; Maintenance Schedule; Inspection and Maintenance Log Form.

A Construction Period Pollution Prevention and Erosion and Sedimentation Control Plan containing the information set forth above has been included in the Stormwater Report.

283600swcheck.doc • 04/01/08

Stormwater Report Checklist • Page 7 of 8

Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program

Checklist for Stormwater Report Checklist (continued) Standard 8: Construction Period Pollution Prevention and Erosion and Sedimentation Control (continued) The project is highly complex and information is included in the Stormwater Report that explains why it is not possible to submit the Construction Period Pollution Prevention and Erosion and Sedimentation Control Plan with the application. A Construction Period Pollution Prevention and Erosion and Sedimentation Control has not been included in the Stormwater Report but will be submitted before land disturbance begins. The project is not covered by a NPDES Construction General Permit. The project is covered by a NPDES Construction General Permit and a copy of the SWPPP is in the Stormwater Report. The project is covered by a NPDES Construction General Permit but no SWPPP been submitted. The SWPPP will be submitted BEFORE land disturbance begins. Standard 9: Operation and Maintenance Plan The Post Construction Operation and Maintenance Plan is included in the Stormwater Report and includes the following information: Name of the stormwater management system owners; Party responsible for operation and maintenance; Schedule for implementation of routine and non-routine maintenance tasks; Plan showing the location of all stormwater BMPs maintenance access areas; Description and delineation of public safety features; Estimated operation and maintenance budget; and Operation and Maintenance Log Form. The responsible party is not the owner of the parcel where the BMP is located and the Stormwater Report includes the following submissions: A copy of the legal instrument (deed, homeowner’s association, utility trust or other legal entity) that establishes the terms of and legal responsibility for the operation and maintenance of the project site stormwater BMPs; A plan and easement deed that allows site access for the legal entity to operate and maintain BMP functions. Standard 10: Prohibition of Illicit Discharges The Long-Term Pollution Prevention Plan includes measures to prevent illicit discharges; An Illicit Discharge Compliance Statement is attached; NO Illicit Discharge Compliance Statement is attached but will be submitted prior to the discharge of any stormwater to post-construction BMPs.

283600swcheck.doc • 04/01/08

Stormwater Report Checklist • Page 8 of 8

Appendix A Soil Data

290600

290700

290800

290900

291000

291100

291200

291300

291400

291500

291600 4676200

290500

71° 31' 26'' W

71° 32' 16'' W

Hydrologic Soil Group—Middlesex County, Massachusetts (2836.00)

42° 12' 37'' N

4674800

4674800

4674900

4674900

4675000

4675000

4675100

4675100

4675200

4675200

4675300

4675300

4675400

4675400

4675500

4675500

4675600

4675600

4675700

4675700

4675800

4675800

4675900

4675900

4676000

4676000

4676100

4676100

4676200

42° 12' 37'' N

4674700

Soil Map may not be valid at this scale.

42° 11' 47'' N

290600

290700

290800

290900

291000

291100

291200

Map Scale: 1:7,480 if printed on A portrait (8.5" x 11") sheet.

N

Meters 600 Feet 0 350 700 1400 2100 Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 19N WGS84 0

100

Natural Resources Conservation Service

200

400

Web Soil Survey National Cooperative Soil Survey

291300

291400

291500

291600 71° 31' 26'' W

71° 32' 16'' W

290500

1/6/2017 Page 1 of 5

42° 11' 47'' N

Hydrologic Soil Group—Middlesex County, Massachusetts (2836.00)

MAP LEGEND Area of Interest (AOI) Area of Interest (AOI) Soils Soil Rating Polygons A A/D B B/D C C/D D Not rated or not available Soil Rating Lines A

MAP INFORMATION The soil surveys that comprise your AOI were mapped at 1:25,000.

C C/D D

Warning: Soil Map may not be valid at this scale.

Not rated or not available

Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale.

Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography

A/D B

Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below.

B/D

Soil Survey Area: Middlesex County, Massachusetts Survey Area Data: Version 16, Sep 14, 2016

C C/D

Soil map units are labeled (as space allows) for map scales 1:50,000 or larger.

D

Date(s) aerial images were photographed: 28, 2014

Not rated or not available Soil Rating Points

Sep 12, 2014—Sep

The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident.

A A/D B B/D

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

1/6/2017 Page 2 of 5

Hydrologic Soil Group—Middlesex County, Massachusetts

2836.00

Hydrologic Soil Group

Hydrologic Soil Group— Summary by Map Unit — Middlesex County, Massachusetts (MA017) Map unit symbol

Map unit name

Rating

51A

Swansea muck, 0 to 1 percent slopes

B/D

71B

Ridgebury fine sandy loam, 3 to 8 percent slopes, extremely stony

73B

Acres in AOI

Percent of AOI 4.2

1.6%

D

20.6

7.9%

Whitman fine sandy loam, 0 to 3 percent slopes, extremely stony

D

27.3

10.5%

106C

Narragansett-HollisRock outcrop complex, 3 to 15 percent slopes

A

9.9

3.8%

302B

Montauk fine sandy loam, 0 to 8 percent slopes, extremely stony

C

0.4

0.1%

302D

Montauk fine sandy C loam, 15 to 35 percent slopes, extremely stony

5.0

1.9%

307B

Paxton fine sandy loam, C 0 to 8 percent slopes, extremely stony

15.2

5.9%

307C

Paxton fine sandy loam, C 8 to 15 percent slopes, extremely stony

1.7

0.6%

317B

Scituate fine sandy loam, 3 to 8 percent slopes, extremely stony

11.7

4.5%

336B

Rainbow silt loam, 3 to 8 C/D percent slopes, very stony

1.6

0.6%

416B

Narragansett silt loam, 3 A to 8 percent slopes, very stony

31.9

12.3%

416C

Narragansett silt loam, 8 A to 15 percent slopes, very stony

56.9

21.9%

422B

Canton fine sandy loam, B 0 to 8 percent slopes, extremely stony

41.3

15.9%

Natural Resources Conservation Service

D

Web Soil Survey National Cooperative Soil Survey

1/6/2017 Page 3 of 5

Hydrologic Soil Group—Middlesex County, Massachusetts

2836.00

Hydrologic Soil Group— Summary by Map Unit — Middlesex County, Massachusetts (MA017) Map unit symbol

Map unit name

Rating

Acres in AOI

Percent of AOI

424B

Canton fine sandy loam, A 3 to 8 percent slopes, extremely bouldery

16.8

6.5%

424C

Canton fine sandy loam, A 8 to 15 percent slopes, extremely bouldery

8.3

3.2%

424D

Canton fine sandy loam, A 15 to 25 percent slopes, extremely bouldery

6.9

2.7%

654

Udorthents, loamy

0.1

0.0%

259.7

100.0%

Totals for Area of Interest

Description Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long-duration storms. The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (A/D, B/D, and C/D). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink-swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes.

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

1/6/2017 Page 4 of 5

Appendix B Pre-Development Hydrologic Analysis

Extreme Precipitation Tables: 42.201°N, 71.531°W

Page 1 of 1

Extreme Precipitation Tables Northeast Regional Climate Center Data represents point estimates calculated from partial duration series. All precipitation amounts are displayed in inches. Smoothing State Location Longitude Latitude Elevation Date/Time

Yes Massachusetts 71.531 degrees West 42.201 degrees North 0 feet Thu, 23 Mar 2017 17:26:16 -0400

Extreme Precipitation Estimates 1yr 2yr 5yr 10yr 25yr 50yr 100yr 200yr 500yr

5min 0.29 0.35 0.42 0.47 0.56 0.63 0.72 0.82 0.99

10min 0.44 0.54 0.65 0.74 0.89 1.01 1.17 1.34 1.63

15min 0.54 0.67 0.81 0.93 1.13 1.29 1.51 1.74 2.13

30min 0.71 0.89 1.09 1.27 1.55 1.81 2.13 2.49 3.09

60min 120min 1hr 2hr 3hr 6hr 12hr 24hr 48hr 0.89 1.13 1yr 0.77 1.07 1.31 1.65 2.10 2.68 2.92 1yr 1.11 1.40 2yr 0.96 1.29 1.63 2.04 2.57 3.23 3.52 2yr 1.39 1.77 5yr 1.20 1.61 2.06 2.59 3.24 4.06 4.48 5yr 1.65 2.11 10yr 1.42 1.90 2.46 3.10 3.88 4.84 5.38 10yr 2.06 2.66 25yr 1.78 2.36 3.11 3.93 4.91 6.09 6.87 25yr 2.44 3.19 50yr 2.11 2.79 3.74 4.72 5.88 7.26 8.26 50yr 2.90 3.80 100yr 2.50 3.30 4.47 5.64 7.02 8.66 9.95 100yr 3.44 4.54 200yr 2.97 3.90 5.35 6.76 8.40 10.32 11.98 200yr 4.32 5.75 500yr 3.73 4.87 6.79 8.58 10.65 13.04 15.32 500yr

1day 2.37 2.86 3.59 4.28 5.39 6.42 7.66 9.14 11.54

2day 2.81 3.38 4.31 5.18 6.60 7.95 9.56 11.52 14.73

4day 3.25 3.89 4.93 5.91 7.50 8.99 10.79 12.94 16.47

7day 3.92 4.62 5.83 6.95 8.78 10.47 12.50 14.93 18.89

10day 4.56 5.25 6.52 7.68 9.54 11.26 13.28 15.67 19.51

1yr 2yr 5yr 10yr 25yr 50yr 100yr 200yr 500yr

Lower Confidence Limits 1yr 2yr 5yr 10yr 25yr 50yr 100yr 200yr 500yr

5min 0.23 0.34 0.38 0.42 0.49 0.54 0.59 0.66 0.75

10min 0.35 0.53 0.59 0.65 0.74 0.82 0.90 0.99 1.12

15min 0.43 0.65 0.73 0.81 0.92 1.02 1.13 1.25 1.44

30min 0.58 0.88 1.00 1.13 1.31 1.46 1.63 1.81 2.09

60min 120min 1hr 2hr 3hr 6hr 12hr 24hr 48hr 0.71 0.94 1yr 0.61 0.92 1.07 1.42 1.85 2.35 2.70 1yr 1.08 1.27 2yr 0.93 1.24 1.45 1.91 2.44 3.13 3.40 2yr 1.28 1.52 5yr 1.10 1.48 1.72 2.25 2.86 3.73 4.12 5yr 1.45 1.73 10yr 1.26 1.69 1.95 2.55 3.22 4.27 4.76 10yr 1.73 2.05 25yr 1.49 2.01 2.31 3.02 3.78 5.11 5.72 25yr 1.97 2.33 50yr 1.70 2.28 2.62 3.42 4.26 5.85 6.59 50yr 2.23 2.65 100yr 1.93 2.59 2.97 3.88 4.81 6.71 7.57 100yr 2.53 3.02 200yr 2.18 2.96 3.38 4.42 5.44 7.70 8.68 200yr 2.97 3.60 500yr 2.56 3.52 3.99 5.25 6.42 9.26 10.39 500yr

1day 2.08 2.77 3.31 3.78 4.53 5.18 5.94 6.81 8.19

2day 2.60 3.27 3.97 4.57 5.50 6.34 7.28 8.35 9.99

4day 2.95 3.76 4.54 5.24 6.34 7.33 8.48 9.80 11.90

7day 3.58 4.46 5.36 6.14 7.36 8.43 9.70 11.14 13.38

10day 4.11 5.08 6.02 6.84 8.07 9.18 10.44 11.89 14.14

1yr 2yr 5yr 10yr 25yr 50yr 100yr 200yr 500yr

Upper Confidence Limits 1yr 2yr 5yr 10yr 25yr 50yr 100yr 200yr 500yr

5min 0.32 0.37 0.45 0.54 0.69 0.82 0.99 1.19 1.55

10min 0.49 0.56 0.70 0.83 1.04 1.25 1.50 1.80 2.30

15min 0.60 0.69 0.87 1.03 1.30 1.56 1.88 2.28 2.96

30min 0.81 0.94 1.19 1.44 1.86 2.24 2.71 3.30 4.30

60min 120min 1hr 2hr 3hr 6hr 12hr 24hr 48hr 1.00 1.19 1yr 0.86 1.17 1.37 1.76 2.30 2.93 3.16 1yr 1.16 1.36 2yr 1.00 1.33 1.57 2.04 2.60 3.36 3.66 2yr 1.51 1.78 5yr 1.31 1.74 2.04 2.62 3.31 4.39 4.86 5yr 1.86 2.19 10yr 1.60 2.14 2.50 3.18 3.96 5.39 6.06 10yr 2.44 2.88 25yr 2.11 2.82 3.27 4.08 5.05 7.07 8.12 25yr 3.01 3.54 50yr 2.60 3.46 4.02 4.94 6.06 8.69 10.12 50yr 3.72 4.36 100yr 3.21 4.26 4.93 5.98 7.28 10.67 12.66 100yr 4.60 5.37 200yr 3.97 5.25 6.07 7.24 8.73 13.10 15.85 200yr 6.11 7.08 500yr 5.28 6.92 7.98 9.32 11.12 17.21 21.36 500yr

1day 2.60 2.97 3.89 4.77 6.26 7.69 9.44 11.59 15.23

2day 3.04 3.52 4.67 5.83 7.80 9.73 12.18 15.24 20.54

4day 3.53 4.05 5.37 6.65 8.85 10.98 13.64 16.93 22.55

7day 4.23 4.80 6.35 7.84 10.39 12.84 15.88 19.65 26.05

10day 4.89 5.44 7.04 8.58 11.15 13.62 16.61 20.23 26.30

1yr 2yr 5yr 10yr 25yr 50yr 100yr 200yr 500yr

Powered by ACIS

file:///G:/Projdata/2836/Transfers/In/NRCC/2017-03-23/output.htm

4/24/2017

Hydrologic Soil Group—Middlesex County, Massachusetts

2836.00

Rating Options Aggregation Method: Dominant Condition Component Percent Cutoff: None Specified Tie-break Rule: Higher

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

1/6/2017 Page 5 of 5

10R 1S E-DP-1 E-DA-1

2S 30R

3S

E-DP-3

E-DA-3

E-DA-2

20R E-DP-2

PRE-DEVELOPMENT

Subcat

Reach

Pond

Link

Routing Diagram for 283600HC001A Prepared by Microsoft, Printed 4/24/2017 HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

2836.00 Pre-Development

283600HC001A Prepared by Microsoft HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Area Listing (selected nodes) Area (acres)

CN

0.081 2.223 0.021 0.077 0.349 0.066 0.127 11.144 9.228 0.256 23.572

39 61 80 98 98 98 98 30 55 77 45

Description (subcatchment-numbers) >75% Grass cover, Good, HSG A (3S) >75% Grass cover, Good, HSG B (2S, 3S) >75% Grass cover, Good, HSG D (3S) Paved parking, HSG A (3S) Paved parking, HSG B (2S, 3S) Paved parking, HSG D (2S, 3S) Unconnected roofs, HSG B (2S, 3S) Woods, Good, HSG A (1S, 2S, 3S) Woods, Good, HSG B (1S, 2S, 3S) Woods, Good, HSG D (1S, 2S, 3S) TOTAL AREA

Printed 4/24/2017 Page 2

2836.00 Pre-Development

283600HC001A Prepared by Microsoft HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Soil Listing (selected nodes) Area (acres)

Soil Group

Subcatchment Numbers

11.302 11.927 0.000 0.343 0.000 23.572

HSG A HSG B HSG C HSG D Other

1S, 2S, 3S 1S, 2S, 3S 1S, 2S, 3S TOTAL AREA

Printed 4/24/2017 Page 3

2836.00 Pre-Development

283600HC001A Printed 4/24/2017 Page 4

Prepared by Microsoft HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Ground Covers (selected nodes) HSG-A (acres)

HSG-B (acres)

HSG-C (acres)

HSG-D (acres)

Other (acres)

Total (acres)

Ground Cover

Subcatchment Numbers

0.081 0.077 0.000 11.144

2.223 0.349 0.127 9.228

0.000 0.000 0.000 0.000

0.021 0.066 0.000 0.256

0.000 0.000 0.000 0.000

2.325 0.492 0.127 20.628

>75% Grass cover, Good Paved parking Unconnected roofs Woods, Good

2S, 3S 2S, 3S 2S, 3S 1S, 2S, 3S

11.302

11.927

0.000

0.343

0.000

23.572

TOTAL AREA

2836.00 Pre-Development

Type III 24-hr 2-YR NRCC Rainfall=3.22"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Printed 4/24/2017 Page 5

Summary for Subcatchment 1S: E-DA-1 [45] Hint: Runoff=Zero Runoff

=

0.00 cfs @

0.00 hrs, Volume=

0.000 af, Depth= 0.00"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2-YR NRCC Rainfall=3.22" Area (ac) 7.407 1.544 0.001 8.952 8.952

CN 30 55 77 34

Description Woods, Good, HSG A Woods, Good, HSG B Woods, Good, HSG D Weighted Average 100.00% Pervious Area

Tc Length Slope (min) (feet) (ft/ft) 13.0 50 0.0690

Velocity (ft/sec) 0.06

11.9

272

0.0231

0.38

6.4

308

0.1045

0.81

31.3

630

Total

Capacity (cfs)

Description Sheet Flow, Sheet Flow Woods: Dense underbrush n= 0.800 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Forest w/Heavy Litter Kv= 2.5 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Forest w/Heavy Litter Kv= 2.5 fps

Summary for Subcatchment 2S: E-DA-2 Runoff

=

0.22 cfs @ 12.95 hrs, Volume=

0.093 af, Depth> 0.17"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2-YR NRCC Rainfall=3.22" Area (ac) 0.105 0.053 0.056 1.417 3.482 0.057 1.229 6.399 6.185 0.214 0.056

CN 98 98 98 30 55 77 61 52

Description Paved parking, HSG B Paved parking, HSG D Unconnected roofs, HSG B Woods, Good, HSG A Woods, Good, HSG B Woods, Good, HSG D >75% Grass cover, Good, HSG B Weighted Average 96.66% Pervious Area 3.34% Impervious Area 26.17% Unconnected

2836.00 Pre-Development

Type III 24-hr 2-YR NRCC Rainfall=3.22"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Tc Length Slope (min) (feet) (ft/ft) 15.5 50 0.0450

Velocity (ft/sec) 0.05

13.2

299

0.0229

0.38

3.6

168

0.0954

0.77

5.8

165

0.0364

0.48

38.1

682

Total

Capacity (cfs)

Printed 4/24/2017 Page 6

Description Sheet Flow, Sheet Flow Woods: Dense underbrush n= 0.800 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Forest w/Heavy Litter Kv= 2.5 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Forest w/Heavy Litter Kv= 2.5 fps Shallow Concentrated Flow, Shallow Concentrated Flow 3 Forest w/Heavy Litter Kv= 2.5 fps

Summary for Subcatchment 3S: E-DA-3 Runoff

=

0.22 cfs @ 12.97 hrs, Volume=

0.104 af, Depth> 0.15"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2-YR NRCC Rainfall=3.22" Area (ac) 0.077 0.244 0.013 0.071 2.320 4.202 0.198 0.081 0.994 0.021 8.221 7.816 0.405 0.071

CN 98 98 98 98 30 55 77 39 61 80 51

Description Paved parking, HSG A Paved parking, HSG B Paved parking, HSG D Unconnected roofs, HSG B Woods, Good, HSG A Woods, Good, HSG B Woods, Good, HSG D >75% Grass cover, Good, HSG A >75% Grass cover, Good, HSG B >75% Grass cover, Good, HSG D Weighted Average 95.07% Pervious Area 4.93% Impervious Area 17.53% Unconnected

Tc Length Slope (min) (feet) (ft/ft) 14.8 50 0.0500

Velocity (ft/sec) 0.06

12.1

347

0.0363

0.48

7.0

301

0.0830

0.72

33.9

698

Total

Capacity (cfs)

Description Sheet Flow, Sheet Flow Woods: Dense underbrush n= 0.800 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Forest w/Heavy Litter Kv= 2.5 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Forest w/Heavy Litter Kv= 2.5 fps

2836.00 Pre-Development

Type III 24-hr 2-YR NRCC Rainfall=3.22"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Printed 4/24/2017 Page 7

Summary for Reach 10R: E-DP-1 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = Inflow = Outflow =

8.952 ac, 0.00% Impervious, Inflow Depth = 0.00" for 2-YR NRCC event 0.00 cfs @ 0.00 hrs, Volume= 0.000 af 0.00 cfs @ 0.00 hrs, Volume= 0.000 af, Atten= 0%, Lag= 0.0 min

Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs

Summary for Reach 20R: E-DP-2 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = Inflow = Outflow =

6.399 ac, 3.34% Impervious, Inflow Depth > 0.17" for 2-YR NRCC event 0.22 cfs @ 12.95 hrs, Volume= 0.093 af 0.22 cfs @ 12.95 hrs, Volume= 0.093 af, Atten= 0%, Lag= 0.0 min

Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs

Summary for Reach 30R: E-DP-3 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = Inflow = Outflow =

8.221 ac, 4.93% Impervious, Inflow Depth > 0.15" for 2-YR NRCC event 0.22 cfs @ 12.97 hrs, Volume= 0.104 af 0.22 cfs @ 12.97 hrs, Volume= 0.104 af, Atten= 0%, Lag= 0.0 min

Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs

2836.00 Pre-Development

Type III 24-hr 10-YR NRCC Rainfall=4.81"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Printed 4/24/2017 Page 8

Summary for Subcatchment 1S: E-DA-1 Runoff

=

0.04 cfs @ 17.18 hrs, Volume=

0.030 af, Depth> 0.04"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10-YR NRCC Rainfall=4.81" Area (ac) 7.407 1.544 0.001 8.952 8.952

CN 30 55 77 34

Description Woods, Good, HSG A Woods, Good, HSG B Woods, Good, HSG D Weighted Average 100.00% Pervious Area

Tc Length Slope (min) (feet) (ft/ft) 13.0 50 0.0690

Velocity (ft/sec) 0.06

11.9

272

0.0231

0.38

6.4

308

0.1045

0.81

31.3

630

Total

Capacity (cfs)

Description Sheet Flow, Sheet Flow Woods: Dense underbrush n= 0.800 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Forest w/Heavy Litter Kv= 2.5 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Forest w/Heavy Litter Kv= 2.5 fps

Summary for Subcatchment 2S: E-DA-2 Runoff

=

1.95 cfs @ 12.67 hrs, Volume=

0.379 af, Depth> 0.71"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10-YR NRCC Rainfall=4.81" Area (ac) 0.105 0.053 0.056 1.417 3.482 0.057 1.229 6.399 6.185 0.214 0.056

CN 98 98 98 30 55 77 61 52

Description Paved parking, HSG B Paved parking, HSG D Unconnected roofs, HSG B Woods, Good, HSG A Woods, Good, HSG B Woods, Good, HSG D >75% Grass cover, Good, HSG B Weighted Average 96.66% Pervious Area 3.34% Impervious Area 26.17% Unconnected

2836.00 Pre-Development

Type III 24-hr 10-YR NRCC Rainfall=4.81"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Tc Length Slope (min) (feet) (ft/ft) 15.5 50 0.0450

Velocity (ft/sec) 0.05

13.2

299

0.0229

0.38

3.6

168

0.0954

0.77

5.8

165

0.0364

0.48

38.1

682

Total

Capacity (cfs)

Printed 4/24/2017 Page 9

Description Sheet Flow, Sheet Flow Woods: Dense underbrush n= 0.800 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Forest w/Heavy Litter Kv= 2.5 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Forest w/Heavy Litter Kv= 2.5 fps Shallow Concentrated Flow, Shallow Concentrated Flow 3 Forest w/Heavy Litter Kv= 2.5 fps

Summary for Subcatchment 3S: E-DA-3 Runoff

=

2.35 cfs @ 12.62 hrs, Volume=

0.451 af, Depth> 0.66"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10-YR NRCC Rainfall=4.81" Area (ac) 0.077 0.244 0.013 0.071 2.320 4.202 0.198 0.081 0.994 0.021 8.221 7.816 0.405 0.071

CN 98 98 98 98 30 55 77 39 61 80 51

Description Paved parking, HSG A Paved parking, HSG B Paved parking, HSG D Unconnected roofs, HSG B Woods, Good, HSG A Woods, Good, HSG B Woods, Good, HSG D >75% Grass cover, Good, HSG A >75% Grass cover, Good, HSG B >75% Grass cover, Good, HSG D Weighted Average 95.07% Pervious Area 4.93% Impervious Area 17.53% Unconnected

Tc Length Slope (min) (feet) (ft/ft) 14.8 50 0.0500

Velocity (ft/sec) 0.06

12.1

347

0.0363

0.48

7.0

301

0.0830

0.72

33.9

698

Total

Capacity (cfs)

Description Sheet Flow, Sheet Flow Woods: Dense underbrush n= 0.800 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Forest w/Heavy Litter Kv= 2.5 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Forest w/Heavy Litter Kv= 2.5 fps

2836.00 Pre-Development

Type III 24-hr 10-YR NRCC Rainfall=4.81"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Printed 4/24/2017 Page 10

Summary for Reach 10R: E-DP-1 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = Inflow = Outflow =

8.952 ac, 0.00% Impervious, Inflow Depth > 0.04" for 10-YR NRCC event 0.04 cfs @ 17.18 hrs, Volume= 0.030 af 0.04 cfs @ 17.18 hrs, Volume= 0.030 af, Atten= 0%, Lag= 0.0 min

Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs

Summary for Reach 20R: E-DP-2 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = Inflow = Outflow =

6.399 ac, 3.34% Impervious, Inflow Depth > 0.71" for 10-YR NRCC event 1.95 cfs @ 12.67 hrs, Volume= 0.379 af 1.95 cfs @ 12.67 hrs, Volume= 0.379 af, Atten= 0%, Lag= 0.0 min

Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs

Summary for Reach 30R: E-DP-3 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = Inflow = Outflow =

8.221 ac, 4.93% Impervious, Inflow Depth > 0.66" for 10-YR NRCC event 2.35 cfs @ 12.62 hrs, Volume= 0.451 af 2.35 cfs @ 12.62 hrs, Volume= 0.451 af, Atten= 0%, Lag= 0.0 min

Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs

2836.00 Pre-Development

Type III 24-hr 25-YR NRCC Rainfall=6.05"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Printed 4/24/2017 Page 11

Summary for Subcatchment 1S: E-DA-1 Runoff

=

0.27 cfs @ 13.97 hrs, Volume=

0.159 af, Depth> 0.21"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 25-YR NRCC Rainfall=6.05" Area (ac) 7.407 1.544 0.001 8.952 8.952

CN 30 55 77 34

Description Woods, Good, HSG A Woods, Good, HSG B Woods, Good, HSG D Weighted Average 100.00% Pervious Area

Tc Length Slope (min) (feet) (ft/ft) 13.0 50 0.0690

Velocity (ft/sec) 0.06

11.9

272

0.0231

0.38

6.4

308

0.1045

0.81

31.3

630

Total

Capacity (cfs)

Description Sheet Flow, Sheet Flow Woods: Dense underbrush n= 0.800 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Forest w/Heavy Litter Kv= 2.5 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Forest w/Heavy Litter Kv= 2.5 fps

Summary for Subcatchment 2S: E-DA-2 Runoff

=

4.21 cfs @ 12.62 hrs, Volume=

0.693 af, Depth> 1.30"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 25-YR NRCC Rainfall=6.05" Area (ac) 0.105 0.053 0.056 1.417 3.482 0.057 1.229 6.399 6.185 0.214 0.056

CN 98 98 98 30 55 77 61 52

Description Paved parking, HSG B Paved parking, HSG D Unconnected roofs, HSG B Woods, Good, HSG A Woods, Good, HSG B Woods, Good, HSG D >75% Grass cover, Good, HSG B Weighted Average 96.66% Pervious Area 3.34% Impervious Area 26.17% Unconnected

2836.00 Pre-Development

Type III 24-hr 25-YR NRCC Rainfall=6.05"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Tc Length Slope (min) (feet) (ft/ft) 15.5 50 0.0450

Velocity (ft/sec) 0.05

13.2

299

0.0229

0.38

3.6

168

0.0954

0.77

5.8

165

0.0364

0.48

38.1

682

Total

Capacity (cfs)

Printed 4/24/2017 Page 12

Description Sheet Flow, Sheet Flow Woods: Dense underbrush n= 0.800 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Forest w/Heavy Litter Kv= 2.5 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Forest w/Heavy Litter Kv= 2.5 fps Shallow Concentrated Flow, Shallow Concentrated Flow 3 Forest w/Heavy Litter Kv= 2.5 fps

Summary for Subcatchment 3S: E-DA-3 Runoff

=

5.29 cfs @ 12.56 hrs, Volume=

0.841 af, Depth> 1.23"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 25-YR NRCC Rainfall=6.05" Area (ac) 0.077 0.244 0.013 0.071 2.320 4.202 0.198 0.081 0.994 0.021 8.221 7.816 0.405 0.071

CN 98 98 98 98 30 55 77 39 61 80 51

Description Paved parking, HSG A Paved parking, HSG B Paved parking, HSG D Unconnected roofs, HSG B Woods, Good, HSG A Woods, Good, HSG B Woods, Good, HSG D >75% Grass cover, Good, HSG A >75% Grass cover, Good, HSG B >75% Grass cover, Good, HSG D Weighted Average 95.07% Pervious Area 4.93% Impervious Area 17.53% Unconnected

Tc Length Slope (min) (feet) (ft/ft) 14.8 50 0.0500

Velocity (ft/sec) 0.06

12.1

347

0.0363

0.48

7.0

301

0.0830

0.72

33.9

698

Total

Capacity (cfs)

Description Sheet Flow, Sheet Flow Woods: Dense underbrush n= 0.800 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Forest w/Heavy Litter Kv= 2.5 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Forest w/Heavy Litter Kv= 2.5 fps

2836.00 Pre-Development

Type III 24-hr 25-YR NRCC Rainfall=6.05"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Printed 4/24/2017 Page 13

Summary for Reach 10R: E-DP-1 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = Inflow = Outflow =

8.952 ac, 0.00% Impervious, Inflow Depth > 0.21" for 25-YR NRCC event 0.27 cfs @ 13.97 hrs, Volume= 0.159 af 0.27 cfs @ 13.97 hrs, Volume= 0.159 af, Atten= 0%, Lag= 0.0 min

Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs

Summary for Reach 20R: E-DP-2 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = Inflow = Outflow =

6.399 ac, 3.34% Impervious, Inflow Depth > 1.30" for 25-YR NRCC event 4.21 cfs @ 12.62 hrs, Volume= 0.693 af 4.21 cfs @ 12.62 hrs, Volume= 0.693 af, Atten= 0%, Lag= 0.0 min

Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs

Summary for Reach 30R: E-DP-3 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = Inflow = Outflow =

8.221 ac, 4.93% Impervious, Inflow Depth > 1.23" for 25-YR NRCC event 5.29 cfs @ 12.56 hrs, Volume= 0.841 af 5.29 cfs @ 12.56 hrs, Volume= 0.841 af, Atten= 0%, Lag= 0.0 min

Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs

2836.00 Pre-Development

Type III 24-hr 100-YR NRCC Rainfall=8.59"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Printed 4/24/2017 Page 14

Summary for Subcatchment 1S: E-DA-1 Runoff

=

3.08 cfs @ 12.64 hrs, Volume=

0.676 af, Depth> 0.91"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100-YR NRCC Rainfall=8.59" Area (ac) 7.407 1.544 0.001 8.952 8.952

CN 30 55 77 34

Description Woods, Good, HSG A Woods, Good, HSG B Woods, Good, HSG D Weighted Average 100.00% Pervious Area

Tc Length Slope (min) (feet) (ft/ft) 13.0 50 0.0690

Velocity (ft/sec) 0.06

11.9

272

0.0231

0.38

6.4

308

0.1045

0.81

31.3

630

Total

Capacity (cfs)

Description Sheet Flow, Sheet Flow Woods: Dense underbrush n= 0.800 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Forest w/Heavy Litter Kv= 2.5 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Forest w/Heavy Litter Kv= 2.5 fps

Summary for Subcatchment 2S: E-DA-2 Runoff

=

10.21 cfs @ 12.57 hrs, Volume=

1.503 af, Depth> 2.82"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100-YR NRCC Rainfall=8.59" Area (ac) 0.105 0.053 0.056 1.417 3.482 0.057 1.229 6.399 6.185 0.214 0.056

CN 98 98 98 30 55 77 61 52

Description Paved parking, HSG B Paved parking, HSG D Unconnected roofs, HSG B Woods, Good, HSG A Woods, Good, HSG B Woods, Good, HSG D >75% Grass cover, Good, HSG B Weighted Average 96.66% Pervious Area 3.34% Impervious Area 26.17% Unconnected

2836.00 Pre-Development

Type III 24-hr 100-YR NRCC Rainfall=8.59"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Tc Length Slope (min) (feet) (ft/ft) 15.5 50 0.0450

Velocity (ft/sec) 0.05

13.2

299

0.0229

0.38

3.6

168

0.0954

0.77

5.8

165

0.0364

0.48

38.1

682

Total

Capacity (cfs)

Printed 4/24/2017 Page 15

Description Sheet Flow, Sheet Flow Woods: Dense underbrush n= 0.800 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Forest w/Heavy Litter Kv= 2.5 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Forest w/Heavy Litter Kv= 2.5 fps Shallow Concentrated Flow, Shallow Concentrated Flow 3 Forest w/Heavy Litter Kv= 2.5 fps

Summary for Subcatchment 3S: E-DA-3 Runoff

=

13.23 cfs @ 12.52 hrs, Volume=

1.855 af, Depth> 2.71"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100-YR NRCC Rainfall=8.59" Area (ac) 0.077 0.244 0.013 0.071 2.320 4.202 0.198 0.081 0.994 0.021 8.221 7.816 0.405 0.071

CN 98 98 98 98 30 55 77 39 61 80 51

Description Paved parking, HSG A Paved parking, HSG B Paved parking, HSG D Unconnected roofs, HSG B Woods, Good, HSG A Woods, Good, HSG B Woods, Good, HSG D >75% Grass cover, Good, HSG A >75% Grass cover, Good, HSG B >75% Grass cover, Good, HSG D Weighted Average 95.07% Pervious Area 4.93% Impervious Area 17.53% Unconnected

Tc Length Slope (min) (feet) (ft/ft) 14.8 50 0.0500

Velocity (ft/sec) 0.06

12.1

347

0.0363

0.48

7.0

301

0.0830

0.72

33.9

698

Total

Capacity (cfs)

Description Sheet Flow, Sheet Flow Woods: Dense underbrush n= 0.800 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Forest w/Heavy Litter Kv= 2.5 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Forest w/Heavy Litter Kv= 2.5 fps

2836.00 Pre-Development

Type III 24-hr 100-YR NRCC Rainfall=8.59"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Printed 4/24/2017 Page 16

Summary for Reach 10R: E-DP-1 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = Inflow = Outflow =

8.952 ac, 0.00% Impervious, Inflow Depth > 0.91" for 100-YR NRCC event 3.08 cfs @ 12.64 hrs, Volume= 0.676 af 3.08 cfs @ 12.64 hrs, Volume= 0.676 af, Atten= 0%, Lag= 0.0 min

Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs

Summary for Reach 20R: E-DP-2 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = Inflow = Outflow =

6.399 ac, 3.34% Impervious, Inflow Depth > 2.82" for 100-YR NRCC event 10.21 cfs @ 12.57 hrs, Volume= 1.503 af 10.21 cfs @ 12.57 hrs, Volume= 1.503 af, Atten= 0%, Lag= 0.0 min

Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs

Summary for Reach 30R: E-DP-3 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = Inflow = Outflow =

8.221 ac, 4.93% Impervious, Inflow Depth > 2.71" for 100-YR NRCC event 13.23 cfs @ 12.52 hrs, Volume= 1.855 af 13.23 cfs @ 12.52 hrs, Volume= 1.855 af, Atten= 0%, Lag= 0.0 min

Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs

Appendix C Post-Development Hydrologic Analysis

Extreme Precipitation Tables: 42.201°N, 71.531°W

Page 1 of 1

Extreme Precipitation Tables Northeast Regional Climate Center Data represents point estimates calculated from partial duration series. All precipitation amounts are displayed in inches. Smoothing State Location Longitude Latitude Elevation Date/Time

Yes Massachusetts 71.531 degrees West 42.201 degrees North 0 feet Thu, 23 Mar 2017 17:26:16 -0400

Extreme Precipitation Estimates 1yr 2yr 5yr 10yr 25yr 50yr 100yr 200yr 500yr

5min 0.29 0.35 0.42 0.47 0.56 0.63 0.72 0.82 0.99

10min 0.44 0.54 0.65 0.74 0.89 1.01 1.17 1.34 1.63

15min 0.54 0.67 0.81 0.93 1.13 1.29 1.51 1.74 2.13

30min 0.71 0.89 1.09 1.27 1.55 1.81 2.13 2.49 3.09

60min 120min 1hr 2hr 3hr 6hr 12hr 24hr 48hr 0.89 1.13 1yr 0.77 1.07 1.31 1.65 2.10 2.68 2.92 1yr 1.11 1.40 2yr 0.96 1.29 1.63 2.04 2.57 3.23 3.52 2yr 1.39 1.77 5yr 1.20 1.61 2.06 2.59 3.24 4.06 4.48 5yr 1.65 2.11 10yr 1.42 1.90 2.46 3.10 3.88 4.84 5.38 10yr 2.06 2.66 25yr 1.78 2.36 3.11 3.93 4.91 6.09 6.87 25yr 2.44 3.19 50yr 2.11 2.79 3.74 4.72 5.88 7.26 8.26 50yr 2.90 3.80 100yr 2.50 3.30 4.47 5.64 7.02 8.66 9.95 100yr 3.44 4.54 200yr 2.97 3.90 5.35 6.76 8.40 10.32 11.98 200yr 4.32 5.75 500yr 3.73 4.87 6.79 8.58 10.65 13.04 15.32 500yr

1day 2.37 2.86 3.59 4.28 5.39 6.42 7.66 9.14 11.54

2day 2.81 3.38 4.31 5.18 6.60 7.95 9.56 11.52 14.73

4day 3.25 3.89 4.93 5.91 7.50 8.99 10.79 12.94 16.47

7day 3.92 4.62 5.83 6.95 8.78 10.47 12.50 14.93 18.89

10day 4.56 5.25 6.52 7.68 9.54 11.26 13.28 15.67 19.51

1yr 2yr 5yr 10yr 25yr 50yr 100yr 200yr 500yr

Lower Confidence Limits 1yr 2yr 5yr 10yr 25yr 50yr 100yr 200yr 500yr

5min 0.23 0.34 0.38 0.42 0.49 0.54 0.59 0.66 0.75

10min 0.35 0.53 0.59 0.65 0.74 0.82 0.90 0.99 1.12

15min 0.43 0.65 0.73 0.81 0.92 1.02 1.13 1.25 1.44

30min 0.58 0.88 1.00 1.13 1.31 1.46 1.63 1.81 2.09

60min 120min 1hr 2hr 3hr 6hr 12hr 24hr 48hr 0.71 0.94 1yr 0.61 0.92 1.07 1.42 1.85 2.35 2.70 1yr 1.08 1.27 2yr 0.93 1.24 1.45 1.91 2.44 3.13 3.40 2yr 1.28 1.52 5yr 1.10 1.48 1.72 2.25 2.86 3.73 4.12 5yr 1.45 1.73 10yr 1.26 1.69 1.95 2.55 3.22 4.27 4.76 10yr 1.73 2.05 25yr 1.49 2.01 2.31 3.02 3.78 5.11 5.72 25yr 1.97 2.33 50yr 1.70 2.28 2.62 3.42 4.26 5.85 6.59 50yr 2.23 2.65 100yr 1.93 2.59 2.97 3.88 4.81 6.71 7.57 100yr 2.53 3.02 200yr 2.18 2.96 3.38 4.42 5.44 7.70 8.68 200yr 2.97 3.60 500yr 2.56 3.52 3.99 5.25 6.42 9.26 10.39 500yr

1day 2.08 2.77 3.31 3.78 4.53 5.18 5.94 6.81 8.19

2day 2.60 3.27 3.97 4.57 5.50 6.34 7.28 8.35 9.99

4day 2.95 3.76 4.54 5.24 6.34 7.33 8.48 9.80 11.90

7day 3.58 4.46 5.36 6.14 7.36 8.43 9.70 11.14 13.38

10day 4.11 5.08 6.02 6.84 8.07 9.18 10.44 11.89 14.14

1yr 2yr 5yr 10yr 25yr 50yr 100yr 200yr 500yr

Upper Confidence Limits 1yr 2yr 5yr 10yr 25yr 50yr 100yr 200yr 500yr

5min 0.32 0.37 0.45 0.54 0.69 0.82 0.99 1.19 1.55

10min 0.49 0.56 0.70 0.83 1.04 1.25 1.50 1.80 2.30

15min 0.60 0.69 0.87 1.03 1.30 1.56 1.88 2.28 2.96

30min 0.81 0.94 1.19 1.44 1.86 2.24 2.71 3.30 4.30

60min 120min 1hr 2hr 3hr 6hr 12hr 24hr 48hr 1.00 1.19 1yr 0.86 1.17 1.37 1.76 2.30 2.93 3.16 1yr 1.16 1.36 2yr 1.00 1.33 1.57 2.04 2.60 3.36 3.66 2yr 1.51 1.78 5yr 1.31 1.74 2.04 2.62 3.31 4.39 4.86 5yr 1.86 2.19 10yr 1.60 2.14 2.50 3.18 3.96 5.39 6.06 10yr 2.44 2.88 25yr 2.11 2.82 3.27 4.08 5.05 7.07 8.12 25yr 3.01 3.54 50yr 2.60 3.46 4.02 4.94 6.06 8.69 10.12 50yr 3.72 4.36 100yr 3.21 4.26 4.93 5.98 7.28 10.67 12.66 100yr 4.60 5.37 200yr 3.97 5.25 6.07 7.24 8.73 13.10 15.85 200yr 6.11 7.08 500yr 5.28 6.92 7.98 9.32 11.12 17.21 21.36 500yr

1day 2.60 2.97 3.89 4.77 6.26 7.69 9.44 11.59 15.23

2day 3.04 3.52 4.67 5.83 7.80 9.73 12.18 15.24 20.54

4day 3.53 4.05 5.37 6.65 8.85 10.98 13.64 16.93 22.55

7day 4.23 4.80 6.35 7.84 10.39 12.84 15.88 19.65 26.05

10day 4.89 5.44 7.04 8.58 11.15 13.62 16.61 20.23 26.30

1yr 2yr 5yr 10yr 25yr 50yr 100yr 200yr 500yr

Powered by ACIS

file:///G:/Projdata/2836/Transfers/In/NRCC/2017-03-23/output.htm

4/24/2017

101AS P-DA-1A

101BS

101AP

110R

P-DA-1B

BASIN-1

P-DP-1

103AS

102AS

P-DA-3A

P-DA-2A

130R

103P

103BS

102BS

102P

120R

P-DP-3

BASIN-3

P-DA-3B

P-DA-2B

BASIN-2

P-DP-2

POST-DEVELOPMENT

Subcat

Reach

Pond

Link

Routing Diagram for 283600HC001A Prepared by Microsoft, Printed 4/26/2017 HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

2836.00 Post-Development

283600HC001A Prepared by Microsoft HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Area Listing (selected nodes) Area (acres)

CN

0.074 2.231 0.021 0.300 7.166 3.970 0.078 0.252 0.013 0.113 0.129 0.053 3.974 4.892 0.316 23.582

39 61 80 96 30 58 98 98 98 98 98 98 30 55 77 46

Description (subcatchment-numbers) >75% Grass cover, Good, HSG A (103AS, 103BS) >75% Grass cover, Good, HSG B (102AS, 103AS, 103BS) >75% Grass cover, Good, HSG D (103AS) Gravel surface, HSG B (101BS, 102BS, 103BS) Meadow, non-grazed, HSG A (101AS, 101BS, 103AS, 103BS) Meadow, non-grazed, HSG B (101BS, 102AS, 102BS, 103BS) Paved parking, HSG A (103AS, 103BS) Paved parking, HSG B (103BS) Paved parking, HSG D (103AS) Unconnected pavement, HSG B (101BS, 102AS) Unconnected roofs, HSG B (102AS, 103BS) Water Surface, HSG B (102AS) Woods, Good, HSG A (101AS, 101BS, 102AS, 103AS, 103BS) Woods, Good, HSG B (101BS, 102AS, 102BS, 103AS, 103BS) Woods, Good, HSG D (101AS, 102AS, 103AS) TOTAL AREA

Printed 4/26/2017 Page 2

2836.00 Post-Development

283600HC001A Prepared by Microsoft HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Soil Listing (selected nodes) Area (acres)

Soil Group

Subcatchment Numbers

11.292 11.940 0.000 0.350 0.000 23.582

HSG A HSG B HSG C HSG D Other

101AS, 101BS, 102AS, 103AS, 103BS 101BS, 102AS, 102BS, 103AS, 103BS 101AS, 102AS, 103AS TOTAL AREA

Printed 4/26/2017 Page 3

2836.00 Post-Development

283600HC001A Printed 4/26/2017 Page 4

Prepared by Microsoft HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Ground Covers (selected nodes) HSG-A (acres)

HSG-B (acres)

HSG-C (acres)

HSG-D (acres)

Other (acres)

Total (acres)

0.074

2.231

0.000

0.021

0.000

2.326

0.000

0.300

0.000

0.000

0.000

0.300

7.166

3.970

0.000

0.000

0.000

11.136

0.078

0.252

0.000

0.013

0.000

0.343

0.000

0.113

0.000

0.000

0.000

0.113

0.000

0.129

0.000

0.000

0.000

0.129

0.000 3.974

0.053 4.892

0.000 0.000

0.000 0.316

0.000 0.000

0.053 9.182

11.292

11.940

0.000

0.350

0.000

23.582

Ground Cover

Subcatchment Numbers

>75% Grass cover, Good 102AS, 103AS, 103BS Gravel surface 101BS, 102BS, 103BS Meadow, non-grazed 101AS, 101BS, 102AS, 102BS, 103AS, 103BS Paved parking 103AS, 103BS Unconnected pavement 101BS, 102AS Unconnected roofs 102AS, 103BS Water Surface 102AS Woods, Good 101AS, 101BS, 102AS, 102BS, 103AS, 103BS TOTAL AREA

2836.00 Post-Development

Type III 24-hr 2-YR NRCC Rainfall=3.22"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Printed 4/26/2017 Page 5

Summary for Subcatchment 101AS: P-DA-1A [45] Hint: Runoff=Zero Runoff

=

0.00 cfs @

0.00 hrs, Volume=

0.000 af, Depth= 0.00"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2-YR NRCC Rainfall=3.22" Area (ac) 1.479 0.001 0.403 1.883 1.883

CN 30 77 30 30

Tc Length (min) (feet) 6.0

Description Woods, Good, HSG A Woods, Good, HSG D Meadow, non-grazed, HSG A Weighted Average 100.00% Pervious Area Slope (ft/ft)

Velocity (ft/sec)

Capacity (cfs)

Description Direct Entry, Minimum

Summary for Subcatchment 101BS: P-DA-1B [45] Hint: Runoff=Zero Runoff

=

0.00 cfs @

0.00 hrs, Volume=

0.000 af, Depth= 0.00"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2-YR NRCC Rainfall=3.22" Area (ac) 0.452 2.021 5.336 0.363 0.008 0.051 8.231 8.223 0.008 0.008

CN 30 55 30 58 98 96 38

Description Woods, Good, HSG A Woods, Good, HSG B Meadow, non-grazed, HSG A Meadow, non-grazed, HSG B Unconnected pavement, HSG B Gravel surface, HSG B Weighted Average 99.90% Pervious Area 0.10% Impervious Area 100.00% Unconnected

Tc Length Slope (min) (feet) (ft/ft) 13.0 50 0.0690

Velocity (ft/sec) 0.06

12.8

292

0.0231

0.38

5.4

260

0.1045

0.81

31.2

602

Total

Capacity (cfs)

Description Sheet Flow, Sheet Flow Woods: Dense underbrush n= 0.800 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Forest w/Heavy Litter Kv= 2.5 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Forest w/Heavy Litter Kv= 2.5 fps

2836.00 Post-Development

Type III 24-hr 2-YR NRCC Rainfall=3.22"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Printed 4/26/2017 Page 6

Summary for Subcatchment 102AS: P-DA-2A Runoff

=

0.19 cfs @ 12.49 hrs, Volume=

0.057 af, Depth> 0.18"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2-YR NRCC Rainfall=3.22" Area (ac) 0.105 0.053 0.057 1.156 0.773 0.117 1.205 0.432 3.898 3.683 0.215 0.162

CN 98 98 98 30 55 77 61 58 53

Adj

52

Tc Length Slope (min) (feet) (ft/ft) 3.8 50 0.0514

Description Unconnected pavement, HSG B Water Surface, HSG B Unconnected roofs, HSG B Woods, Good, HSG A Woods, Good, HSG B Woods, Good, HSG D >75% Grass cover, Good, HSG B Meadow, non-grazed, HSG B Weighted Average, UI Adjusted 94.48% Pervious Area 5.52% Impervious Area 75.35% Unconnected Velocity (ft/sec) 0.22

4.3

208

0.0133

0.81

1.3

168

0.0954

2.16

2.2

121

0.0165

0.90

11.6

547

Total

Capacity (cfs)

Description Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Short Grass Pasture Kv= 7.0 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Short Grass Pasture Kv= 7.0 fps Shallow Concentrated Flow, Shallow Concentrated Flow 3 Short Grass Pasture Kv= 7.0 fps

Summary for Subcatchment 102BS: P-DA-2B Runoff

=

0.39 cfs @ 12.20 hrs, Volume=

0.051 af, Depth> 0.45"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2-YR NRCC Rainfall=3.22" Area (ac) 0.106 1.138 0.106 1.350 1.350

CN 55 58 96 61

Description Woods, Good, HSG B Meadow, non-grazed, HSG B Gravel surface, HSG B Weighted Average 100.00% Pervious Area

2836.00 Post-Development

Type III 24-hr 2-YR NRCC Rainfall=3.22"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Tc Length Slope (min) (feet) (ft/ft) 6.4 50 0.0144 3.4

172

0.1 9.9

Velocity (ft/sec) 0.13

0.0144

0.84

15 0.2000

3.13

237

Capacity (cfs)

Printed 4/26/2017 Page 7

Description Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Short Grass Pasture Kv= 7.0 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Short Grass Pasture Kv= 7.0 fps

Total

Summary for Subcatchment 103AS: P-DA-3A Runoff

=

0.00 cfs @ 21.38 hrs, Volume=

0.002 af, Depth> 0.01"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2-YR NRCC Rainfall=3.22" Area (ac) 0.022 0.013 0.670 0.068 0.198 0.020 0.044 0.021 0.236 1.292 1.257 0.035

CN 98 98 30 55 77 39 61 80 30 42

Tc Length (min) (feet) 6.0

Description Paved parking, HSG A Paved parking, HSG D Woods, Good, HSG A Woods, Good, HSG B Woods, Good, HSG D >75% Grass cover, Good, HSG A >75% Grass cover, Good, HSG B >75% Grass cover, Good, HSG D Meadow, non-grazed, HSG A Weighted Average 97.29% Pervious Area 2.71% Impervious Area Slope (ft/ft)

Velocity (ft/sec)

Capacity (cfs)

Description Direct Entry, Minimum

Summary for Subcatchment 103BS: P-DA-3B Runoff

=

0.54 cfs @ 12.51 hrs, Volume=

0.131 af, Depth> 0.23"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2-YR NRCC Rainfall=3.22"

2836.00 Post-Development

Type III 24-hr 2-YR NRCC Rainfall=3.22"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Area (ac) 0.056 0.252 0.072 0.217 1.924 0.054 0.982 1.191 2.037 0.143 6.928 6.548 0.380 0.072

CN 98 98 98 30 55 39 61 30 58 96 55

Adj

54

Tc Length Slope (min) (feet) (ft/ft) 9.8 50 0.0050

Description Paved parking, HSG A Paved parking, HSG B Unconnected roofs, HSG B Woods, Good, HSG A Woods, Good, HSG B >75% Grass cover, Good, HSG A >75% Grass cover, Good, HSG B Meadow, non-grazed, HSG A Meadow, non-grazed, HSG B Gravel surface, HSG B Weighted Average, UI Adjusted 94.52% Pervious Area 5.48% Impervious Area 18.95% Unconnected Velocity (ft/sec) 0.09

4.3

347

0.0363

1.33

1.8

192

0.0625

1.75

31 0.0955

2.16

0.2 16.1

620

Printed 4/26/2017 Page 8

Capacity (cfs)

Description Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Short Grass Pasture Kv= 7.0 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Short Grass Pasture Kv= 7.0 fps Shallow Concentrated Flow, Shallow Concentrated Flow 3 Short Grass Pasture Kv= 7.0 fps

Total

Summary for Reach 110R: P-DP-1 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = Inflow = Outflow =

10.114 ac, 0.08% Impervious, Inflow Depth = 0.00" for 2-YR NRCC event 0.00 cfs @ 0.00 hrs, Volume= 0.000 af 0.00 cfs @ 0.00 hrs, Volume= 0.000 af, Atten= 0%, Lag= 0.0 min

Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs

Summary for Reach 120R: P-DP-2 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = Inflow = Outflow =

5.248 ac, 4.10% Impervious, Inflow Depth > 0.13" for 2-YR NRCC event 0.19 cfs @ 12.49 hrs, Volume= 0.057 af 0.19 cfs @ 12.49 hrs, Volume= 0.057 af, Atten= 0%, Lag= 0.0 min

Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs

2836.00 Post-Development

Type III 24-hr 2-YR NRCC Rainfall=3.22"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Printed 4/26/2017 Page 9

Summary for Reach 130R: P-DP-3 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = Inflow = Outflow =

8.220 ac, 5.05% Impervious, Inflow Depth > 0.11" for 2-YR NRCC event 0.14 cfs @ 16.22 hrs, Volume= 0.072 af 0.14 cfs @ 16.22 hrs, Volume= 0.072 af, Atten= 0%, Lag= 0.0 min

Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs

Summary for Pond 101AP: BASIN-1 Inflow Area = Inflow = Outflow = Primary =

8.231 ac, 0.10% Impervious, Inflow Depth = 0.00" for 2-YR NRCC event 0.00 cfs @ 0.00 hrs, Volume= 0.000 af 0.00 cfs @ 0.00 hrs, Volume= 0.000 af, Atten= 0%, Lag= 0.0 min 0.00 cfs @ 0.00 hrs, Volume= 0.000 af

Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 493.00' @ 0.00 hrs Surf.Area= 3,844 sf Storage= 0 cf Plug-Flow detention time= (not calculated: initial storage exceeds outflow) Center-of-Mass det. time= (not calculated: no inflow) Volume #1

Invert 493.00'

Elevation (feet) 493.00 494.00 496.00 Device #1

Avail.Storage 30,824 cf

Surf.Area (sq-ft) 3,844 8,790 15,717

Routing Primary

Invert 495.00'

#2

Primary

494.00'

#3

Primary

493.75'

Storage Description Custom Stage Data (Prismatic)Listed below (Recalc)

Inc.Store (cubic-feet) 0 6,317 24,507

Cum.Store (cubic-feet) 0 6,317 30,824

Outlet Devices 20.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 12.0" Round Culvert L= 30.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 494.00' / 493.00' S= 0.0333 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf 12.0" Round Culvert L= 30.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 493.75' / 493.00' S= 0.0250 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf

Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=493.00' (Free Discharge) 1=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) 2=Culvert ( Controls 0.00 cfs) 3=Culvert ( Controls 0.00 cfs)

2836.00 Post-Development

Type III 24-hr 2-YR NRCC Rainfall=3.22"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Printed 4/26/2017 Page 10

Summary for Pond 102P: BASIN-2 Inflow Area = Inflow = Outflow = Primary =

1.350 ac, 0.00% Impervious, Inflow Depth > 0.45" for 2-YR NRCC event 0.39 cfs @ 12.20 hrs, Volume= 0.051 af 0.00 cfs @ 0.00 hrs, Volume= 0.000 af, Atten= 100%, Lag= 0.0 min 0.00 cfs @ 0.00 hrs, Volume= 0.000 af

Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 526.21' @ 24.00 hrs Surf.Area= 11,073 sf Storage= 2,207 cf Plug-Flow detention time= (not calculated: initial storage exceeds outflow) Center-of-Mass det. time= (not calculated: no outflow) Volume #1

Invert 526.00'

Elevation (feet) 526.00 528.00 Device #1 #2

Avail.Storage 28,174 cf

Surf.Area (sq-ft) 10,288 17,886

Storage Description Basin (Prismatic) Listed below (Recalc)

Inc.Store (cubic-feet) 0 28,174

Routing Primary

Invert 527.00'

Primary

526.25'

Cum.Store (cubic-feet) 0 28,174

Outlet Devices 20.0' long x 10.0' breadth Riprap Overflow Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 6.0" Round Culvert L= 60.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 526.25' / 525.00' S= 0.0208 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.20 sf

Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=526.00' (Free Discharge) 1=Riprap Overflow Weir ( Controls 0.00 cfs) 2=Culvert ( Controls 0.00 cfs)

Summary for Pond 103P: BASIN-3 Inflow Area = Inflow = Outflow = Primary =

6.928 ac, 0.54 cfs @ 0.13 cfs @ 0.13 cfs @

5.48% Impervious, Inflow Depth > 0.23" for 2-YR NRCC event 12.51 hrs, Volume= 0.131 af 16.20 hrs, Volume= 0.070 af, Atten= 75%, Lag= 221.5 min 16.20 hrs, Volume= 0.070 af

Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 501.52' @ 16.20 hrs Surf.Area= 6,278 sf Storage= 2,867 cf Plug-Flow detention time= 315.9 min calculated for 0.070 af (54% of inflow) Center-of-Mass det. time= 163.4 min ( 1,131.9 - 968.6 )

2836.00 Post-Development

Type III 24-hr 2-YR NRCC Rainfall=3.22"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Volume #1

Invert 501.00'

Elevation (feet) 501.00 502.00 504.00 Device #1

Avail.Storage 28,347 cf

Surf.Area (sq-ft) 4,660 7,748 14,395

Routing Primary

Invert 503.00'

#2

Primary

501.42'

#3

Primary

501.42'

Printed 4/26/2017 Page 11

Storage Description Custom Stage Data (Prismatic)Listed below (Recalc)

Inc.Store (cubic-feet) 0 6,204 22,143

Cum.Store (cubic-feet) 0 6,204 28,347

Outlet Devices 20.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 12.0" Round Culvert X 2.00 L= 35.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 501.42' / 500.00' S= 0.0406 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf 15.0" Round Culvert L= 35.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 501.42' / 500.00' S= 0.0406 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 1.23 sf

Primary OutFlow Max=0.13 cfs @ 16.20 hrs HW=501.52' (Free Discharge) 1=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) 2=Culvert (Inlet Controls 0.08 cfs @ 0.97 fps) 3=Culvert (Inlet Controls 0.05 cfs @ 0.97 fps)

2836.00 Post-Development

Type III 24-hr 10-YR NRCC Rainfall=4.81"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Printed 4/26/2017 Page 12

Summary for Subcatchment 101AS: P-DA-1A [73] Warning: Peak may fall outside time span Runoff

=

0.00 cfs @ 24.00 hrs, Volume=

0.000 af, Depth> 0.00"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10-YR NRCC Rainfall=4.81" Area (ac) 1.479 0.001 0.403 1.883 1.883

CN 30 77 30 30

Tc Length (min) (feet) 6.0

Description Woods, Good, HSG A Woods, Good, HSG D Meadow, non-grazed, HSG A Weighted Average 100.00% Pervious Area Slope (ft/ft)

Velocity (ft/sec)

Capacity (cfs)

Description Direct Entry, Minimum

Summary for Subcatchment 101BS: P-DA-1B Runoff

=

0.15 cfs @ 14.94 hrs, Volume=

0.090 af, Depth> 0.13"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10-YR NRCC Rainfall=4.81" Area (ac) 0.452 2.021 5.336 0.363 0.008 0.051 8.231 8.223 0.008 0.008

CN 30 55 30 58 98 96 38

Description Woods, Good, HSG A Woods, Good, HSG B Meadow, non-grazed, HSG A Meadow, non-grazed, HSG B Unconnected pavement, HSG B Gravel surface, HSG B Weighted Average 99.90% Pervious Area 0.10% Impervious Area 100.00% Unconnected

Tc Length Slope (min) (feet) (ft/ft) 13.0 50 0.0690

Velocity (ft/sec) 0.06

12.8

292

0.0231

0.38

5.4

260

0.1045

0.81

31.2

602

Total

Capacity (cfs)

Description Sheet Flow, Sheet Flow Woods: Dense underbrush n= 0.800 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Forest w/Heavy Litter Kv= 2.5 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Forest w/Heavy Litter Kv= 2.5 fps

2836.00 Post-Development

Type III 24-hr 10-YR NRCC Rainfall=4.81"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Printed 4/26/2017 Page 13

Summary for Subcatchment 102AS: P-DA-2A Runoff

=

1.81 cfs @ 12.22 hrs, Volume=

0.233 af, Depth> 0.72"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10-YR NRCC Rainfall=4.81" Area (ac) 0.105 0.053 0.057 1.156 0.773 0.117 1.205 0.432 3.898 3.683 0.215 0.162

CN 98 98 98 30 55 77 61 58 53

Adj

52

Tc Length Slope (min) (feet) (ft/ft) 3.8 50 0.0514

Description Unconnected pavement, HSG B Water Surface, HSG B Unconnected roofs, HSG B Woods, Good, HSG A Woods, Good, HSG B Woods, Good, HSG D >75% Grass cover, Good, HSG B Meadow, non-grazed, HSG B Weighted Average, UI Adjusted 94.48% Pervious Area 5.52% Impervious Area 75.35% Unconnected Velocity (ft/sec) 0.22

4.3

208

0.0133

0.81

1.3

168

0.0954

2.16

2.2

121

0.0165

0.90

11.6

547

Total

Capacity (cfs)

Description Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Short Grass Pasture Kv= 7.0 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Short Grass Pasture Kv= 7.0 fps Shallow Concentrated Flow, Shallow Concentrated Flow 3 Short Grass Pasture Kv= 7.0 fps

Summary for Subcatchment 102BS: P-DA-2B Runoff

=

1.54 cfs @ 12.16 hrs, Volume=

0.141 af, Depth> 1.25"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10-YR NRCC Rainfall=4.81" Area (ac) 0.106 1.138 0.106 1.350 1.350

CN 55 58 96 61

Description Woods, Good, HSG B Meadow, non-grazed, HSG B Gravel surface, HSG B Weighted Average 100.00% Pervious Area

2836.00 Post-Development

Type III 24-hr 10-YR NRCC Rainfall=4.81"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Tc Length Slope (min) (feet) (ft/ft) 6.4 50 0.0144 3.4

172

0.1 9.9

Velocity (ft/sec) 0.13

0.0144

0.84

15 0.2000

3.13

237

Capacity (cfs)

Printed 4/26/2017 Page 14

Description Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Short Grass Pasture Kv= 7.0 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Short Grass Pasture Kv= 7.0 fps

Total

Summary for Subcatchment 103AS: P-DA-3A Runoff

=

0.10 cfs @ 12.41 hrs, Volume=

0.028 af, Depth> 0.26"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10-YR NRCC Rainfall=4.81" Area (ac) 0.022 0.013 0.670 0.068 0.198 0.020 0.044 0.021 0.236 1.292 1.257 0.035

CN 98 98 30 55 77 39 61 80 30 42

Tc Length (min) (feet) 6.0

Description Paved parking, HSG A Paved parking, HSG D Woods, Good, HSG A Woods, Good, HSG B Woods, Good, HSG D >75% Grass cover, Good, HSG A >75% Grass cover, Good, HSG B >75% Grass cover, Good, HSG D Meadow, non-grazed, HSG A Weighted Average 97.29% Pervious Area 2.71% Impervious Area Slope (ft/ft)

Velocity (ft/sec)

Capacity (cfs)

Description Direct Entry, Minimum

Summary for Subcatchment 103BS: P-DA-3B Runoff

=

3.64 cfs @ 12.29 hrs, Volume=

0.477 af, Depth> 0.83"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10-YR NRCC Rainfall=4.81"

2836.00 Post-Development

Type III 24-hr 10-YR NRCC Rainfall=4.81"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Area (ac) 0.056 0.252 0.072 0.217 1.924 0.054 0.982 1.191 2.037 0.143 6.928 6.548 0.380 0.072

CN 98 98 98 30 55 39 61 30 58 96 55

Adj

54

Tc Length Slope (min) (feet) (ft/ft) 9.8 50 0.0050

Description Paved parking, HSG A Paved parking, HSG B Unconnected roofs, HSG B Woods, Good, HSG A Woods, Good, HSG B >75% Grass cover, Good, HSG A >75% Grass cover, Good, HSG B Meadow, non-grazed, HSG A Meadow, non-grazed, HSG B Gravel surface, HSG B Weighted Average, UI Adjusted 94.52% Pervious Area 5.48% Impervious Area 18.95% Unconnected Velocity (ft/sec) 0.09

4.3

347

0.0363

1.33

1.8

192

0.0625

1.75

31 0.0955

2.16

0.2 16.1

620

Printed 4/26/2017 Page 15

Capacity (cfs)

Description Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Short Grass Pasture Kv= 7.0 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Short Grass Pasture Kv= 7.0 fps Shallow Concentrated Flow, Shallow Concentrated Flow 3 Short Grass Pasture Kv= 7.0 fps

Total

Summary for Reach 110R: P-DP-1 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = Inflow = Outflow =

10.114 ac, 0.08% Impervious, Inflow Depth > 0.00" for 10-YR NRCC event 0.00 cfs @ 24.00 hrs, Volume= 0.000 af 0.00 cfs @ 24.00 hrs, Volume= 0.000 af, Atten= 0%, Lag= 0.0 min

Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs

Summary for Reach 120R: P-DP-2 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = Inflow = Outflow =

5.248 ac, 4.10% Impervious, Inflow Depth > 0.63" for 10-YR NRCC event 1.81 cfs @ 12.22 hrs, Volume= 0.277 af 1.81 cfs @ 12.22 hrs, Volume= 0.277 af, Atten= 0%, Lag= 0.0 min

Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs

2836.00 Post-Development

Type III 24-hr 10-YR NRCC Rainfall=4.81"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Printed 4/26/2017 Page 16

Summary for Reach 130R: P-DP-3 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = Inflow = Outflow =

8.220 ac, 5.05% Impervious, Inflow Depth > 0.64" for 10-YR NRCC event 1.85 cfs @ 12.69 hrs, Volume= 0.439 af 1.85 cfs @ 12.69 hrs, Volume= 0.439 af, Atten= 0%, Lag= 0.0 min

Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs

Summary for Pond 101AP: BASIN-1 Inflow Area = Inflow = Outflow = Primary =

8.231 ac, 0.10% Impervious, Inflow Depth > 0.13" for 10-YR NRCC event 0.15 cfs @ 14.94 hrs, Volume= 0.090 af 0.00 cfs @ 0.00 hrs, Volume= 0.000 af, Atten= 100%, Lag= 0.0 min 0.00 cfs @ 0.00 hrs, Volume= 0.000 af

Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 493.70' @ 24.00 hrs Surf.Area= 7,305 sf Storage= 3,901 cf Plug-Flow detention time= (not calculated: initial storage exceeds outflow) Center-of-Mass det. time= (not calculated: no outflow) Volume #1

Invert 493.00'

Elevation (feet) 493.00 494.00 496.00 Device #1

Avail.Storage 30,824 cf

Surf.Area (sq-ft) 3,844 8,790 15,717

Routing Primary

Invert 495.00'

#2

Primary

494.00'

#3

Primary

493.75'

Storage Description Custom Stage Data (Prismatic)Listed below (Recalc)

Inc.Store (cubic-feet) 0 6,317 24,507

Cum.Store (cubic-feet) 0 6,317 30,824

Outlet Devices 20.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 12.0" Round Culvert L= 30.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 494.00' / 493.00' S= 0.0333 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf 12.0" Round Culvert L= 30.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 493.75' / 493.00' S= 0.0250 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf

Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=493.00' (Free Discharge) 1=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) 2=Culvert ( Controls 0.00 cfs) 3=Culvert ( Controls 0.00 cfs)

2836.00 Post-Development

Type III 24-hr 10-YR NRCC Rainfall=4.81"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Printed 4/26/2017 Page 17

Summary for Pond 102P: BASIN-2 Inflow Area = Inflow = Outflow = Primary =

1.350 ac, 1.54 cfs @ 0.06 cfs @ 0.06 cfs @

0.00% Impervious, Inflow Depth > 1.25" for 10-YR NRCC event 12.16 hrs, Volume= 0.141 af 18.05 hrs, Volume= 0.044 af, Atten= 96%, Lag= 353.3 min 18.05 hrs, Volume= 0.044 af

Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 526.40' @ 18.05 hrs Surf.Area= 11,819 sf Storage= 4,455 cf Plug-Flow detention time= 419.6 min calculated for 0.043 af (31% of inflow) Center-of-Mass det. time= 271.6 min ( 1,148.9 - 877.4 ) Volume #1

Invert 526.00'

Elevation (feet) 526.00 528.00 Device #1 #2

Avail.Storage 28,174 cf

Surf.Area (sq-ft) 10,288 17,886

Storage Description Basin (Prismatic) Listed below (Recalc)

Inc.Store (cubic-feet) 0 28,174

Routing Primary

Invert 527.00'

Primary

526.25'

Cum.Store (cubic-feet) 0 28,174

Outlet Devices 20.0' long x 10.0' breadth Riprap Overflow Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 6.0" Round Culvert L= 60.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 526.25' / 525.00' S= 0.0208 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.20 sf

Primary OutFlow Max=0.06 cfs @ 18.05 hrs HW=526.40' (Free Discharge) 1=Riprap Overflow Weir ( Controls 0.00 cfs) 2=Culvert (Inlet Controls 0.06 cfs @ 1.18 fps)

Summary for Pond 103P: BASIN-3 Inflow Area = Inflow = Outflow = Primary =

6.928 ac, 3.64 cfs @ 1.78 cfs @ 1.78 cfs @

5.48% Impervious, Inflow Depth > 0.83" for 10-YR NRCC event 12.29 hrs, Volume= 0.477 af 12.69 hrs, Volume= 0.410 af, Atten= 51%, Lag= 24.1 min 12.69 hrs, Volume= 0.410 af

Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 501.82' @ 12.69 hrs Surf.Area= 7,201 sf Storage= 4,880 cf Plug-Flow detention time= 108.1 min calculated for 0.410 af (86% of inflow) Center-of-Mass det. time= 45.8 min ( 952.9 - 907.2 )

2836.00 Post-Development

Type III 24-hr 10-YR NRCC Rainfall=4.81"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Volume #1

Invert 501.00'

Elevation (feet) 501.00 502.00 504.00 Device #1

Avail.Storage 28,347 cf

Surf.Area (sq-ft) 4,660 7,748 14,395

Routing Primary

Invert 503.00'

#2

Primary

501.42'

#3

Primary

501.42'

Printed 4/26/2017 Page 18

Storage Description Custom Stage Data (Prismatic)Listed below (Recalc)

Inc.Store (cubic-feet) 0 6,204 22,143

Cum.Store (cubic-feet) 0 6,204 28,347

Outlet Devices 20.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 12.0" Round Culvert X 2.00 L= 35.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 501.42' / 500.00' S= 0.0406 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf 15.0" Round Culvert L= 35.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 501.42' / 500.00' S= 0.0406 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 1.23 sf

Primary OutFlow Max=1.78 cfs @ 12.69 hrs HW=501.82' (Free Discharge) 1=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) 2=Culvert (Inlet Controls 1.13 cfs @ 1.91 fps) 3=Culvert (Inlet Controls 0.65 cfs @ 1.91 fps)

2836.00 Post-Development

Type III 24-hr 25-YR NRCC Rainfall=6.05"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Printed 4/26/2017 Page 19

Summary for Subcatchment 101AS: P-DA-1A Runoff

=

0.02 cfs @ 15.43 hrs, Volume=

0.012 af, Depth> 0.08"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 25-YR NRCC Rainfall=6.05" Area (ac) 1.479 0.001 0.403 1.883 1.883

CN 30 77 30 30

Tc Length (min) (feet) 6.0

Description Woods, Good, HSG A Woods, Good, HSG D Meadow, non-grazed, HSG A Weighted Average 100.00% Pervious Area Slope (ft/ft)

Velocity (ft/sec)

Capacity (cfs)

Description Direct Entry, Minimum

Summary for Subcatchment 101BS: P-DA-1B Runoff

=

0.86 cfs @ 12.75 hrs, Volume=

0.274 af, Depth> 0.40"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 25-YR NRCC Rainfall=6.05" Area (ac) 0.452 2.021 5.336 0.363 0.008 0.051 8.231 8.223 0.008 0.008

CN 30 55 30 58 98 96 38

Description Woods, Good, HSG A Woods, Good, HSG B Meadow, non-grazed, HSG A Meadow, non-grazed, HSG B Unconnected pavement, HSG B Gravel surface, HSG B Weighted Average 99.90% Pervious Area 0.10% Impervious Area 100.00% Unconnected

Tc Length Slope (min) (feet) (ft/ft) 13.0 50 0.0690

Velocity (ft/sec) 0.06

12.8

292

0.0231

0.38

5.4

260

0.1045

0.81

31.2

602

Total

Capacity (cfs)

Description Sheet Flow, Sheet Flow Woods: Dense underbrush n= 0.800 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Forest w/Heavy Litter Kv= 2.5 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Forest w/Heavy Litter Kv= 2.5 fps

2836.00 Post-Development

Type III 24-hr 25-YR NRCC Rainfall=6.05"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Printed 4/26/2017 Page 20

Summary for Subcatchment 102AS: P-DA-2A Runoff

=

4.10 cfs @ 12.19 hrs, Volume=

0.426 af, Depth> 1.31"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 25-YR NRCC Rainfall=6.05" Area (ac) 0.105 0.053 0.057 1.156 0.773 0.117 1.205 0.432 3.898 3.683 0.215 0.162

CN 98 98 98 30 55 77 61 58 53

Adj

52

Tc Length Slope (min) (feet) (ft/ft) 3.8 50 0.0514

Description Unconnected pavement, HSG B Water Surface, HSG B Unconnected roofs, HSG B Woods, Good, HSG A Woods, Good, HSG B Woods, Good, HSG D >75% Grass cover, Good, HSG B Meadow, non-grazed, HSG B Weighted Average, UI Adjusted 94.48% Pervious Area 5.52% Impervious Area 75.35% Unconnected Velocity (ft/sec) 0.22

4.3

208

0.0133

0.81

1.3

168

0.0954

2.16

2.2

121

0.0165

0.90

11.6

547

Total

Capacity (cfs)

Description Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Short Grass Pasture Kv= 7.0 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Short Grass Pasture Kv= 7.0 fps Shallow Concentrated Flow, Shallow Concentrated Flow 3 Short Grass Pasture Kv= 7.0 fps

Summary for Subcatchment 102BS: P-DA-2B Runoff

=

2.66 cfs @ 12.15 hrs, Volume=

0.229 af, Depth> 2.03"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 25-YR NRCC Rainfall=6.05" Area (ac) 0.106 1.138 0.106 1.350 1.350

CN 55 58 96 61

Description Woods, Good, HSG B Meadow, non-grazed, HSG B Gravel surface, HSG B Weighted Average 100.00% Pervious Area

2836.00 Post-Development

Type III 24-hr 25-YR NRCC Rainfall=6.05"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Tc Length Slope (min) (feet) (ft/ft) 6.4 50 0.0144 3.4

172

0.1 9.9

Velocity (ft/sec) 0.13

0.0144

0.84

15 0.2000

3.13

237

Capacity (cfs)

Printed 4/26/2017 Page 21

Description Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Short Grass Pasture Kv= 7.0 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Short Grass Pasture Kv= 7.0 fps

Total

Summary for Subcatchment 103AS: P-DA-3A Runoff

=

0.43 cfs @ 12.17 hrs, Volume=

0.068 af, Depth> 0.63"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 25-YR NRCC Rainfall=6.05" Area (ac) 0.022 0.013 0.670 0.068 0.198 0.020 0.044 0.021 0.236 1.292 1.257 0.035

CN 98 98 30 55 77 39 61 80 30 42

Tc Length (min) (feet) 6.0

Description Paved parking, HSG A Paved parking, HSG D Woods, Good, HSG A Woods, Good, HSG B Woods, Good, HSG D >75% Grass cover, Good, HSG A >75% Grass cover, Good, HSG B >75% Grass cover, Good, HSG D Meadow, non-grazed, HSG A Weighted Average 97.29% Pervious Area 2.71% Impervious Area Slope (ft/ft)

Velocity (ft/sec)

Capacity (cfs)

Description Direct Entry, Minimum

Summary for Subcatchment 103BS: P-DA-3B Runoff

=

7.58 cfs @ 12.26 hrs, Volume=

0.844 af, Depth> 1.46"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 25-YR NRCC Rainfall=6.05"

2836.00 Post-Development

Type III 24-hr 25-YR NRCC Rainfall=6.05"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Area (ac) 0.056 0.252 0.072 0.217 1.924 0.054 0.982 1.191 2.037 0.143 6.928 6.548 0.380 0.072

CN 98 98 98 30 55 39 61 30 58 96 55

Adj

54

Tc Length Slope (min) (feet) (ft/ft) 9.8 50 0.0050

Description Paved parking, HSG A Paved parking, HSG B Unconnected roofs, HSG B Woods, Good, HSG A Woods, Good, HSG B >75% Grass cover, Good, HSG A >75% Grass cover, Good, HSG B Meadow, non-grazed, HSG A Meadow, non-grazed, HSG B Gravel surface, HSG B Weighted Average, UI Adjusted 94.52% Pervious Area 5.48% Impervious Area 18.95% Unconnected Velocity (ft/sec) 0.09

4.3

347

0.0363

1.33

1.8

192

0.0625

1.75

31 0.0955

2.16

0.2 16.1

620

Printed 4/26/2017 Page 22

Capacity (cfs)

Description Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Short Grass Pasture Kv= 7.0 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Short Grass Pasture Kv= 7.0 fps Shallow Concentrated Flow, Shallow Concentrated Flow 3 Short Grass Pasture Kv= 7.0 fps

Total

Summary for Reach 110R: P-DP-1 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = Inflow = Outflow =

10.114 ac, 0.08% Impervious, Inflow Depth > 0.18" for 25-YR NRCC event 0.26 cfs @ 17.39 hrs, Volume= 0.153 af 0.26 cfs @ 17.39 hrs, Volume= 0.153 af, Atten= 0%, Lag= 0.0 min

Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs

Summary for Reach 120R: P-DP-2 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = Inflow = Outflow =

5.248 ac, 4.10% Impervious, Inflow Depth > 1.25" for 25-YR NRCC event 4.10 cfs @ 12.19 hrs, Volume= 0.547 af 4.10 cfs @ 12.19 hrs, Volume= 0.547 af, Atten= 0%, Lag= 0.0 min

Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs

2836.00 Post-Development

Type III 24-hr 25-YR NRCC Rainfall=6.05"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Printed 4/26/2017 Page 23

Summary for Reach 130R: P-DP-3 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = Inflow = Outflow =

8.220 ac, 5.05% Impervious, Inflow Depth > 1.23" for 25-YR NRCC event 5.19 cfs @ 12.51 hrs, Volume= 0.842 af 5.19 cfs @ 12.51 hrs, Volume= 0.842 af, Atten= 0%, Lag= 0.0 min

Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs

Summary for Pond 101AP: BASIN-1 Inflow Area = Inflow = Outflow = Primary =

8.231 ac, 0.86 cfs @ 0.24 cfs @ 0.24 cfs @

0.10% Impervious, Inflow Depth > 0.40" for 25-YR NRCC event 12.75 hrs, Volume= 0.274 af 17.44 hrs, Volume= 0.140 af, Atten= 72%, Lag= 281.9 min 17.44 hrs, Volume= 0.140 af

Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 494.01' @ 17.44 hrs Surf.Area= 8,808 sf Storage= 6,364 cf Plug-Flow detention time= 332.1 min calculated for 0.140 af (51% of inflow) Center-of-Mass det. time= 176.5 min ( 1,159.5 - 983.0 ) Volume #1

Invert 493.00'

Elevation (feet) 493.00 494.00 496.00 Device #1

Avail.Storage 30,824 cf

Surf.Area (sq-ft) 3,844 8,790 15,717

Routing Primary

Invert 495.00'

#2

Primary

494.00'

#3

Primary

493.75'

Storage Description Custom Stage Data (Prismatic)Listed below (Recalc)

Inc.Store (cubic-feet) 0 6,317 24,507

Cum.Store (cubic-feet) 0 6,317 30,824

Outlet Devices 20.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 12.0" Round Culvert L= 30.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 494.00' / 493.00' S= 0.0333 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf 12.0" Round Culvert L= 30.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 493.75' / 493.00' S= 0.0250 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf

Primary OutFlow Max=0.24 cfs @ 17.44 hrs HW=494.01' (Free Discharge) 1=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) 2=Culvert (Inlet Controls 0.00 cfs @ 0.22 fps) 3=Culvert (Inlet Controls 0.24 cfs @ 1.52 fps)

2836.00 Post-Development

Type III 24-hr 25-YR NRCC Rainfall=6.05"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Printed 4/26/2017 Page 24

Summary for Pond 102P: BASIN-2 Inflow Area = Inflow = Outflow = Primary =

1.350 ac, 2.66 cfs @ 0.17 cfs @ 0.17 cfs @

0.00% Impervious, Inflow Depth > 2.03" for 25-YR NRCC event 12.15 hrs, Volume= 0.229 af 15.45 hrs, Volume= 0.121 af, Atten= 93%, Lag= 198.0 min 15.45 hrs, Volume= 0.121 af

Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 526.52' @ 15.45 hrs Surf.Area= 12,279 sf Storage= 5,914 cf Plug-Flow detention time= 326.6 min calculated for 0.120 af (53% of inflow) Center-of-Mass det. time= 201.0 min ( 1,063.0 - 862.0 ) Volume #1

Invert 526.00'

Elevation (feet) 526.00 528.00 Device #1 #2

Avail.Storage 28,174 cf

Surf.Area (sq-ft) 10,288 17,886

Storage Description Basin (Prismatic) Listed below (Recalc)

Inc.Store (cubic-feet) 0 28,174

Routing Primary

Invert 527.00'

Primary

526.25'

Cum.Store (cubic-feet) 0 28,174

Outlet Devices 20.0' long x 10.0' breadth Riprap Overflow Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 6.0" Round Culvert L= 60.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 526.25' / 525.00' S= 0.0208 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.20 sf

Primary OutFlow Max=0.17 cfs @ 15.45 hrs HW=526.52' (Free Discharge) 1=Riprap Overflow Weir ( Controls 0.00 cfs) 2=Culvert (Inlet Controls 0.17 cfs @ 1.57 fps)

Summary for Pond 103P: BASIN-3 Inflow Area = Inflow = Outflow = Primary =

6.928 ac, 7.58 cfs @ 4.93 cfs @ 4.93 cfs @

5.48% Impervious, Inflow Depth > 1.46" for 25-YR NRCC event 12.26 hrs, Volume= 0.844 af 12.53 hrs, Volume= 0.774 af, Atten= 35%, Lag= 16.1 min 12.53 hrs, Volume= 0.774 af

Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 502.14' @ 12.53 hrs Surf.Area= 8,206 sf Storage= 7,303 cf Plug-Flow detention time= 69.8 min calculated for 0.772 af (91% of inflow) Center-of-Mass det. time= 29.5 min ( 915.9 - 886.4 )

2836.00 Post-Development

Type III 24-hr 25-YR NRCC Rainfall=6.05"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Volume #1

Invert 501.00'

Elevation (feet) 501.00 502.00 504.00 Device #1

Avail.Storage 28,347 cf

Surf.Area (sq-ft) 4,660 7,748 14,395

Routing Primary

Invert 503.00'

#2

Primary

501.42'

#3

Primary

501.42'

Printed 4/26/2017 Page 25

Storage Description Custom Stage Data (Prismatic)Listed below (Recalc)

Inc.Store (cubic-feet) 0 6,204 22,143

Cum.Store (cubic-feet) 0 6,204 28,347

Outlet Devices 20.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 12.0" Round Culvert X 2.00 L= 35.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 501.42' / 500.00' S= 0.0406 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf 15.0" Round Culvert L= 35.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 501.42' / 500.00' S= 0.0406 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 1.23 sf

Primary OutFlow Max=4.91 cfs @ 12.53 hrs HW=502.14' (Free Discharge) 1=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) 2=Culvert (Inlet Controls 3.06 cfs @ 2.54 fps) 3=Culvert (Inlet Controls 1.85 cfs @ 2.54 fps)

2836.00 Post-Development

Type III 24-hr 100-YR NRCC Rainfall=8.59"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Printed 4/26/2017 Page 26

Summary for Subcatchment 101AS: P-DA-1A Runoff

=

0.38 cfs @ 12.37 hrs, Volume=

0.088 af, Depth> 0.56"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100-YR NRCC Rainfall=8.59" Area (ac) 1.479 0.001 0.403 1.883 1.883

CN 30 77 30 30

Tc Length (min) (feet) 6.0

Description Woods, Good, HSG A Woods, Good, HSG D Meadow, non-grazed, HSG A Weighted Average 100.00% Pervious Area Slope (ft/ft)

Velocity (ft/sec)

Capacity (cfs)

Description Direct Entry, Minimum

Summary for Subcatchment 101BS: P-DA-1B Runoff

=

5.05 cfs @ 12.57 hrs, Volume=

0.889 af, Depth> 1.30"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100-YR NRCC Rainfall=8.59" Area (ac) 0.452 2.021 5.336 0.363 0.008 0.051 8.231 8.223 0.008 0.008

CN 30 55 30 58 98 96 38

Description Woods, Good, HSG A Woods, Good, HSG B Meadow, non-grazed, HSG A Meadow, non-grazed, HSG B Unconnected pavement, HSG B Gravel surface, HSG B Weighted Average 99.90% Pervious Area 0.10% Impervious Area 100.00% Unconnected

Tc Length Slope (min) (feet) (ft/ft) 13.0 50 0.0690

Velocity (ft/sec) 0.06

12.8

292

0.0231

0.38

5.4

260

0.1045

0.81

31.2

602

Total

Capacity (cfs)

Description Sheet Flow, Sheet Flow Woods: Dense underbrush n= 0.800 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Forest w/Heavy Litter Kv= 2.5 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Forest w/Heavy Litter Kv= 2.5 fps

2836.00 Post-Development

Type III 24-hr 100-YR NRCC Rainfall=8.59"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Printed 4/26/2017 Page 27

Summary for Subcatchment 102AS: P-DA-2A Runoff

=

10.17 cfs @ 12.17 hrs, Volume=

0.922 af, Depth> 2.84"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100-YR NRCC Rainfall=8.59" Area (ac) 0.105 0.053 0.057 1.156 0.773 0.117 1.205 0.432 3.898 3.683 0.215 0.162

CN 98 98 98 30 55 77 61 58 53

Adj

52

Tc Length Slope (min) (feet) (ft/ft) 3.8 50 0.0514

Description Unconnected pavement, HSG B Water Surface, HSG B Unconnected roofs, HSG B Woods, Good, HSG A Woods, Good, HSG B Woods, Good, HSG D >75% Grass cover, Good, HSG B Meadow, non-grazed, HSG B Weighted Average, UI Adjusted 94.48% Pervious Area 5.52% Impervious Area 75.35% Unconnected Velocity (ft/sec) 0.22

4.3

208

0.0133

0.81

1.3

168

0.0954

2.16

2.2

121

0.0165

0.90

11.6

547

Total

Capacity (cfs)

Description Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Short Grass Pasture Kv= 7.0 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Short Grass Pasture Kv= 7.0 fps Shallow Concentrated Flow, Shallow Concentrated Flow 3 Short Grass Pasture Kv= 7.0 fps

Summary for Subcatchment 102BS: P-DA-2B Runoff

=

5.30 cfs @ 12.15 hrs, Volume=

0.438 af, Depth> 3.89"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100-YR NRCC Rainfall=8.59" Area (ac) 0.106 1.138 0.106 1.350 1.350

CN 55 58 96 61

Description Woods, Good, HSG B Meadow, non-grazed, HSG B Gravel surface, HSG B Weighted Average 100.00% Pervious Area

2836.00 Post-Development

Type III 24-hr 100-YR NRCC Rainfall=8.59"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Tc Length Slope (min) (feet) (ft/ft) 6.4 50 0.0144 3.4

172

0.1 9.9

Velocity (ft/sec) 0.13

0.0144

0.84

15 0.2000

3.13

237

Capacity (cfs)

Printed 4/26/2017 Page 28

Description Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Short Grass Pasture Kv= 7.0 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Short Grass Pasture Kv= 7.0 fps

Total

Summary for Subcatchment 103AS: P-DA-3A Runoff

=

2.10 cfs @ 12.11 hrs, Volume=

0.186 af, Depth> 1.73"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100-YR NRCC Rainfall=8.59" Area (ac) 0.022 0.013 0.670 0.068 0.198 0.020 0.044 0.021 0.236 1.292 1.257 0.035

CN 98 98 30 55 77 39 61 80 30 42

Tc Length (min) (feet) 6.0

Description Paved parking, HSG A Paved parking, HSG D Woods, Good, HSG A Woods, Good, HSG B Woods, Good, HSG D >75% Grass cover, Good, HSG A >75% Grass cover, Good, HSG B >75% Grass cover, Good, HSG D Meadow, non-grazed, HSG A Weighted Average 97.29% Pervious Area 2.71% Impervious Area Slope (ft/ft)

Velocity (ft/sec)

Capacity (cfs)

Description Direct Entry, Minimum

Summary for Subcatchment 103BS: P-DA-3B Runoff

=

17.53 cfs @ 12.24 hrs, Volume=

1.771 af, Depth> 3.07"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100-YR NRCC Rainfall=8.59"

2836.00 Post-Development

Type III 24-hr 100-YR NRCC Rainfall=8.59"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Area (ac) 0.056 0.252 0.072 0.217 1.924 0.054 0.982 1.191 2.037 0.143 6.928 6.548 0.380 0.072

CN 98 98 98 30 55 39 61 30 58 96 55

Adj

54

Tc Length Slope (min) (feet) (ft/ft) 9.8 50 0.0050

Description Paved parking, HSG A Paved parking, HSG B Unconnected roofs, HSG B Woods, Good, HSG A Woods, Good, HSG B >75% Grass cover, Good, HSG A >75% Grass cover, Good, HSG B Meadow, non-grazed, HSG A Meadow, non-grazed, HSG B Gravel surface, HSG B Weighted Average, UI Adjusted 94.52% Pervious Area 5.48% Impervious Area 18.95% Unconnected Velocity (ft/sec) 0.09

4.3

347

0.0363

1.33

1.8

192

0.0625

1.75

31 0.0955

2.16

0.2 16.1

620

Printed 4/26/2017 Page 29

Capacity (cfs)

Description Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Short Grass Pasture Kv= 7.0 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Short Grass Pasture Kv= 7.0 fps Shallow Concentrated Flow, Shallow Concentrated Flow 3 Short Grass Pasture Kv= 7.0 fps

Total

Summary for Reach 110R: P-DP-1 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = Inflow = Outflow =

10.114 ac, 0.08% Impervious, Inflow Depth > 0.98" for 100-YR NRCC event 2.24 cfs @ 13.27 hrs, Volume= 0.825 af 2.24 cfs @ 13.27 hrs, Volume= 0.825 af, Atten= 0%, Lag= 0.0 min

Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs

Summary for Reach 120R: P-DP-2 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = Inflow = Outflow =

5.248 ac, 4.10% Impervious, Inflow Depth > 2.82" for 100-YR NRCC event 10.19 cfs @ 12.18 hrs, Volume= 1.235 af 10.19 cfs @ 12.18 hrs, Volume= 1.235 af, Atten= 0%, Lag= 0.0 min

Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs

2836.00 Post-Development

Type III 24-hr 100-YR NRCC Rainfall=8.59"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Printed 4/26/2017 Page 30

Summary for Reach 130R: P-DP-3 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = Inflow = Outflow =

8.220 ac, 5.05% Impervious, Inflow Depth > 2.74" for 100-YR NRCC event 12.24 cfs @ 12.43 hrs, Volume= 1.880 af 12.24 cfs @ 12.43 hrs, Volume= 1.880 af, Atten= 0%, Lag= 0.0 min

Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs

Summary for Pond 101AP: BASIN-1 Inflow Area = Inflow = Outflow = Primary =

8.231 ac, 5.05 cfs @ 2.07 cfs @ 2.07 cfs @

0.10% Impervious, Inflow Depth > 1.30" for 100-YR NRCC event 12.57 hrs, Volume= 0.889 af 13.27 hrs, Volume= 0.736 af, Atten= 59%, Lag= 42.5 min 13.27 hrs, Volume= 0.736 af

Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 494.43' @ 13.27 hrs Surf.Area= 10,296 sf Storage= 10,466 cf Plug-Flow detention time= 134.8 min calculated for 0.735 af (83% of inflow) Center-of-Mass det. time= 63.0 min ( 988.8 - 925.8 ) Volume #1

Invert 493.00'

Elevation (feet) 493.00 494.00 496.00 Device #1

Avail.Storage 30,824 cf

Surf.Area (sq-ft) 3,844 8,790 15,717

Routing Primary

Invert 495.00'

#2

Primary

494.00'

#3

Primary

493.75'

Storage Description Custom Stage Data (Prismatic)Listed below (Recalc)

Inc.Store (cubic-feet) 0 6,317 24,507

Cum.Store (cubic-feet) 0 6,317 30,824

Outlet Devices 20.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 12.0" Round Culvert L= 30.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 494.00' / 493.00' S= 0.0333 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf 12.0" Round Culvert L= 30.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 493.75' / 493.00' S= 0.0250 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf

Primary OutFlow Max=2.07 cfs @ 13.27 hrs HW=494.43' (Free Discharge) 1=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) 2=Culvert (Inlet Controls 0.65 cfs @ 1.98 fps) 3=Culvert (Inlet Controls 1.42 cfs @ 2.49 fps)

2836.00 Post-Development

Type III 24-hr 100-YR NRCC Rainfall=8.59"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Printed 4/26/2017 Page 31

Summary for Pond 102P: BASIN-2 Inflow Area = Inflow = Outflow = Primary =

1.350 ac, 5.30 cfs @ 0.49 cfs @ 0.49 cfs @

0.00% Impervious, Inflow Depth > 3.89" for 100-YR NRCC event 12.15 hrs, Volume= 0.438 af 13.76 hrs, Volume= 0.313 af, Atten= 91%, Lag= 96.7 min 13.76 hrs, Volume= 0.313 af

Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 526.84' @ 13.76 hrs Surf.Area= 13,478 sf Storage= 9,976 cf Plug-Flow detention time= 264.8 min calculated for 0.313 af (71% of inflow) Center-of-Mass det. time= 168.8 min ( 1,011.6 - 842.8 ) Volume #1

Invert 526.00'

Elevation (feet) 526.00 528.00 Device #1 #2

Avail.Storage 28,174 cf

Surf.Area (sq-ft) 10,288 17,886

Storage Description Basin (Prismatic) Listed below (Recalc)

Inc.Store (cubic-feet) 0 28,174

Routing Primary

Invert 527.00'

Primary

526.25'

Cum.Store (cubic-feet) 0 28,174

Outlet Devices 20.0' long x 10.0' breadth Riprap Overflow Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 6.0" Round Culvert L= 60.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 526.25' / 525.00' S= 0.0208 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.20 sf

Primary OutFlow Max=0.49 cfs @ 13.76 hrs HW=526.84' (Free Discharge) 1=Riprap Overflow Weir ( Controls 0.00 cfs) 2=Culvert (Inlet Controls 0.49 cfs @ 2.48 fps)

Summary for Pond 103P: BASIN-3 Inflow Area = Inflow = Outflow = Primary =

6.928 ac, 17.53 cfs @ 11.36 cfs @ 11.36 cfs @

5.48% Impervious, Inflow Depth > 3.07" for 100-YR NRCC event 12.24 hrs, Volume= 1.771 af 12.48 hrs, Volume= 1.694 af, Atten= 35%, Lag= 14.4 min 12.48 hrs, Volume= 1.694 af

Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 502.89' @ 12.48 hrs Surf.Area= 10,704 sf Storage= 14,409 cf Plug-Flow detention time= 43.8 min calculated for 1.694 af (96% of inflow) Center-of-Mass det. time= 20.8 min ( 883.8 - 863.0 )

2836.00 Post-Development

Type III 24-hr 100-YR NRCC Rainfall=8.59"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Volume #1

Invert 501.00'

Elevation (feet) 501.00 502.00 504.00 Device #1

Avail.Storage 28,347 cf

Surf.Area (sq-ft) 4,660 7,748 14,395

Routing Primary

Invert 503.00'

#2

Primary

501.42'

#3

Primary

501.42'

Printed 4/26/2017 Page 32

Storage Description Custom Stage Data (Prismatic)Listed below (Recalc)

Inc.Store (cubic-feet) 0 6,204 22,143

Cum.Store (cubic-feet) 0 6,204 28,347

Outlet Devices 20.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 12.0" Round Culvert X 2.00 L= 35.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 501.42' / 500.00' S= 0.0406 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf 15.0" Round Culvert L= 35.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 501.42' / 500.00' S= 0.0406 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 1.23 sf

Primary OutFlow Max=11.35 cfs @ 12.48 hrs HW=502.89' (Free Discharge) 1=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) 2=Culvert (Inlet Controls 6.56 cfs @ 4.18 fps) 3=Culvert (Inlet Controls 4.78 cfs @ 3.90 fps)

Appendix D Drawdown & Riprap-Sizing Calculation

BEALS+THOMAS Standard 3: Drawdown

Rv (K) (Bottom Area)

Drawdown Time =

where:

Rv = Storage Volume Below Outlet [Ac-ft] K= Infiltration Rate [in/hr] Bottom Area= Bottom Area of Recharge System [Ac]

Basin 1 Rv =

0.107 Ac-ft

K=

0.270 in/hr

Bottom Area =

0.088 Acres

Drawdown Time =

53.856 Hours

(Mapped as HSG "A" & "B"; Rawls Rate for HSG "C" Soils) < 72 Hours, Design is in compliance with the standard.

Basin 2 Rv =

0.075 Ac-ft

K=

0.270 in/hr

Bottom Area =

0.236 Acres

Drawdown Time =

14.070 Hours

(Mapped as HSG "A" & "B"; Rawls Rate for HSG "C" Soils) < 72 Hours, Design is in compliance with the standard.

Basin 3 Rv =

0.062 Ac-ft

K=

0.270 in/hr

Bottom Area =

0.107 Acres

Drawdown Time =

25.904 Hours

(Mapped as HSG "A" & "B"; Rawls Rate for HSG "C" Soils) < 72 Hours, Design is in compliance with the standard.

Note: 1. The infiltration BMPs have been designed to fully drain within 72 hours, therefore the proposed stormwater management design is in compliance with Standard 3 . 2. Infiltration Rate based on Volume 3, Chapter 1, Table 2.3.3 Rawls Rates from the 2008 MA DEP Stormwater Management Handbook. JOB NO. JOB:

283600SWM0001.xlsx

2836.00 CEC Solar #1206, LLC

COMPUTED BY: DATE:

TJM 08/09/17

CHECKED BY: DATE:

BEALS+THOMAS Riprap Apron Sizing

Median Stone Sizing: Where: D0 = Maximum Inside Pipe Diameter (ft) D50 = Median Riprap Diameter (ft) Q = Peak Discharge Rate from Hydraulic Design (cfs) TW = Tailwater Depth (ft); (Use 0.4D0 if TW is unknown, max 1.0Do) 2

g = Gravitational Acceleration Constant = 32.2 ft/s

Apron Sizing: D50 [In]

Apron Length (L) [ft}

Apron Depth [In]

Apron Width At Beginning

Apron Width At End

5 6 10 14 20 22

4D0 4D0 5D0 6D0 7D0 8D0

3.5D50 3.3D50 2.4D50 2.2D50 2.0D50 2.0D50

3D0 3D0 3D0 3D0 3D0 3D0

3D0 + ⅔L 3D0 + ⅔L 3D0 + ⅔L 3D0 + ⅔L 3D0 + ⅔L 3D0 + ⅔L

FLARED END SECTIONS

PIPE DIAMETER (D0) (FEET)

25-YEAR STORM FLOW (Q) (CFS)

12"@Basin #1 (2) 6"@Basin #2 (1) 12"@Basin #3 (2) 15" @Basin #3 (1)

1.00 0.50 1.00 1.25

0.24 0.17 3.06 1.85

MEDIAN STONE TAILWATER DIAMETER (TW) [ft] (D50) (INCHES) 0.4 0.2 0.4 0.5

5 5 5 5

APRON LENGTH (L) (FEET)

APRON DEPTH [In]

APRON WIDTH AT BEGINING (W1) [ft]

APRON WIDTH AT END (W2) [ft]

4.00 2.00 4.00 5.00

17.5 17.5 17.5 17.5

3.0 1.5 3.0 3.8

5.7 2.8 5.7 7.1

Notes [1] Calculations performed in accordance with Hydraulic Engineering Circular No. 14, Third Edition; Hydraulic Design of Energy Dissipaters for Culverts and Channels, dated July 2006. [2] Pipe shall extend 1 foot into riprap. [3] For maximum pipe size of 60". JOB NO. JOB:

2836 CEC Solar #1206

283600SWM0001.xlsx

COMPUTED BY: DATE:

TJM 08/14/17

CHECKED BY: DATE:

Appendix E Site Owner’s Manual

SITE OWNER’S MANUAL CEC Solar #1206, LLC 147 Lumber Street Hopkinton, Massachusetts

Prepared for: CEC Solar #1144, LLC c/o Clean Energy Collective 146 West Boylston Drive, 3rd Floor Worcester, MA 01606

Presented by:

BEALS+THOMAS BEALS AND THOMAS, INC. Reservoir Corporate Center 144 Turnpike Road Southborough, MA 01772-2104

August 10, 2017

283600P002

CEC Solar #1206, LLC Site Owner’s Manual Hopkinton, Massachusetts 283600RP002

TABLE OF CONTENTS 1.0

INTRODUCTION .......................................................................................................................................... 1-1

2.0

SITE OWNER’S AGREEMENT ................................................................................................................. 2-1

2.1 2.2 2.3 2.4 3.0

LONG-TERM POLLUTION PREVENTION PLAN ................................................................................ 3-1

3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 4.0

OPERATION AND MAINTENANCE COMPLIANCE STATEMENT........................................................................ 2-1 STORMWATER MAINTENANCE EASEMENTS ................................................................................................. 2-1 RECORD KEEPING ........................................................................................................................................ 2-1 TRAINING ..................................................................................................................................................... 2-2

STORAGE OF MATERIALS AND WASTE ......................................................................................................... 3-1 VEHICLE WASHING ...................................................................................................................................... 3-1 ROUTINE INSPECTIONS AND MAINTENANCE OF STORMWATER BMPS ......................................................... 3-1 SPILL PREVENTION AND RESPONSE .............................................................................................................. 3-1 VEGETATION MAINTENANCE PLAN.............................................................................................................. 3-1 STORAGE AND USE OF FERTILIZERS, HERBICIDES, AND PESTICIDES ............................................................ 3-2 SNOW REMOVAL PLAN ................................................................................................................................ 3-2 NUTRIENT MANAGEMENT PLAN .................................................................................................................. 3-2

LONG-TERM OPERATION AND MAINTENANCE PLAN ................................................................... 4-1

4.1 STORMWATER MANAGEMENT SYSTEM COMPONENTS ................................................................................. 4-1 4.2 INSPECTION AND MAINTENANCE SCHEDULES .............................................................................................. 4-1 4.2.1 Conveyance Swales ............................................................................................................................ 4-1 4.2.2 Infiltration Basins .............................................................................................................................. 4-2 4.2.3 Stormwater Outfalls ........................................................................................................................... 4-2 4.3 ESTIMATED OPERATION AND MAINTENANCE BUDGET ................................................................................ 4-3 4.4 PUBLIC SAFETY FEATURES .......................................................................................................................... 4-3

FIGURES FIGURE 1: SITE PLANS APPENDICES APPENDIX A: OPERATION AND MAINTENANCE LOG APPENDIX B: LIST OF EMERGENCY CONTACTS APPENDIX C: PROPRIETARY SEPARATOR TECHNICAL MANUAL

Table of Contents

i

CEC Solar #1206, LLC Site Owner’s Manual Hopkinton, Massachusetts 283600RP002

1.0

INTRODUCTION

The Site Owner’s Manual complies with the Long-Term Pollution Prevention Plan (Standard 4) and the Long-Term Operation and Maintenance Plan (Standard 9) requirements of the 2008 Massachusetts Department of Environmental Protection (DEP) Stormwater Handbook. The Manual outlines source control and pollution prevention measures and maintenance requirements of stormwater best management practices (BMPs) associated with the proposed development.

Introduction

1-1

CEC Solar #1206, LLC Site Owner’s Manual Hopkinton, Massachusetts 283600RP002

2.0

SITE OWNER’S AGREEMENT

2.1

Operation and Maintenance Compliance Statement Site Owner:

Clean Energy Collective 146 West Boylston Street, 3rd Floor Worcester, MA 01606

Responsible Party:

Clean Energy Collective

Clean Energy Collective or their successors shall maintain ownership of the on-site stormwater management system as well as the responsibility for operation and maintenance during the post-development stages of the project. The site has been inspected for erosion and appropriate measures have been taken to permanently stabilize any eroded areas. All aspects of stormwater best management practices (BMPs) have been inspected for damage, wear and malfunction, and appropriate steps have been taken to repair or replace the system or portions of the system so that the stormwater at the site may be managed in accordance with the Stormwater Management Standards. Future responsible parties shall be notified of their continuing legal responsibility to operate and maintain the BMPs. The operation and maintenance plan for the stormwater BMPs is being implemented. ___________________________ Responsible Party Signature

___________ Date

2.2

Stormwater Maintenance Easements There are no off-site areas utilized for stormwater control, therefore no stormwater management easements are required. The Site Owner will have access to all stormwater practices for inspection and maintenance, including direct maintenance access by heavy equipment to structures requiring regular maintenance.

2.3

Record Keeping The Site Owner shall maintain a rolling log in which all inspections and maintenance activities for the past three years shall be recorded. The Operation and Maintenance Log includes information pertaining to inspections, repairs, and disposal relevant to the project’s stormwater management system. The Log is located in Appendix A. The Operation and Maintenance Log shall be made available to the Conservation Commission and the DEP upon request. The Conservation Commission and the DEP shall be allowed to enter and inspect the premises to evaluate and ensure that the responsible party complies with the maintenance requirements for each BMP.

Site Owner’s Agreement

2-1

CEC Solar #1206, LLC Site Owner’s Manual Hopkinton, Massachusetts 283600RP002

2.4

Training Employees involved in grounds maintenance and emergency response will be educated on the general concepts of stormwater management and groundwater protection. The Site Owner’s Manual will be reviewed with the maintenance staff. The staff will be trained on the proper course of action for specific events expected to be incurred during routine maintenance or emergency situations.

Site Owner’s Agreement

2-2

CEC Solar #1206, LLC Site Owner’s Manual Hopkinton, Massachusetts 283600RP002

3.0

LONG-TERM POLLUTION PREVENTION PLAN

In compliance with Standard 4 of the 2008 DEP Stormwater Management Handbook, this section outlines source control and pollution prevention measures to be employed on-site after construction. 3.1

Storage of Materials and Waste The site shall be kept clear of trash and debris at all times. Certain materials and waste products shall be stored inside or outside upon an impervious surface and covered, as required by local and state regulations.

3.2

Vehicle Washing No commercial vehicle washing shall take place on site.

3.3

Routine Inspections and Maintenance of Stormwater BMPs See Section 4.0 Long-Term Operation and Maintenance Plan, for routine inspection and maintenance requirements for all proposed stormwater BMPs.

3.4

Spill Prevention and Response A contingency plan shall be implemented to address the spill or release of petroleum products and hazardous materials and will include the following measures: 1. Equipment necessary to quickly attend to inadvertent spills or leaks shall be stored on-site in a secure but accessible location. Such equipment shall include but not be limited to the following: safety goggles, chemically resistant gloves and overshoe boots, water and chemical fire extinguishers, sand and shovels, suitable absorbent materials, storage containers and first aid equipment (i.e. Indian Valley Industries, Inc. 55-gallon Spill Containment kit or approved equivalent). 2. Spills or leaks shall be treated properly according to material type, volume of spillage and location of spill. Mitigation shall include preventing further spillage, containing the spilled material in the smallest practical area, removing spilled material in a safe and environmentally-friendly manner, and remediation of any damage to the environment. 3. For large spills, Massachusetts DEP Hazardous Waste Incident Response Group shall be notified immediately at (617) 792-7653 and an emergency response contractor shall be consulted.

3.5

Vegetation Maintenance Plan See attached Solar Facility’s Operation and Maintenance Plan (Appendix C). Vegetated stormwater BMPs will be maintained as outlined in Section 4.0.

Long-Term Pollution Prevention Plan

3-1

CEC Solar #1206, LLC Site Owner’s Manual Hopkinton, Massachusetts 283600RP002

3.6

Storage and Use of Fertilizers, Herbicides, and Pesticides Fertilizers, herbicides, and pesticides will not be used at the proposed facility.

3.7

Snow Removal Plan See attached Solar Facility’s Operation and Maintenance Plan.

3.8

Nutrient Management Plan A nutrient management plan is required if a Total Maximum Daily Load (TMDL) has been developed that indicates that use of fertilizers containing nutrients or other specific pollutants must be reduced. The proposed project is located within the Upper/Middle Charles River watershed, which has a final TMDL issued for Phosphorous. As indicated in Section 3.6, fertilizers, herbicides, and pesticides will not be used at the proposed facility. Runoff generated onsite will be routed to infiltration basins for peak flow mitigation and treatment.

Long-Term Pollution Prevention Plan

3-2

CEC Solar #1206, LLC Site Owner’s Manual Hopkinton, Massachusetts 283600RP002

4.0

LONG-TERM OPERATION AND MAINTENANCE PLAN

This section outlines the stormwater best management practices (BMPs) associated with the proposed stormwater management system and identifies the long-term inspection and maintenance requirements for each BMP. 4.1

4.2

Stormwater Management System Components The following table outlines the type and quantity of the BMPs and their general location. Please reference the site plan(s) provided in the Figures section for exact location. All basins are accessible for maintenance from within the array. BMP Type

Quantity

Location

Conveyance Swale

1

Along eastern perimeter, to Basin 1.

Infiltration Basin

3

Basin 1 (northeastern corner of Site), Basin 2 (center of Site), & Basin 3 (western perimeter of Site)

Inspection and Maintenance Schedules 4.2.1

Conveyance Swales Conveyance swales shall be inspected and maintained as outlined below: •

• •

•

Swales shall be inspected during the first three months after installation to ensure vegetation is adequate and slopes are not eroding. All eroded areas shall be repaired and revegetated. Thereafter, swales shall be inspected once per year. During the inspection, swales shall be checked for: o Slope integrity o Soil moisture o Vegetative health o Soil stability o Soil compaction o Soil erosion o Ponding o Sedimentation Corrective measures shall be taken immediately as warranted by the inspections. The swales shall be mowed at least once per year. The vegetation shall be maintained at a length of 3-6 inches to ensure the effectiveness of the vegetation in reducing flow velocity and removing pollutants. Clippings shall be removed after each mowing. Sediment and debris shall be removed manually at least once per year.

Long-Term Operation and Maintenance Plan

4-1

CEC Solar #1206, LLC Site Owner’s Manual Hopkinton, Massachusetts 283600RP002

• •

4.2.2

If any evidence of hydrocarbons is found during inspection, the material shall be immediately removed using absorbent pads or other suitable measures and legally disposed. The swales shall be reseeded as necessary to maintain a dense growth of vegetation.

Infiltration Basins Infiltration basins shall be inspected and maintained after major storm events (rainfall totals greater than 2.5 inches in 24 hours) during the first three months of operation and twice a year and when there are discharges through the outlet control structure thereafter. Additionally, all pretreatment BMPs shall be inspected in accordance with the minimal requirements specified for those practices and after all major storm events. Inspections shall include the following measures: •

• • • •

During and after major storm events, the length of time standing water remains in the basin shall be recorded. o If the time is greater than 72 hours, thoroughly inspect the basin for signs of clogging. o A corrective action plan shall be developed by a qualified professional to restore infiltrative function. The Site Owner shall take immediate action to implement these corrective measures. Examine the outlet structure for evidence of clogging or outflow release velocities that are greater than the design velocity. Identify areas of sediment accumulation, differential settlement, cracking, and erosion within the basin. Inspect embankments for leakage and tree growth. Examine the health of the vegetation within the basin and on the embankments.

Corrective measures shall be taken immediately as warranted by the inspections. If any evidence of hydrocarbons is found during inspection, the material shall be immediately removed using absorbent pads or other suitable measures and legally disposed. Preventative maintenance shall include the following activities: • Mow the buffer area and basin bottom and side slopes, if vegetated. • Remove trash, debris, and accumulated organic matter. • Remove clippings after mowing. 4.2.3

Stormwater Outfalls Flared end sections and associated riprap spillways shall be inspected at least once per year and after major storm events (rainfall totals greater than 2.5

Long-Term Operation and Maintenance Plan

4-2

CEC Solar #1206, LLC Site Owner’s Manual Hopkinton, Massachusetts 283600RP002

inches in 24 hours) to ensure that the stability of the outlet area is maintained. The outfall area shall be kept clear of debris such as trash, branches, and sediment. Repairs shall be made immediately if riprap displacement or downstream channel scour is observed. 4.3

Estimated Operation and Maintenance Budget An operations and maintenance budget was prepared to approximate the annual cost of the inspections required in compliance with the DEP Stormwater Management Policy. The table below estimates the annual cost to inspect and maintain each proposed BMP, based on the requirements in Section 4.2. BMP Type Water Quality Swale Infiltration Basin Riprap Spillway Stormwater Outfalls

4.4

# of BMPS 1 3 3 6

Annual O&M Cost (per BMP) 1 $400-$800 $200 - $400 $50-$100 $50-$100 Total

Total Cost $400-$800 $600-$1,200 $150-$300 $300-$600

Public Safety Features The facility contains a perimeter fence and gates that will be locked to prevent unauthorized entry into the facility.

1

Annual maintenance cost is based on estimate of the cost to complete all inspection and maintenance measures outlined in Section 4.2. For BMPs that require sediment removal at regular intervals (i.e. every 5 or 10 years), the annual cost includes the annual percentage of that cost.

Long-Term Operation and Maintenance Plan

4-3

Figures Figure 1: Site Plans

Appendices

Appendix A Operation and Maintenance Log

CEC Solar #1206, LLC Operation and Maintenance Log Hopkinton, Massachusetts 283600RP002

OPERATION AND MAINTENANCE LOG This template is intended to comply with the operation and maintenance log requirements of the 2008 DEP Stormwater Management Handbook. Copies of this log should be made for all inspections and kept on file for three years from the inspection date. Name/Company of Inspector: Date/Time of Inspection: Weather Conditions: (Note current weather and any recent precipitation events)

Stormwater BMP

Inspection Observations

Actions Required

Appendix B List of Emergency Contacts

Emergency Contacts Massachusetts DEP Hazardous Waste Incident Response Group (617)792-7653 Town of Hopkinton Department of Public Works 66 Fruit Street Hopkinton, MA 01748 (508)497-9740 Town of Hopkinton Fire Department 73 Main Street Hopkinton, MA 01748 (508)497-2323 Town of Hopkinton Police Department 74 Main Street Hopkinton, MA 01748 (508)497-3401

Appendix F Stormwater Pollution Prevention Plan

283600RP003

August 10, 2017

BEALS AND THOMAS, INC. Reservoir Corporate Center 144 Turnpike Road Southborough, MA 01772-2104

BEALS+THOMAS

Prepared by:

T F A R D

CEC Solar #1206, LLC c/o Clean Energy Collective 146 West Boylston Drive, 3rd Floor Worcester, MA 01606

Prepared for:

147 Lumber Street Hopkinton, Massachusetts

CEC Solar #1206, LLC

EPA Construction General Permit

SITE EVALUATION, ASSESSMENT AND PLANNING ............................................4

OPERATOR(S)/ SUBCONTRACTORS ................................................................................... 1 STORMWATER TEAM........................................................................................................ 2

CONTACT INFORMATION/RESPONSIBLE PARTIES ...........................................1

EROSION AND SEDIMENT CONTROL BMPS ........................................................15

ENDANGERED SPECIES CERTIFICATION.......................................................................... 12 HISTORIC PRESERVATION .............................................................................................. 12 SAFE DRINKING WATER ACT UNDERGROUND INJECTION CONTROL REQUIREMENTS.... 13 APPLICABLE STATE OR LOCAL PROGRAMS .................................................................... 14

COMPLIANCE WITH APPLICABLE FEDERAL & STATE REQUIREMENTS 12

Table of Contents

i

4.1 NATURAL BUFFERS OR EQUIVALENT SEDIMENT CONTROLS .......................................... 15 4.2 MINIMIZE DISTURBED AREA AND PROTECT NATURAL FEATURES AND SOIL ................. 17 4.2.1 Preserve Existing Vegetation .................................................................................... 17 4.2.2 Stockpiling Topsoil.................................................................................................... 17 4.3 PHASED CONSTRUCTION ACTIVITY................................................................................ 17 4.3.1 Phase I ...................................................................................................................... 17

4.0

3.1 3.2 3.3 3.4

3.0

T F A R D

2.1 PROJECT/SITE INFORMATION ........................................................................................... 4 2.1.1 Emergency-Related Projects ....................................................................................... 5 2.2 NATURE AND SEQUENCE OF CONSTRUCTION ACTIVITY ................................................... 5 2.2.1 Function of the Construction Activity ......................................................................... 5 2.2.2 Building Demolition .................................................................................................... 5 2.2.3 Agricultural Land........................................................................................................ 5 2.2.4 Estimated Project Dates ............................................................................................. 5 2.3 SOILS, SLOPES, VEGETATION, AND CURRENT DRAINAGE PATTERNS ............................... 7 2.4 CONSTRUCTION SITE ESTIMATES ..................................................................................... 7 2.5 DISCHARGE INFORMATION............................................................................................... 8 2.5.1 Description of Receiving Storm Sewer Systems .......................................................... 8 2.5.2 Receiving Waters ........................................................................................................ 8 2.5.3 Impaired Waters/ TMDLs ........................................................................................... 8 2.5.4 Tier 2, 2.5, or 3 Waters ............................................................................................... 9 2.6 UNIQUE SITE FEATURES AND SENSITIVE AREAS .............................................................. 9 2.7 CONSTRUCTION SUPPORT ACTIVITIES.............................................................................. 9 2.7.1 Support Activity Site Information................................................................................ 9 2.7.2 Support Activity Contact Information ......................................................................... 9 2.8 POTENTIAL SOURCES OF POLLUTION ............................................................................... 9 2.8.1 Potential Sources of Sediment .................................................................................... 9 2.8.2 Potential Sources of Non-Sediment Pollutants ........................................................... 9 2.9 SITE PLANS .................................................................................................................... 11

2.0

1.1 1.2

1.0

TABLE OF CONTENTS

283600RP003

CEC Solar #1206, LLC Stormwater Pollution Prevention Plan (SWPPP) Hopkinton, Massachusetts

GOOD HOUSEKEEPING BMPS ..................................................................................23

6.0

Table of Contents

ii

POST-CONSTRUCTION BMPS ...................................................................................31

5.1 MATERIAL HANDLING AND WASTE MANAGEMENT ....................................................... 23 5.1.1 Solid or Construction Waste Disposal ...................................................................... 24 5.1.2 Recycling ................................................................................................................... 24 5.1.3 Sanitary and Septic Waste ........................................................................................ 25 5.1.4 Hazardous Materials and Waste............................................................................... 25 5.2 ESTABLISH PROPER BUILDING MATERIAL STAGING AREAS .......................................... 26 5.3 DESIGNATE WASHOUT AREAS ....................................................................................... 26 5.3.1 Concrete Washout ..................................................................................................... 26 5.3.2 Applicators, Containers and Paint Washout ............................................................ 27 5.4 ESTABLISH PROPER EQUIPMENT/VEHICLE FUELING AND MAINTENANCE PRACTICES ... 28 5.5 ALLOWABLE NON-STORMWATER DISCHARGES AND CONTROL EQUIPMENT / VEHICLE WASHING ................................................................................................................................... 28 5.6 SPILL PREVENTION AND CONTROL PROCEDURES ........................................................... 29 5.7 FERTILIZER DISCHARGE RESTRICTIONS ......................................................................... 29 5.8 ANY ADDITIONAL BMPS ............................................................................................... 30 5.9 ALLOWABLE NON-STORMWATER DISCHARGE MANAGEMENT ...................................... 30

5.0

T F A R D

INSPECTIONS AND MAINTENANCE .......................................................................34

PERMANENT SEEDING .................................................................................................... 32

FINAL STABILIZATION ..............................................................................................32

DETENTION BASIN ......................................................................................................... 31 INFILTRATION BASIN ..................................................................................................... 31 BIORETENTION AREA ..................................................................................................... 31 GRASS DRAINAGE CHANNELS........................................................................................ 31 INFILTRATION TRENCH .................................................................................................. 31 POROUS PAVERS ............................................................................................................ 31 TREE BOX FILTER .......................................................................................................... 31 DEEP SUMP AND HOODED CATCH BASINS AND WATER QUALITY STRUCTURES............ 31

T F A R D

RECORDKEEPING AND TRAINING .........................................................................36

10.1 10.2 10.3 10.4

10.0

Table of Contents

iii

SIGNATURE, PLAN REVIEW, AND MAKING PLANS AVAILABLE ...................................... 38 NOTICE OF PERMIT COVERAGE ........................................................................................ 38 OWNER CERTIFICATION ................................................................................................. 39 OPERATOR CERTIFICATION ............................................................................................ 40

CERTIFICATION AND NOTIFICATION ..................................................................38

9.1 RECORDKEEPING............................................................................................................ 36 9.2 LOG OF CHANGES TO THE SWPPP ................................................................................. 36 9.3 TRAINING ....................................................................................................................... 36 9.3.1 Individual(s) Responsible for Training ..................................................................... 36 9.3.2 Description of Training Conducted .......................................................................... 37

9.0

8.1 INSPECTIONS .................................................................................................................. 34 8.1.1 Inspection Schedule and Procedures ........................................................................ 34 8.2 REDUCTIONS IN INSPECTION FREQUENCY ...................................................................... 35 8.3 CORRECTIVE ACTION LOG ............................................................................................. 35

8.0

7.1

7.0

6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8

283600RP003

283600RP003

4.3.2 Phase II ..................................................................................................................... 17 4.4 CONTROL STORMWATER FLOWING ONTO AND THROUGH THE PROJECT........................ 17 4.4.1 Earth Dike ................................................................................................................. 17 4.4.2 Grass Drainage Channels......................................................................................... 17 4.5 STABILIZE SOIL .............................................................................................................. 18 4.5.1 Temporary Stabilization............................................................................................ 18 4.5.2 Mulching ................................................................................................................... 18 4.5.3 Permanent Stabilization ............................................................................................ 19 4.5.4 Dust Control ............................................................................................................. 19 4.6 PROTECT SLOPES ........................................................................................................... 19 4.6.1 Erosion Control Blanket ........................................................................................... 19 4.7 PROTECT STORM DRAIN INLETS .................................................................................... 19 4.7.1 Filter Bags ................................................................................................................ 19 4.8 ESTABLISH PERIMETER CONTROLS AND SEDIMENT BARRIERS ...................................... 20 4.8.1 Erosion Control Barrier ........................................................................................... 20 4.8.2 Silt Fence .................................................................................................................. 20 4.9 PREVENT SOIL COMPACTION ......................................................................................... 21 4.9.1 Protect Proposed Infiltration Areas.......................................................................... 21 4.10 RETAIN SEDIMENT ON-SITE ........................................................................................... 21 4.10.1 Temporary Sediment Basins ................................................................................. 21 4.11 ESTABLISH STABILIZED CONSTRUCTION ENTRANCE/EXIT............................................. 22 4.12 DEWATERING PRACTICES .............................................................................................. 22 4.13 ADDITIONAL BMPS ....................................................................................................... 23 4.13.1 BMP Name ............................................................................................................ 23

CEC Solar #1206, LLC Stormwater Pollution Prevention Plan (SWPPP) Hopkinton, Massachusetts

CEC Solar #1206, LLC Stormwater Pollution Prevention Plan (SWPPP) Hopkinton, Massachusetts

CONSTRUCTION GENERAL PERMIT

NOI AND ACKNOWLEDGEMENT LETTER FROM EPA

INSPECTION REPORTS

CORRECTIVE ACTION LOG

SWPPP AMENDMENT LOG

SUBCONTRACTOR CERTIFICATIONS/ AGREEMENTS

GRADING AND STABILIZATION ACTIVITIES LOG

TRAINING LOG

DELEGATION OF AUTHORITY

ENDANGARD SPECIES DOCUMENTATION

HISTORIC PRESERVATION DOCUMENTATION

TEMPORARY SEDIMENT BASIN SIZING CALCULATION

NATURAL BUFFER EQUIVALENCY CALCULATIONS

APPENDIX C:

APPENDIX D:

APPENDIX E:

APPENDIX F:

APPENDIX G:

APPENDIX H:

APPENDIX I:

APPENDIX J:

APPENDIX K:

APPENDIX L:

APPENDIX M:

APPENDIX N:

APPENDIX O:

Table of Contents

SITE PLANS

APPENDIX B:

T F A R D

GENERAL LOCATION MAP

APPENDIX A:

LIST OF APPENDICES

iv

283600RP003

CEC Solar #1206, LLC Stormwater Pollution Prevention Plan (SWPPP) Hopkinton, Massachusetts

Company:

Worcester

146 West Boylston Drive

TBD

MA

City:

TBD ZIP Code:

TBD

Name:

Telephone: TBD

TBD

Company:

24-Hour Emergency Contact

TBD

TBD

01606

Contact Information/Responsible Parties

Site Work Contractor

State:

Area of Control:

City:

Email: TBD

TBD

Address:

Email: TBD

TBD ZIP Code:

ZIP Code:

Telephone: TBD

TBD

TBD

Name:

Subcontractor Name

Company:

Subcontractor(s)

Telephone: TBD

TBD

TBD

Address:

State:

Email: TBD

State:

T F A R D TBD

Contractor Name

Name:

Company:

Telephone: TBD

City:

Address:

Name:

Clean Energy Collective

OPERATOR(S)/ SUBCONTRACTORS

1.1 Operator(s)

CONTACT INFORMATION/RESPONSIBLE PARTIES

1.0

1

1.2

Southborough

Address:

City:

MA

ZIP Code:

01772

Email: [email protected]

State:

TBD

TBD

TBD

City:

Telephone:

TBD

TBD

TBD

Company:

Name:

Address:

Inspection Personnel

TBD ZIP Code:

TBD

TBD

Contact Information/Responsible Parties

Email: TBD

State:

Email: TBD

TBD ZIP Code:

Telephone:

Address: State:

TBD

City:

TBD

TBD

Name:

TBD

Company:

T F A R D

2

Personnel Responsible for Installation & Maintenance of Stormwater BMPs

Telephone: 508-366-0560

Christopher Hale-Sills

144 Turnpike Road

Name:

Beals and Thomas, Inc.

Company:

SWPPP Preparer

STORMWATER TEAM

TBD TBD

Address: City: Telephone:

TBD ZIP Code: Email: TBD

State:

TBD

Contact Information/Responsible Parties

T F A R D

TBD TBD

Name:

TBD

Company:

Personnel Responsible for Taking Corrective Actions

3

Longitude:

-71.5308°

ZIP Code:

WGS 84 Unknown

01606

Yes

No

Site Evaluation, Assessment and Planning

NPDES project or permit tracking number: TBD

4

Are you applying for permit coverage as a “federal operator” as defined in Appendix A of the 2012 CGP? Yes No

Is this project considered a federal facility?

______________________________________________________

If yes, provide the name of the Indian tribe associated with the area of Indian country (including the name of Indian reservation if applicable), or if not in Indian country, provide the name of the Indian tribe associated with the property:

Is the project located on Indian country lands, or located on a property of religious of Yes No cultural significance to an Indian tribe?

Horizontal Reference Datum: NAD 27 NAD 83

T F A R D

Method for Determining Latitude/Longitude: USGS Topographic Map (specify scale: _________) EPA Website GPS Other (please specify): _Google Earth_______

42.2009°

Latitude:

MA

Middlesex

State:

County or Similar Subdivision:

Hopkinton

147 Lumber Street

Project Street/Location:

City:

CEC Solar #1206, LLC

PROJECT/SITE INFORMATION

2.1

Project/Site Name:

SITE EVALUATION, ASSESSMENT AND PLANNING

2.0

2.2

Yes

No

T F A R D

Yes

No

Site Evaluation, Assessment and Planning

Estimated Project Start Date: TBD Estimated Project Completion Date: TBD

2.2.4 Estimated Project Dates

2.2.3 Agricultural Land Was the pre-development land used for agriculture?

If yes, do any of the structures being demolished have at least 10,000 square feet Yes No of floor space?

2.2.2 Building Demolition Will there be demolition of any structure built or renovated before January 1, 1980? Yes No

Highway or Road Construction Other (please specify):_Solar Energy__

Institutional

Industrial

Multi-Family Residential

Utility

Commercial

Single-Family Residential

Function of the construction activity:

The project consists of the construction of a 6 MW solar energy facility within existing agricultural fields as well as in currently wooded areas.

2.2.1 Function of the Construction Activity

NATURE AND SEQUENCE OF CONSTRUCTION ACTIVITY

5

If yes, document the cause of the public emergency (e.g., natural disaster, extreme flooding conditions), information substantiating its occurrence (e.g., state disaster declaration), and a description of the construction necessary to reestablish effective public services:

Is this project in response to a public emergency?

2.1.1 Emergency-Related Projects

Construction Activity and BMP Descriptions

Before any site grading activities begin 1. Stake Limit of Construction. Workers shall be informed that no construction activity is to occur beyond this limit at any time. 2. Delineate the limit of the natural buffer to be maintained with flags, tape or other similar device. 3. Clear vegetation as necessary within the limits of construction. A stockpile of wood chips from tree cutting shall be left on site for stabilization. 4. Grub the areas where silt fence is required, removing stumps and roots as necessary. The existing ground surface shall be disturbed as little as possible prior to the start of construction. 5. Install silt fence and straw bales as shown on the plans. An adequate stockpile of erosion control materials shall be on site at all times for emergency or routine replacement and shall include materials to repair silt fences, straw bales, or any other devices planned for use during construction. 6. Construct stabilized construction exits. 7. Construct staging and materials storage area. 8. Install temporary sanitary facilities and dumpsters.

Date Start –Date End

Date Start –Date End

Site Evaluation, Assessment and Planning

6

Site grading 1. Begin site clearing and grubbing operations. 2. Commence excavation of stormwater management basins to act as temporary sedimentation basins during construction. 3. Commence construction of temporary drainage channels to direct runoff to sedimentation basin(s) during construction. Check dams shall be installed along the temporary drainage channels to reduce velocities and collect sediment. 4. Begin overall site grading and topsoil stripping. 5. Establish topsoil stockpile. 6. Install silt fences around stockpile and cover stockpiles. 7. Disturbed areas where construction will cease for more than 14 days shall be stabilized with erosion controls. Array Construction 1. Begin construction of Array. 2. Implement winter stabilization procedures.

T F A R D

Estimated Timeline of Activity Date Start –Date End

2.4

2.3

Final stabilization and landscaping 1. Convert temporary sediment basin(s) to (a) permanent infiltration basins. 2. Remove all temporary control BMPs and stabilize any areas disturbed by their removal with erosion controls 3. Prepare final seeding and landscaping. 4. Monitor stabilized areas until final stabilization is reached.

Total property area:

CONSTRUCTION SITE ESTIMATES

Site Evaluation, Assessment and Planning

TBD acres 7

Vegetation: The solar array is proposed within an area that is comprised of predominantly woodland vegetation. There is a portion of the property that is partially developed, and occupied by a single-family residence.

Drainage Patterns: The array is approximately centered on a high-point. Runoff from the site drains to the east and to the west. There are onsite bordering vegetated wetlands (BVW) at the eastern perimeter of the site as well as a potential vernal pool (PVP) and associated isolated vegetated wetland (IVW) at the southeastern quadrant. There is also a BVW at the western perimeter of the site (adjacent to Lumber Street). The resource areas at northeastern and western portions of the site ultimately flow to the north. The southeastern potion of the site (including the PVP and IVW) flows to the east and south.

Slopes: Slopes on site vary from 0% to 15%

T F A R D

Canton Fine Sandy Loam is a very deep, well drained soil on glaciated uplands. The typical soil profile is comprised of layers of fine sandy loam over gravelly fine sandy loam, over gravelly loamy sand. NRCS classifies these soils as Hydrologic Soil Group (HSG) “A” (extremely bouldery) & “B” (extremely stony). Narragansett Silt Loam, is a deep, well drained soil on glacial till plains and ground moraine. The typical soil profile is comprised of layers of silt loam over very gravelly loamy sand. NRCS classifies this soil as HSG “A”. Ridgebury Fine Sandy Loam, a very deep, poorly drained to somewhat poorly drained soil on glacial till uplands. The typical soil profile is comprised of layers of fine sandy loam over loamy fine sand, sand, and gravelly coarse sand. NRCS classifies this soil as HSG “D”.

Soil type(s): The Natural Resources Conservation Service (NRCS) Web Soil Survey lists the on-site soils as Canton Fine Sandy Loam, Narragansett Silt Loam, and some areas of Ridgebury Fine Sandy Loam.

SOILS, SLOPES, VEGETATION, AND CURRENT DRAINAGE PATTERNS

Date Start –Date End

2.5

TBD acres TBD % TBD TBD % TBD

Maximum area to be disturbed at one time:

Percentage impervious area before construction:

Runoff coefficient before construction:

Percentage impervious area after construction:

Runoff coefficient after construction:

2.8

Does your project/site discharge stormwater into a Municipal Separate Storm Sewer System (MS4)? Yes No

Yes

No

Yes

No

Site Evaluation, Assessment and Planning

List the pollutant(s) for which there is a TMDL: Phosphorus

8

If yes, list the title of the TMDL document: Total Maximum Daily Load for Nutrients in the Upper/Middle Charles River, Massachusetts

Has a TMDL been completed?

Describe the method(s) used to determine whether or not your project site discharges to an impaired water: Mass GIS Oliver mapping.

If yes, list the pollutant(s) causing the impairment: Phosphorus

Has the surface water been listed as “impaired?”

2.5.3 Impaired Waters/ TMDLs

Portions of the site drain to Echo Lake, which is a tier 2.5, or public water supply, which feeds the Charles River. Other portions of the site drain to Icehouse Pond, then Indian Brook, which feeds the Hopkinton Reservoir. A third portion of the site drains to Wildcat Pond, and then the Charles River.

2.5.2 Receiving Waters

2.7

2.6

2.5.1 Description of Receiving Storm Sewer Systems

T F A R D

DISCHARGE INFORMATION

TBD acres

Total construction site area to be disturbed:

Tier 2.5

Yes

Tier 3

No

T F A R D

Clearing and grubbing operations Grading and site excavation operations Vehicle tracking Topsoil stripping and stockpiling Landscaping operations

[2]

Fertilizer

Pesticides

Material/ Chemical

x

x

x

x

Chlorinated hydrocarbons, organophosphates, carbamates, arsenic Nitrogen, phosphorous

Various colored to colorless liquid, powder, pellets, or grains Liquid or solid grains

9

Herbicides used for noxious weed control Newly seeded areas

Location[1]

Site Evaluation, Assessment and Planning

Stormwater Pollutants

Physical Description

Combined Staging Area — small fueling activities, minor equipment maintenance, sanitary facilities, and hazardous waste storage. Materials Storage Area — general building materials, solvents, adhesives, paving materials, paints, aggregates, trash, and so on. Construction Activity — paving, curb/gutter installation, concrete pouring/mortar/stucco, and building construction Concrete Washout Area

2.8.2 Potential Sources of Non-Sediment Pollutants

x x x x x

2.8.1 Potential Sources of Sediment

POTENTIAL SOURCES OF POLLUTION

CONSTRUCTION SUPPORT ACTIVITIES Construction support activities are not required for the project.

There are onsite bordering vegetated wetlands (BVW) at the eastern perimeter of the site as well as a potential vernal pool (PVP) and associated isolated vegetated wetland (IVW) at the southeastern quadrant. There is also a BVW at the western perimeter of the site (adjacent to Lumber Street). The resource areas at northeastern and western portions of the site appear to ultimately flow to the north.

UNIQUE SITE FEATURES AND SENSITIVE AREAS

If yes specify which Tier the surface water is designated as: Tier 2

Is this surface water designated as a Tier 2, 2.5 or 3 water?

2.5.4 Tier 2, 2.5, or 3 Waters

Stoddard solvent, petroleum distillates, arsenic, copper, chromium

Naphtha

Metal oxides, stoddard solvent, talc, calcium carbonate, arsenic

Polymers, epoxies

Oil, petroleum distillates

Perchloroethylene, methylene chloride, trichloroethylene, petroleum distillates

Benzene, ethyl benzene, toluene, xylene, MTBE

Petroleum distillate, oil & grease, naphthalene, xylenes

Coal oil, petroleum distillates

Colorless, pale brown or pink petroleum hydrocarbon

Clear, blue-green to yellow liquid

Pale yellow liquid petroleum hydrocarbon

Gasoline

Diesel Fuel

Kerosene

Curb and gutter, walkways Timber pads and building construction Leaks or broken hoses from equipment Secondary containment/staging area Secondary containment/staging area Secondary containment/staging area Leaks or broken hoses from equipment

Building construction

Streets, parking areas, and roofing Building construction

No equipment cleaning allowed in project limits

Antifreeze/ coolant

Clear green/yellow liquid

Site Evaluation, Assessment and Planning

10

Ethylene glycol, propylene glycol, heavy metals (copper, lead, zinc) Sanitary Bacteria, parasites, and Various colored liquid Staging area toilets viruses [1] Area where material/chemical is used on-site. [2] Use of fertilizers containing nitrogen and/ or phosphorus in ratios greater than recommended by the manufacture must be documented.

Mineral oil

Brown oily petroleum hydrocarbon

Hydraulic oil/fluids

T F A R D

Clear amber or dark brown liquid

Various colored liquids

Paints

Wood preservatives

White or yellow liquid

Glue/ adhesives

Creamy white liquid

Black solid

Asphalt

Curing compounds

Colorless, blue, or yellow-green liquid

Cleaning solvents

2.9

T F A R D

See Appendix B: Site Plans

Site Evaluation, Assessment and Planning

Areas of federally-listed critical habitat for endangered or threatened species

11

Locations where polymers, flocculants, or other treatment chemicals will be used and stored

Locations of all pollutant-generating activities

Locations of storm drain inlets and stormwater control measures on the site and in the immediate vicinity of the site

Locations where stormwater discharges or allowable non-stormwater to surface water(s)

Boundary lines of any natural buffers,

Location of all waters of the U.S., including wetlands on or near the site. Indicate if water bodies are listed as impaired, or are identified as Tier 2, 2.5 or 3 waters.

Locations of off-site material, waste, borrow, or equipment storage areas

Locations [and timing] of stabilization measures

Location(s) of sediment, soil or other construction materials will be stockpiled

Locations of major structural and non-structural BMPs identified in the SWPPP

Natural features to be preserved

Direction(s) of stormwater flow and approximate slopes before and after major grading activities

Areas of soil disturbance and areas that will not be disturbed

Delineation of construction phasing, if applicable

These Site Plans include:

The Topographic Plan shows the undeveloped site and its current features. The Site Plans show the developed site.

SITE PLANS

3.2

ENDANGERED SPECIES CERTIFICATION

3.1

Compliance with Applicable Federal & State Requirements

If yes, provide documentation of the basis for your determination.

12

Step 3 If you answered no in Step 2, has it been determined that the installation of subsurface earth-disturbing stormwater controls will have no effect on historic properties? Yes No

Step 2 If you answered yes in Step 1, have prior surveys or evaluations conducted on the site already determined that historic properties do not exist, or that prior disturbances at the site have precluded the existence of historic properties? Yes No

Step 1 Will stormwater controls that require subsurface earth disturbance be installed on the site? Yes No

HISTORIC PRESERVATION

If yes, describe or refer to documentation that determines the likelihood of an impact on the identified species and/or habitat and the steps taken to address that impact.

If yes, describe the species and/or critical habitat:

T F A R D

Additionally, the NHESP Northern Long-eared Bat Locations in Massachusetts map, last updated March 24, 2016 was reviewed and it was determined that the Project does not occur within 0.25 miles of a known winter hibernacula or within a 150-foot radius of a known maternity roost tree. Therefore, no further review of potential impacts to Northern Long-eared Bat is required pursuant to the MESA.

Describe how this determination was made: The MASSGIS NHESP Priority Habitat of Rare Species Layer, Updated September, 2008, indicates that no priority habitat of rare species are located within the project site.

Are endangered or threatened species and critical habitats on or near the project area? Yes No

COMPLIANCE WITH APPLICABLE FEDERAL & STATE REQUIREMENTS

3.0

3.3

T F A R D

Compliance with Applicable Federal & State Requirements

13

If yes, attach documentation of contact between you and the applicable state agency or EPA Regional Office responsible for implementing the requirements for underground injection wells in the Safe Drinking Water Act and EPA’s implementing regulations at 40 CFR Parts 144-147.

Drywells, seepage pits, or improved sinkholes (if stormwater is directed to any bored, drilled, driven shaft or dug hole that is deeper than its widest surface dimension, or has a subsurface fluid distribution system)

Commercially manufactured pre-cast or pre-built proprietary subsurface detention vaults, chambers, or other devices designed to capture and infiltrate stormwater flow

Infiltration trenches (if stormwater is directed to any bored, drilled, driven shaft or dug hole that is deeper than its widest surface dimension, or has a subsurface fluid distribution system)

Do you plan to install any of the following controls?

SAFE DRINKING WATER ACT UNDERGROUND INJECTION CONTROL REQUIREMENTS

Other:

No agreement has been reached regarding measures to mitigate effects to historic properties from the installation of stormwater controls.

Written indication that adverse effects to historic properties from the installation of stormwater controls can be mitigated by agreed upon actions.

If no, no further documentation is required. If yes, describe the nature of their response and include documentation in the Appendix:

Step 4 If you answered no in Step 3, did the State Historic Preservation Officer (SHPO), Tribal Historic Preservation Office (THPO), or other tribal representative (whichever applies) respond within 15 calendar days to indicate whether the subsurface earth disturbances caused by the installation of stormwater controls affect historic properties? Yes No

3.4

Compliance with Applicable Federal & State Requirements

T F A R D

14

A plan to control construction-related impacts, including erosion, sedimentation, and other pollutant sources during construction and land disturbance activities (construction period erosion, sedimentation, and pollution prevention plans) shall be developed and implemented.

NATURAL BUFFERS OR EQUIVALENT SEDIMENT CONTROLS

Natural Buffers or Equivalent Sediment Controls Minimize disturbed area and protect natural features and soil Control stormwater flowing onto and through the project Stabilize soils Protect slopes Establish perimeter controls and sediment barriers Retain sediment on-site and control dewatering practices Establish stabilized construction exits

Good Housekeeping BMPs

15

It is infeasible to provide and maintain an undisturbed natural buffer of any size, therefore erosion and sediment controls will be implemented that achieve the sediment load reduction equivalent to a 50-foot undisturbed natural buffer. The estimated

Description of Controls: Provide a description of the additional erosion and sediment controls proposed, including the model or other tool used to estimate the sediment load reductions and the results from the calculation.

An undisturbed natural buffer of xx-feet will be provided along with supplemental erosion and sediment controls, which in combination achieves the sediment load reduction equivalent to a 50-foot undisturbed natural buffer. The estimated sediment removal calculations are included in the appendixes of this report and have been calculated using the applicable tables included in Appendix G of the 2012 Construction General Permit or site-specific calculations were performed to estimate the sediment removal of a 50-buffer zone and the efficiency of the reduced buffer zone and supplemental erosion control measures.

A 50-foot undisturbed natural buffer will be maintained. The 50-foot buffer is shown on the attached site plans and will be clearly marked off with flags, tape, or a similar marking device prior to the commencement of earth disturbing activities.

If yes, check the compliance alternative that applies:

Are there any surface waters located within 50 feet of your construction disturbances that receive stormwater discharges from the site? Yes No

4.1

x x x x x x x x

This SWPPP contains a listing of the erosion and sediment control best management practices (BMPs) that will be implemented to control pollutants in stormwater discharges. The BMPs are categorized under one of the areas of BMP activity as described below:

This SWPPP complies with the requirements of Standard 8 of the Massachusetts Department of Environmental Protection Stormwater Handbook, which states:

EROSION AND SEDIMENT CONTROL BMPS

4.0

APPLICABLE STATE OR LOCAL PROGRAMS

Good Housekeeping BMPs

16

Buffer disturbances will occur for the construction of a water-dependent structure or water access area (e.g., pier, boat ramp, and trail).

Buffer disturbances are authorized under a CWA Section 404 permit.

Alternative 2: A sediment discharge risk evaluation has been prepared and is included in the appendices of this report.

Alternative 1: A [select one: 50-foot buffer, a buffer <50 feet and > 30 has been provided with double perimeter controls buffer less than 30-feet has been provided with double perimeter controls with 7-day site stabilization requirements has been provided.] Provide a description on how the controls will comply with the CGP requirements.

The project qualifies as “small residential lot” construction, and complies with:

For a “linear project,” site constraints (e.g., limited right-of-way) make it infeasible for the site to meet any of the CGP Part 2.1.2.1.a compliance alternatives

No natural buffer exists due to preexisting development disturbances, such as impervious surfaces or structures that were constructed prior to the initiation of planning for this project.

There is no discharge of stormwater to surface waters through the area between the disturbed portions of the site and any surface waters located within 50 feet of the site. This includes situations where control measures have been implemented such as a berm or other barrier that will prevent such discharges.

T F A R D

The project qualifies for one of the exceptions in Part 2.1.2.1.e. of the 2012 Construction General Permit. Specifically:

Description: Include rationale for why a natural buffer cannot be maintained. Provide a description of the additional erosion and sediment controls proposed, including the model or other tool used to estimate the sediment load reductions and the results from the calculation. Include the estimated sediment removal rate from a natural 50-buffer and the proposed controls.

sediment removal calculations are included in the appendixes of this report and have been calculated using the applicable tables included in Appendix G of the 2012 Construction General Permit or site-specific calculations were performed to estimate the sediment removal of a 50-buffer zone and the efficiency of the reduced buffer zone and supplemental erosion control measures.

4.3

4.2

Design Specifications

Maintenance and Inspection:

Installation Schedule:

Description:

Good Housekeeping BMPs

17

A grass drainage channel shall be installed at location, as indicated on the site plans. The channel shall convey runoff to storm drain inlets and temporary sediment basins, as appropriate or at locations shown on plans. Some grass drainage channels shall remain as a permanent stormwater structure after construction is complete. The grass drainage channel shall be installed after clearing and grubbing operations are completed at the site. The channel shall be inspected weekly and immediately after storm events for erosion and structural failures. Before vegetation has been established in the channel, inspect erosion control blankets, embankments, and beds for erosion and accumulation of debris and sediment. Remove debris, sediment, and repair erosion control blankets, fiber rolls and embankments immediately.

4.3.1 Grass Drainage Channels

CONTROL STORMWATER FLOWING ONTO AND THROUGH THE PROJECT

Topsoil stripped from the immediate construction area shall be stockpiled as identified on the Site Plans and Sitework Specifications or as approved by the SWPPP preparer. Stockpiles shall be located outside of any natural buffers and away from any stormwater conveyances, drain inlets, and areas where stormwater flow is concentrated. Installation Topsoil stockpiles shall be established during grading activities. Schedule: The silt fence and temporary erosion controls shall be installed immediately after the stockpile has been established. For piles that will be unused for 14 or more days provide cover over the stockpile or temporary stabilization to avoid direct contract with precipitation and wind. Install a sediment barrier along all downgradient perimeter areas of stockpiles. Maintenance The area shall be inspected weekly for erosion and immediately after and storm events. Areas on or around the stockpile that have eroded shall Inspection: be stabilized immediately with erosion controls. See following Silt Fence section for Maintenance and inspection procedures.

Description:

4.2.1 Stockpiling Topsoil

MINIMIZE DISTURBED AREA AND PROTECT NATURAL FEATURES AND SOIL

4.4

Initiation of temporary vegetative cover shall occur immediately where construction will cease for more that 7 days. It shall be established using hydroseeding for areas of exposed soil (including stockpiles). Temporary stabilization measures shall be initiated immediately where construction activities will temporarily cease for more than 14 days. Stabilized areas shall be inspected weekly and after storm events until a dense cover of vegetation has become established. If failure is noticed at the seeded area, the area shall be reseeded, fertilized, and mulched immediately.

Maintenance and Inspection:

Good Housekeeping BMPs

18

Hydromulching shall provide immediate protection to exposed soils during short periods of disturbance. Hydromulch shall also be applied in areas that have been seeded for temporary or permanent stabilization. Hydromulch shall be applied to exposed soils during short periods of construction and seeded areas. Mulched areas shall be inspected weekly and after storm events to check for movement of mulch or erosion. If washout, breakage, or erosion occurs, the surface shall be repaired, and new mulch shall be applied to the damaged area.

T F A R D

Installation Schedule:

Description:

4.4.2 Mulching

Maintenance and Inspection:

Installation Schedule:

Description:

4.4.1 Temporary Stabilization

STABILIZE SOIL

1. The channel shall have a positive drainage to convey runoff to the storm drain inlets and temporary sediment basins.

Maintenance and Inspection:

Installation Schedule:

Description:

4.4.4 Dust Control

Initiation of permanent stabilization measures shall occur immediately after the final design grades are achieved and earth moving activities cease. Native species of plants shall be used to establish vegetative cover on exposed soils. Permanent stabilization shall be completed in accordance with the procedures outlined in the Final Stabilization section of this report. Portions of the site where construction activities have permanently ceased shall be stabilized, as soon as possible. All seeded areas shall be inspected weekly during construction activities and after storm events until a dense cover of vegetation has been established. If failure is noticed at the seeded area, the area shall be reseeded, fertilized, and mulched immediately. Care shall be taken to avoid compacting newly placed topsoil. After construction is completed at the site, permanently stabilized areas shall be monitored until final stabilization is reached.

Good Housekeeping BMPs

19

Dust from the site shall be controlled by using a mobile pressure-type distributor truck to apply water to disturbed areas. The mobile unit shall apply water at a rate of 300 gallons per acre and minimized as necessary to prevent runoff and ponding. Dust control shall be implemented as needed once site grading has been initiated and during windy conditions (forecasted or actual wind conditions of 20 mph or greater) while site grading is occurring. Spraying of water shall be performed no more than three times a day during the months of May–September and once per day during the months of October–April or whenever the dryness of the soil warrants it. At least one mobile unit shall be available at all times to distribute water to control dust on the project area. Each mobile unit shall be equipped with a positive shutoff valve to prevent over watering of the disturbed area.

T F A R D

Maintenance and Inspection:

Installation Schedule:

Description:

4.4.3 Permanent Stabilization

4.5

Good Housekeeping BMPs

20

Temporary Entrenched silt fence shall be installed to decrease the velocity of sheet flows and intercept and detain small amounts of sediment from disturbed areas. Installation Schedule: Silt fence shall be installed prior to clearing and grubbing. Maintenance and Silt fence shall be inspected weekly, following storms, and Inspection: daily during rainy periods. Damaged fencing shall be replaced. Concentrated flows shall be intercepted and rerouted. Sediment accumulations shall be removed when reaching a depth of 6-inches. Deteriorated fencing material shall be replaced. Used fencing shall be properly disposed of.

Permanent Description:

4.5.2 Silt Fence

T F A R D

Temporary An erosion control barrier, consisting of entrenched straw bales, straw wattles, compost socks and siltation fencing, shall be installed along the downgradient side of the proposed project to decrease the velocity of sheet flows and intercept and detain small amounts of sediment from disturbed areas. Installation Schedule: Erosion Control Barrier shall be installed prior to clearing and grubbing. Maintenance and Erosion Control Barrier shall be inspected weekly, Inspection: following storms, and daily during rainy periods. Damaged fencing shall be replaced. Concentrated flows shall be intercepted and rerouted. Sediment accumulations shall be removed when reaching a depth of 6-inches, or one-half of the above ground height of the barrier, whichever is less. Deteriorated fencing material shall be replaced. Used fencing shall be properly disposed of.

Permanent Description:

4.5.1 Erosion Control Barrier

ESTABLISH PERIMETER CONTROLS AND SEDIMENT BARRIERS

4.7

4.6

Good Housekeeping BMPs

21

Temporary Temporary sediment basins are located throughout the site between construction and wetland resource areas. These basins provide 3,600 cubic feet of storage per acre drained, as required by the EPA. Refer to the Temporary Sediment Basin Sizing Calculation located in Appendix K. Several temporary sediment basins will be utilized as sediment forebays following construction. Installation Schedule: Temporary Sediment Basins shall be installed during grading activities. Maintenance and Temporary Sediment Basins shall be inspected weekly and Inspection: following storms. Sediment shall be removed when it reaches a depth of one foot, or half the design capacity whichever is less. Damage to basin embankments and slopes shall be repaired.

Permanent Description:

4.7.1 Temporary Sediment Basins

RETAIN SEDIMENT ON-SITE

T F A R D

Temporary An erosion control barrier, consisting of entrenched straw bales and siltation fencing, shall be installed around the perimeter of all proposed infiltration areas to prevent construction vehicles from impacting the area, to decrease the velocity of sheet flows and intercept, and detain small amounts of sediment from disturbed areas. Installation Schedule: The erosion control barrier shall be installed after clearing and grubbing. Maintenance and Silt fence shall be inspected weekly, following storms, and Inspection: daily during rainy periods. Damaged fencing shall be replaced. Concentrated flows shall be intercepted and rerouted. Sediment accumulations shall be removed when reaching a depth of 6-inches. Deteriorated fencing material shall be replaced. Used fencing shall be properly disposed of.

Permanent Description:

4.6.1 Protect Proposed Infiltration Areas

PREVENT SOIL COMPACTION

4.9

4.8

Description:

DEWATERING PRACTICES

x x

Good Housekeeping BMPs

22

Visible floating solids or foam shall not be discharged; An oil-water separator or suitable filtration device (such as a cartridge filter) that is designed to remove oil, grease, or other products if dewatering water is found to contain these materials shall be used;

All groundwater or stormwater discharged from excavations, trenches, foundations, vaults, or other similar point shall be treated by sediment basins, sediment traps, sediment socks, dewatering tanks, tube settlers or filtration systems specifically designed to remove sediment from the excavations. All dewatering practices shall conform to the following:

T F A R D

Temporary Temporary gravel or crushed stone construction entrances/exits or other means shall be used to minimize off-site movement of soil with vehicles. Construction access points shall be maintained to minimize tracking of soil onto public roads and existing parking lots to remain. If the rock entrance is not working to keep streets clean, then install wheel wash, sweep streets, or wash streets if wash water can be collected. Installation Schedule: Stabilized construction entrance shall be installed prior to clearing and grubbing. Maintenance and Stabilized construction entrances shall be inspected daily. Inspection: Gravel or crushed stone shall be added if the pad is no longer in accordance with the specifications. If the rock entrance is not working to keep streets clean, then install wheel wash, sweep streets, or wash streets if wash water can be collected. When sediment has been tracked off of the site, it shall be removed by the end of the same working day, or by the end of the next working day if track-out occurs on a non work day. Remove sediment by sweeping, shoveling or vacuuming roadways were sediment has been tracked-out.

Permanent Description:

ESTABLISH STABILIZED CONSTRUCTION ENTRANCE/EXIT

GOOD HOUSEKEEPING BMPS

5.1

Material Handling and Waste Management Establish Proper Material Staging Areas Designate Washout Areas Establish Proper Equipment/Vehicle Fueling and Maintenance Practices Allowable Non-Stormwater Discharges and Control Equipment/Vehicle Washing Spill Prevention and Control Plan

Good Housekeeping BMPs

23

Several management procedures and practices are proposed to prevent and/or reduce the discharge of pollutants to stormwater from solid or liquid wastes that will be generated at the site. These measures are grouped into the following categories: (1) solid or construction waste disposal, (2) recycling, (3) sanitary and septic waste, and (4) hazardous materials.

MATERIAL HANDLING AND WASTE MANAGEMENT

x x x x x x

This SWPPP contains a listing of the good housekeeping best management practices (BMPs) that shall be implemented to control pollutants in stormwater discharges during construction-related work. The BMPs are categorized below:

5.0

Maintenance and Inspection:

Installation Schedule:

To the extent feasible, utilize vegetated, upland areas of the site to infiltrate dewatering water before discharge. In no case will surface waters be considered part of the treatment area; x Velocity dissipaters shall be installed at all points where dewatering activities are discharged to the surface. x With backwash water, either haul it away for disposal or return it to the beginning of the treatment process; and x Replace and clean the filter media used in dewatering devices when the pressure differential equals or exceeds the manufacturer’s specifications. Install settling or filtration methods prior to commencing dewatering. Engineer is required to provide or approve settling of filtration method design prior to installation. Settling of filtration controls shall be inspected weekly and following storms. Sediment shall be removed when it reaches a depth of one foot, or half the design capacity whichever is less.

x

Installation Schedule: Maintenance and Inspection:

Description:

5.1.2 Recycling

Good Housekeeping BMPs

24

Wood pallets, cardboard boxes, and other recyclable construction scraps shall be disposed of in a designated dumpster for recycling. The dumpster shall have a secure watertight lid, be placed away from stormwater conveyances and drains and meet all local and state solid-waste management regulations. Only solid recyclable construction scraps from the site shall be deposited in the dumpster. All personnel shall be instructed regarding the correct procedure for disposal of recyclable construction scraps. Notices that state these procedures shall be posted in the office trailer, and the individual who manages day-to-day site operations shall be responsible for seeing that these procedures are followed. Designated recycling dumpsters shall be installed once the area has been established. The recycling dumpster shall be inspected weekly and immediately after storm events. The recycling dumpster shall be emptied weekly and taken to an approved recycling center. If recyclable

T F A R D

All waste materials shall be collected and disposed of into metal trash dumpsters in the materials storage area. Dumpsters shall have a secure watertight lid, be placed away from stormwater conveyances and drains, and meet all federal, state, and municipal regulations. Only trash and construction debris from the site shall be deposited in the dumpster. No construction materials shall be buried on-site unless authorized by a program for recycling/beneficial use. All personnel shall be instructed regarding the correct disposal of trash and construction debris. Notices that state these practices shall be posted in the office trailer and the individual who manages daytoday site operations shall be responsible for seeing that these practices are followed. Installation Trash dumpsters shall be installed once the materials storage area Schedule: has been established. Maintenance The dumpsters shall be inspected weekly and immediately after and storm events. The dumpsters shall be emptied weekly and taken to Inspection: an approved landfill or recycling facility. If trash and construction debris are exceeding the dumpsters’ capacity, the dumpsters shall be emptied more frequently. Waste container lids shall be closed when not in use and at the end of the business day. For waste containers that do not have lids, provide cover or a similarly effective means to minimize the discharge of pollutants.

Description:

5.1.1 Solid or Construction Waste Disposal

T F A R D

Temporary sanitary facilities (portable toilets) shall be provided at the site throughout the construction phase. The portable toilets shall be located in the staging area, away from concentrated flow paths and traffic flow. The portable toilets shall be brought to the site once the staging area has been established. All sanitary waste shall be collected from the portable facilities on a regular basis. The portable toilets shall be inspected weekly for evidence of leaking holding tanks. Toilets with leaking holding tanks shall be removed from the site and replaced with new portable toilets.

Installation Schedule: Maintenance and Inspection:

Description:

Good Housekeeping BMPs

25

All hazardous waste materials such as oil filters, petroleum products, paint, and equipment maintenance fluids shall be stored in structurally sound and sealed shipping containers, within the hazardous materials storage area. Hazardous waste materials shall be stored in appropriate and clearly marked containers and segregated from other non-waste materials. Secondary containment shall be provided for all waste materials in the hazardous materials storage area and shall consist of commercially available spill pallets. Additionally, all hazardous waste materials shall be disposed of in accordance with federal, state, and municipal regulations. Hazardous waste materials shall not be disposed of into the on-site dumpsters. All personnel shall be instructed regarding proper procedures for hazardous waste disposal. Notices that state these procedures shall be posted in the office trailer and the individual who manages day-to-day site operations shall be responsible for seeing that these procedures are followed. Shipping containers used to store hazardous waste materials shall be installed once the site materials storage area has been installed. The hazardous waste material storage areas shall be inspected weekly and after storm events. The storage areas shall be kept clean, well organized, and equipped with ample cleanup supplies as appropriate for the materials being stored. Material safety data sheets, material inventory, and emergency contact numbers shall be maintained in the office trailer.

5.1.4 Hazardous Materials and Waste

Installation Schedule: Maintenance and Inspection:

Description:

5.1.3 Sanitary and Septic Waste

construction wastes are exceeding the dumpsters’ capacity, the dumpsters shall be emptied more frequently.

5.3

5.2

All fertilizers, herbicides, insecticides and pesticides shall be stored in accordance with local, state, and federal regulations. At a minimum these materials shall be covered with plastic sheeting or a temporary roof to prevent contact with rainwater.

T F A R D

All hazardous-waste materials such as oil filters, petroleum products, paint, and equipment maintenance fluids shall be stored in structurally sound and sealed containers under cover within the storage area.

Construction equipment and maintenance materials shall be stored at the combined staging area and materials storage areas. A watertight shipping container shall be used to store hand tools, small parts, and other construction materials. Nonhazardous building materials such as packaging material (wood, plastic, and glass), and construction scrap material (brick, wood, steel, metal scraps, and pipe cuttings) shall be stored in a separate covered storage facility adjacent to the shipping container.

Description:

Good Housekeeping BMPs

26

A designated temporary, above-grade concrete washout area shall be constructed. The temporary concrete washout area shall be constructed with a recommended minimum length and minimum width of 10 feet, but with sufficient quantity and volume to contain all liquid and concrete waste generated by washout operations. The washout area shall be lined with plastic sheeting at least 10 mils thick and free of any holes or tears. Signs shall be posted marking the location of the washout area to ensure that concrete equipment operators use the proper facility.

5.3.1 Concrete Washout

DESIGNATE WASHOUT AREAS

Very large items, such as framing materials and stockpiled lumber, shall be stored in the open in the materials storage area. Such materials shall be elevated on wood blocks to minimize contact with runoff. Installation The materials storage area shall be installed after grading and before any Schedule: infrastructure is constructed at the site. Maintenance The storage area shall be inspected weekly and after storm events. The and storage area shall be kept clean, well organized, and equipped with ample Inspection: cleanup supplies as appropriate for the materials being stored. Perimeter controls, containment structures, covers, and liners shall be repaired or replaced as needed to maintain proper function.

Description:

ESTABLISH PROPER MATERIAL STAGING AREAS

T F A R D Installation Schedule:

Description:

Good Housekeeping BMPs

27

A designated temporary, above-grade washout area shall be constructed as needed for the washout and cleanout of stucco, paint, or other non-hazardous construction materials. The temporary washout area shall be a leak-proof container with sufficient volume to contain all liquid and waste generated by washout operations. The temporary washout shall be sited outside of all buffer zones. The washout area shall be constructed as needed.

5.3.2 Applicators, Containers and Paint Washout

Design Specifications: 1. Temporary concrete washout type Above Grade shall be constructed as shown above, with a recommended minimum length and minimum width of 10 feet. 2. The washout shall be a minimum of 50 feet from storm drain inlets. 3. Plastic lining shall be free of holes, tears, or other defects that compromise the impermeability of the material.

Installation Schedule: Maintenance and Inspection:

Concrete pours shall not be conducted during or before an anticipated storm event. Concrete mixer trucks and chutes shall be washed in the designated area or concrete wastes shall be properly disposed of off-site. When the temporary washout area is no longer needed for the construction project, the hardened concrete and materials used to construct the area shall be removed and disposed of according to the maintenance section below, and the area shall be stabilized. The washout area shall be constructed before concrete pours occur at the site. The washout areas shall be inspected daily to ensure that all concrete washing is being discharged into the washout area, no leaks or tears are present, and to identify when concrete wastes need to be removed. The washout areas shall be cleaned out once the area is filled to 75 percent of the holding capacity. Once the area’s holding capacity has been reached, the concrete wastes shall be allowed to harden; the concrete shall be broken up, removed, and taken to an approved landfill for disposal or recycled on-site or offsite in accordance with applicable laws. The plastic sheeting shall be replaced if tears occur during removal of concrete wastes from the washout area.

5.5

5.4

Description:

DISCHARGES

AND

CONTROL

Good Housekeeping BMPs

28

All equipment and vehicle washing shall be performed off-site, except as required for wheel washes and concrete washout areas.

ALLOWABLE NON-STORMWATER EQUIPMENT / VEHICLE WASHING

Several types of vehicles and equipment will likely be used on-site throughout the project, including graders, scrapers, excavators, loaders, paving equipment, rollers, trucks and trailers, backhoes, and forklifts. All major equipment/vehicle fueling and maintenance shall be performed outside of wetland buffer zones. When vehicle fueling must occur on-site, the fueling activity shall occur in the staging area. Only minor equipment maintenance shall occur on-site. All equipment fluids generated from maintenance activities shall be disposed of into designated drums stored on spill pallets in accordance with the Material Handling and Waste Management Section. Absorbent, spill-cleanup materials and spill kits shall be available at the combined staging and materials storage area. Drip pans shall be placed under all equipment receiving maintenance and vehicles and equipment parked overnight. Installation BMPs implemented for equipment and vehicle maintenance and fueling Schedule: activities shall begin at the start of the project. Maintenance Inspect equipment/vehicle storage areas weekly and after storm events. and Vehicles and equipment shall be inspected on each day of use. Leaks shall Inspection: be repaired immediately, using dry cleanup measures where possible and eliminating the source of the discharge. Problem vehicle(s) or equipment shall be removed from the project site. Keep ample supply of spill-cleanup materials on-site and immediately clean up spills and dispose of materials properly. Do not clean surfaces by hosing-down the area

Description:

T F A R D

The washout areas shall be inspected daily to ensure that all washing is being discharged into the washout area, no leaks or tears are present, and to identify when wastes need to be removed. The washout areas shall be cleaned out once the area is filled to 75 percent of the holding capacity. Liquid wastes shall be disposed of in accordance with applicable Federal and State requirements and shall not be discharged into drainage systems.

ESTABLISH PROPER EQUIPMENT/VEHICLE FUELING AND MAINTENANCE PRACTICES

Maintenance and Inspection:

5.7

5.6

T F A R D Description:

Good Housekeeping BMPs

29

Discharges from fertilizers containing nitrogen and phosphorus shall be minimized. Fertilizers shall be applied at rates and amounts consistent with the manufacture’s specification, and shall at no time exceed local, state, or federal specifications. See project landscape specifications for acceptable fertilizers that can be used for the project.

FERTILIZER DISCHARGE RESTRICTIONS

i.

Employee Training: All employees shall be trained as detailed in the Inspection and Maintenance section of this report. ii. Vehicle Maintenance: Vehicles and equipment shall be maintained off-site. All vehicles and equipment including subcontractor vehicles shall be checked for leaking oil and fluids. Vehicles leaking fluids shall not be allowed on-site. iii. Hazardous Material Storage: Hazardous materials shall be stored in accordance with this report and federal and municipal regulations. iv. Spill Kits: Spill kits shall be kept within the materials storage area. Spills: All spills shall be cleaned up immediately upon discovery. Spent absorbent materials and rags shall be hauled off-site immediately after the spill is cleaned up for disposal at an approved landfill. Spills large enough to discharge to surface water shall be reported to the National Response Center at 1-800-424-8802 and MA DEP at 617-792-7653. v. Material safety data sheets: A material inventory and emergency contact information shall be maintained at the on-site project trailer. Installation The spill prevention and control procedures shall be implemented once Schedule: construction begins on-site. Maintenance All personnel shall be instructed the correct procedures for spill prevention and and control. Notices that state these practices shall be posted in the office Inspection: trailer, and the individual who manages day-to-day site operations shall be responsible for seeing that these procedures are followed.

Description:

SPILL PREVENTION AND CONTROL PROCEDURES

Installation N/A Schedule: Maintenance N/A and Inspection:

x x x x x x x x x

Water Used to Control Dust Uncontaminated Excavation Dewatering Landscape Irrigation Fire Hydrant Flushing Firefighting Potable Water including uncontaminated waterline flushing Non-Detergent Laden Vehicle Wash Water Foundation or Footing Drains Uncontaminated air conditioning or compressor condensate

The following is a list of allowable non-stormwater discharges:

T F A R D

Good Housekeeping BMPs

30

Any changes in construction activities that produce other allowable non-stormwater discharges shall be identified, and the SWPPP shall be amended and the appropriate erosion and sediment control shall be implemented.

ALLOWABLE NON-STORMWATER DISCHARGE MANAGEMENT

Except for water used to control dust and irrigation water, the above discharges shall not be routed to areas of exposed soil.

5.8

Fertilizers shall be applied at an appropriate time of year, timed to coincide as closely as possible to the period of maximum vegetation uptake and growth. Avoid applying fertilizers before heavy rains. Do not apply fertilizers to frozen ground or stormwater conveyance channels flowing with water. Maintenance N/A and Inspection:

Installation Schedule:

6.2

T F A R D

The basins shall be inspected weekly and after storm events greater than 0.5 inches during construction. The area shall be checked for signs of erosion, seepage, and structural damage. Erosion, seepage, and structural damage shall be repaired immediately. The temporary sediment riser shall be checked for any damage or obstructions and any damage found shall be repaired and obstructions removed. Immediately after the completion of construction, the plant material shall be watered for 14 consecutive days unless there is sufficient natural rainfall. The area shall be monitored until final stabilization is reached. Following completion of site construction and final stabilization, maintenance and inspection responsibilities shall be taken over by the Owner in accordance with the Long-Term Pollution Prevention Plan and Long-Term Operation & Maintenance Plan.

Infiltration basins shall be excavated during earthwork construction.

Design Specifications: Installation Schedule: Maintenance and Inspection:

Description:

Final Stabilization

31

See Section 5 for maintenance and inspection procedures for the grass drainage channel. Following completion of site construction and final stabilization, maintenance and inspection responsibilities shall be taken over by the Owner in accordance with the Long-Term Pollution Prevention Plan and Long-Term Operation & Maintenance Plan.

Grass drainage channels shall be installed before site grading begins.

Some of the grass drainage channels shall remain as a permanent stormwater management structures for the site. The channels shall convey runoff to stormwater inlets throughout the site. Install according to sitework specifications and details.

GRASS DRAINAGE CHANNELS

Design Specifications: Installation Schedule: Maintenance and Inspection:

Infiltration basins shall be protected from stormwater runoff from the disturbed site during construction. Riprap spillways shall be constructed as detailed on the site plan. Install according to sitework specifications and details.

INFILTRATION BASIN

6.1 Description:

POST-CONSTRUCTION BMPS

6.0

FINAL STABILIZATION

T F A R D

Preparing the soil for vegetative or non-vegetative stabilization; applying mulch or other non-vegetative product to the exposed area; seeding or planting the exposed area; starting any of the activities in listed above on a portion of the area to be stabilized, but not on the entire area; and finalizing arrangements to have stabilization product fully installed in compliance with the applicable deadline for completing stabilization.

For vegetative stabilization, all activities necessary to initially seed or plant the area to be stabilized; and/or For non-vegetative stabilization, the installation or application of all such non-vegetative measures.

7.1

Description:

Final Stabilization

32

Permanent seeding shall be applied immediately after the final design grades are achieved on portions of the site but no later than 7 days after construction activities have permanently ceased. After the entire site is stabilized, any sediment that has accumulated shall be removed and hauled off-site for disposal at an approved landfill. Construction debris, trash and temporary BMPs (including silt fences, material storage areas, sanitary toilets, and inlet protection) shall also be removed and any areas disturbed during removal shall be seeded immediately. Seeding shall be performed in accordance to the Site Plans and Landscape Specifications for the project.

PERMANENT SEEDING

The following sections detail the management practices proposed to achieve final stabilization of the site.

x

x

As soon as practicable, but no later than 7 calendar days after the initiation of soil stabilization measures the following activities are required to be completed:

x

x x x x

In the context of this provision, “immediately” means as soon as practicable, but no later than the end of the next work day, following the day when the earth-disturbing activities have temporarily or permanently ceased. The following activities constitute the initiation of stabilization:

In compliance with the Construction General Permit, soil stabilization measures must be implemented immediately whenever earth-disturbing activities are temporarily or permanently ceased on any portion of the site. Earth-disturbing activities are temporarily ceased when clearing, grading, and excavation within any area of a site that will not include a permanent structure will not resume for a period of 7 or more calendar days, but such activities will resume in the future.

7.0

Maintenance and Inspection:

Installation Schedule:

T F A R D

Final Stabilization

33

Seeding shall occur at portions of the site where construction activities have permanently ceased shall be stabilized, as soon as possible but no later than 14 days after construction ceases. All seeded areas shall be inspected weekly during construction activities for failure and after storm events until a dense cover of vegetation has been established. If failure is noticed at the seeded area, the area shall be reseeded, fertilized, and mulched immediately. After construction is completed at the site, permanently stabilized areas shall be monitored until final stabilization is reached.

INSPECTIONS

8.1

Inspections and Maintenance

For detailed inspection procedures, see Sections 4 and 5.

34

Utility line installation, pipeline construction, and other examples of long, narrow, linear construction activities may limit the access of inspection personnel to the areas described in the above paragraph. Inspection of these areas could require that vehicles compromise temporarily or even permanently stabilized areas, cause additional disturbance of soils, and increase the potential for erosion. In these circumstances, controls shall be inspected on the same frequencies as other construction projects, but representative inspections may be performed. For representative inspections, personnel shall inspect controls along the construction site for 0.25 mile above and below each access point where a roadway, undisturbed right-of-way, or other similar feature intersects the construction site and allows access to the areas described above. The conditions of the controls along each inspected 0.25 mile segment may be considered as representative of the condition of controls along that reach extending from the end of the 0.25 mile segment to either the end of the next 0.25 mile inspected segment, or to the end of the project, whichever occurs first.

T F A R D

Inspections shall include all areas of the site disturbed by construction activity and areas used for storage of materials that are exposed to precipitation. Inspectors shall look for evidence of, or the potential for, pollutants entering the storm water conveyance system. Sedimentation and erosion control measures identified in the SWPPP shall be observed to ensure proper operation. Discharge locations shall be inspected to ascertain whether erosion control measures are effective in preventing significant impacts to waters of the United States, where accessible. Where discharge locations are inaccessible, nearby downstream locations shall be inspected to the extent that such inspections are practicable. Locations where vehicles enter or exit the site shall be inspected for evidence of off-site sediment tracking.

Inspections of the site will be performed once every 7 days and within 24 hours of the end of a storm event of 0.25-inch or greater unless otherwise specified. The inspections will verify that all BMPs required are implemented, maintained, and effectively minimizing erosion and preventing stormwater contamination from construction materials.

8.1.1 Inspection Schedule and Procedures

INSPECTIONS AND MAINTENANCE

8.0

8.3

8.2

T F A R D

See Appendix F – Corrective Action Log.

Inspections and Maintenance

35

If it is determined the stormwater controls have not been installed as required, or that they are not functioning adequately corrective action is required within 7 calendar days.

The corrective action log describes repairs, replacements, and maintenance of BMPs undertaken as a result of the inspections and maintenance procedures. Additionally, remedies of permit violations and clean and proper disposal of spills, releases other deposits should be recorded.

CORRECTIVE ACTION LOG

If earth-disturbing activities are suspended due to frozen conditions inspections can be temporarily suspended until a thaw occurs.

Once an area is stabilized, inspections may be reduced to once per month. If construction resumes at the stabilized area the inspection frequency shall increase as outlined in section 8.1.

REDUCTIONS IN INSPECTION FREQUENCY

For a copy of the inspection report template, see Appendix E.

Inspection reports are required to be completed within 24-hours of an inspection. If corrective actions are identified by the Inspector during the inspection, he/she shall notify and submit a copy of the inspection report to the Operator(s). For corrective actions identified, the project managers shall be responsible for initiating the corrective action within 24 hours of the report and completing maintenance as soon as possible or before the next storm event. For any corrective actions requiring a SWPPP amendment or change to a stormwater conveyance or control design, the project manager shall notify the Owner, as soon as possible, before initiating the corrective action.

All inspections shall be coordinated with a representative from Clean Energy Collective. A Clean Energy Collective representative shall accompany Name of inspector, when possible, during inspections.

9.3

9.2

RECORDKEEPING

9.1

Company/Organization: TBD Name: TBD

9.3.1 Individual(s) Responsible for Training

Record Keeping and Training

36

Prior to the commencement of earth-disturbing activities or pollutant-generating activities, whichever occurs first, training on the pollution prevention measures outlined in this SWPPP shall be provided to staff and subcontractors.

TRAINING

The log of changes to the SWPPP is maintained in Appendix G and includes additions of new BMPs, replacement of failed BMPs, significant changes in the activities or their timing on the project, changes in personnel, changes in inspection and maintenance procedures and update to site plans.

LOG OF CHANGES TO THE SWPPP

Date(s) when an area is either temporarily or permanently stabilized: See Appendix I – Grading and Stabilization Activities Log

Date(s) when construction activities temporarily or permanently cease on a portion of the site: See Appendix I – Grading and Stabilization Activities Log

T F A R D

Date(s) when major grading activities occur: See Appendix I – Grading and Stabilization Activities Log

The following records shall be kept at the project site and shall be available for inspectors to review. These records shall be retained for a minimum period of at least 3 years after the permit is terminated.

A copy of the SWPPP, along with all inspection reports and corrective action logs are required to be stored at an accessible location at the site, and shall be made available upon request of the EPA, or state or local agency approving stormwater management plans.

RECORDKEEPING AND TRAINING

9.0

Record Keeping and Training

T F A R D

37

Formal training shall be provided to all staff and subcontractors with specific stormwater responsibilities, such as installing and maintaining BMPs. The formal training shall cover all design and construction specifications for installing the BMPs and proper procedures for maintaining each BMP. Formal training shall occur before any BMPs are installed on the site. (See Appendix J – Training Log)

Informal training shall be conducted for all staff, including subcontractors, on the site. The training shall be conducted primarily via tailgate sessions and shall focus on avoiding damage to stormwater BMPs and preventing illicit discharges. The tailgate sessions shall be conducted biweekly and shall address the following topics: Erosion Control BMPs, Sediment Control BMPs, Non-Stormwater BMPs, Waste Management and Materials Storage BMPs, and Emergency Procedures specific to the construction site. (See Appendix J – Training Log)

9.3.2 Description of Training Conducted

SIGNATURE, PLAN REVIEW, AND MAKING PLANS AVAILABLE

10.1

T F A R D

NOTICE OF PERMIT COVERAGE

x

x x x

Certification and Notification

38

The NPDES Permit Tracking Number, A contact name and phone number for obtaining additional construction site information, The Uniform Resource Locator (URL) for the SWPPP (if available), or the following statement: “If you would like to obtain a copy of the Stormwater Pollution Prevention Plan (SWPPP) for this site, contact the EPA Regional 1 Office at (617) 918-1038, The following statement “If you observe indicators of stormwater pollutants in the discharge or in the receiving waterbody, contact the EPA through the following website: https://www.epa.gov/enforcement/report-environmental-violations.”

A sign must be posted at a safe, publicly accessible location in close proximity to the construction site detailing the permit coverage. The notice must be located so that it is visible from the public road that is nearest to the active part of the construction site, and it must use a font large enough to be readily viewed from a public right-of-way. At a minimum, the notice must include:

10.2

A copy of the SWPPP (including a copy of the Construction General Permit, NOI, and acknowledgement letter from EPA shall be retained at the construction site (or other location easily accessible during normal business hours to EPA, a state, tribal or local agency approving sediment and erosion plans, grading plans, or storm water management plans; local government officials; the operator of a municipal separate storm sewer receiving discharges from the site; and representatives of the U.S. Fish and Wildlife Service or the National Marine Fisheries Service) from the date of commencement of construction activities to the date of final stabilization. A copy of the SWPPP shall be available at a central location on-site for the use of all those identified as having responsibilities under the SWPPP. If an on-site location is unavailable to store the SWPPP when no personnel are present, notice of the plan’s location shall be posted near the main entrance at the construction site.

CERTIFICATION AND NOTIFICATION

10.0

000000RP000

Project Name Stormwater Pollution Prevention Plan (SWPPP) Town, Massachusetts

10.3

Certification and Notification

T F A R D

Signature:________________________________ Date:_______________________

Name:___________________________________ Title:_______________________

39

I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gathered and evaluated the information submitted. Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering the information, the information submitted is, to the best of my knowledge and belief, true, accurate, and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations.

OWNER CERTIFICATION

10.4

Certification and Notification

T F A R D

Signature:________________________________ Date:_______________________

Name:___________________________________ Title:_______________________

40

I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gathered and evaluated the information submitted. Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering the information, the information submitted is, to the best of my knowledge and belief, true, accurate, and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations.

OPERATOR CERTIFICATION

T F A R D

APPENDICES

T F A R D General Location Map

Appendix A

T F A R D

Site Plans

Appendix B

Appendix C

https://www.epa.gov/sites/production/files/2017-02/documents/2017_cgp_final_permit_508.pdf

Construction General Permit

T F A R D

Appendix D NOI and Acknowledgement Letter from EPA

T F A R D

Inspection Reports

Appendix E

The following four pages should be copied and completed for each inspection. All inspection forms should be compiled in a binder to prove compliance with this SWPPP.

Inspections under this SWPPP shall be conducted in accordance with each installed BMPs recommended maintenance requirements. This inspection frequency may be reduced to at least once every month if: a) the entire site is temporarily stabilized, b) runoff is unlikely due to winter conditions (e.g. site is covered with snow, ice, or the ground is frozen), or c) construction is occurring during seasonal arid periods in arid areas and semi-arid areas. If an inspection report is filed according to this modified schedule it shall be noted at the end of the report under the “NOTES” section.

T F A R D

Are there any discharges at the time of inspection? ‰Yes If yes, describe:

‰No

‰ High Winds ‰No

‰ Fog ‰ Snowing Temperature: Have any discharges occurred since the last inspection? ‰Yes If yes, describe:

Weather at time of this inspection? ‰ Clear ‰Cloudy ‰ Rain ‰ Sleet ‰ Other:

Approx. Amount of Precipitation (in):

‰ During storm event ‰ Post-storm event Weather Information Has there been a storm event since the last inspection? ‰Yes ‰No If yes, provide: Storm Start Date & Time: Storm Duration (hrs):

Inspector’s Contact Information Inspector’s Qualifications Describe present phase of construction Type of Inspection: ‰ Regular ‰ Pre-storm event

Inspector’s Title(s)

T F A R D

Start/End Time

Date of Inspection Inspector’s Name(s)

Location

General Information

NPDES Tracking No.

Project Name

Stormwater Pollution Prevention Plan: Inspection Checklist

E-1

BMP

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

Corrective Action Needed and Notes

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

T F A R D

BMP Maintenance Required?

BMP Installed?

E-2

Site-specific BMPs x Number the structural and non-structural BMPs identified in your SWPPP on your site map and list them below (add as many BMPs as necessary). Carry a copy of the numbered site map with you during your inspections. This list will ensure that you are inspecting all required BMPs at your site. x Describe corrective actions initiated, date completed, and note the person that completed the work in the Corrective Action Log.

Are vehicle and equipment fueling, cleaning, and maintenance areas free of spills, leaks, or any other deleterious material?

Are washout facilities (e.g., paint, stucco, concrete) available, clearly marked, and maintained?

Is trash/litter from work areas collected and placed in covered dumpsters?

Is the construction exit preventing sediment from being tracked into the street?

Are storm drain inlets properly protected?

Are discharge points and receiving waters free of any sediment deposits?

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

Maintenance Required?

E-3

Corrective Action Needed and Notes

T F A R D

‰Yes ‰No

Are natural resource areas (e.g., streams, wetlands, mature trees, etc.) protected with barriers or similar BMPs?

‰Yes ‰No

‰Yes ‰No

Are all slopes and disturbed areas not actively being worked properly stabilized?

Are perimeter controls and sediment barriers adequately installed (keyed into substrate) and maintained?

Implemented?

BMP/activity

Overall Site Issues Below are some general site issues that should be assessed during inspections. Customize this list as needed for conditions at your site.

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

Are non-stormwater discharges (e.g., wash water, dewatering) properly controlled?

(Other)

Corrective Action Needed and Notes

Date:_____________________

Signature:_________________________________________________________

___________________________________________________________________________

Print name and title:

E-4

“I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gathered and evaluated the information submitted. Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering the information, the information submitted is, to the best of my knowledge and belief, true, accurate, and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations.”

CERTIFICATION STATEMENT

Describe any incidents of non-compliance not described above:

Non-Compliance

T F A R D

‰Yes ‰No

‰Yes ‰No

Are materials that are potential stormwater contaminants stored inside or under cover?

Maintenance Required?

Implemented?

BMP/activity

T F A R D

Corrective Action Log

Appendix F

Date

Additional Action Items

T F A R D

Activity Description

F-1

Use this form to note the date and activity for accurate record keeping (make additional copies as necessary). Examples include the restaking or reinforcement of the erosion control barrier, site watering to prevent dust erosion, street sweeping, equipment and machinery repair, etc.

Corrective Action Log

Appendix G

Based on the results of an inspection, the SWPPP shall be modified as necessary to include additional or modified BMPs designed to correct problems identified. Revisions to the SWPPP shall be completed within seven (7) calendar days following the inspection. Implementation of these additional or modified BMPs shall be accomplished as described in Subpart 3.6B of the Construction General Permit (located in Appendix C).

The SWPPP shall be amended if during inspections or investigations by site staff, or by local, state, tribal or federal officials, it is determined that the SWPPP is ineffective in eliminating or significantly minimizing pollutants in storm water discharges from the construction site.

The SWPPP, including the site plans, shall be amended whenever there is a change in design, construction, operation, or maintenance at the construction site that has or could have a significant effect on the discharge of pollutants to the waters of the United States that has not been previously addressed in the SWPPP.

SWPPP Amendment Log

T F A R D

Amendment No.

Date of Amendment

T F A R D

Description of the Amendment

SWPPP Amendment Log

G-1

Amendment Prepared by (Name(s) and Title)

Appendix H Subcontractor Certifications/Agreements

T F A R D

T F A R D

Date:

Title:

Signature:

Type of construction service to be provided:

Telephone Number:

Address:

Company:

This certification is hereby signed in reference to the above named project:

I certify under the penalty of law that I have read and understand the terms and conditions of the SWPPP for the above designated project and agree to follow the practices described in the SWPPP.

Each subcontractor engaged in activities at the construction site that could impact stormwater must be identified and sign the following certification statement:

As a subcontractor, you are required to comply with the Stormwater Pollution Prevention Plan (SWPPP) for any work that you perform on-site. Any person or group who violates any condition of the SWPPP may be subject to substantial penalties or loss of contract. You are encouraged to advise each of your employees working on this project of the requirements of the SWPPP. A copy of the SWPPP is available for your review at the office trailer.

Operator(s):

Project Title:

Project Number:

SUBCONTRACTOR CERTIFICATION STORMWATER POLLUTION PREVENTION PLAN

Sample Subcontractor Certifications/Agreements

Appendix I

Site Plans in Appendix B should be annotated to indicate areas where final stabilization has been accomplished and no further construction-phase permit requirements apply.

Grading and Stabilization Activities Log

T F A R D

Date

Description

T F A R D

Location on Property

Grading and Stabilization Activities Log

I-1

The following records are to be kept by each Site Operator throughout the construction period and maintained in the SWPPP. Insert additional documentation for record keeping as necessary.

T F A R D

Training Log

Appendix J

Date

Training Log Attendee

T F A R D

Training Topic

Signature of Training Coordinator

J-1

T F A R D

Delegation of Authority

Appendix K

Date:

Signature:

Title:

Company:

Name:

I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gathered and evaluated the information submitted. Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering the information, the information submitted is, to the best of my knowledge and belief, true, accurate, and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations.

By signing this authorization, I confirm that I meet the requirements to make such a designation as set forth in Appendix I of EPA’s Construction General Permit (CGP), and that the designee above meets the definition of a “duly authorized representative” as set forth in Appendix I.

T F A R D

________________________________________ (name of person or position) ________________________________________ (company) ________________________________________ (address) ________________________________________ (city, state, zip) ________________________________________ (phone)

I, _______________________ (name), hereby designate the person or specifically described position below to be a duly authorized representative for the purpose of overseeing compliance with environmental requirements, including the Construction General Permit, at the ____________________________________ construction site. The designee is authorized to sign any reports, stormwater pollution prevention plans and all other documents required by the permit.

Delegation of Authority

Sample Delegation of Authority Form

Appendix L Endangered Species Documentation

T F A R D

Appendix M

Historic Preservation Documentation

T F A R D

Appendix N Temporary Sediment Basin Sizing Calculations

T F A R D

Appendix O

Natural Buffer Equivalency Calculations

T F A R D

Section 5.0 Plans Locus Map Aerial Map Entitled “CEC #1206, LLC in Hopkinton, Massachusetts (Middlesex County)” Prepared by Beals and Thomas, Inc. In 19 Sheets Dated August 10, 2017

Site

HOPKINTON MILFOR D

Digital USGS Map of Milford, MA, dated 1982, provided by the Office of Geographic and Environmental Information (MassGIS), Commonwealth of Massachusetts Executive Office of Energy and Environmental Affairs.

Z 0 FEET

1,000

2,000

4,000

PROJECT:

Figure 1

Hopkinton, Massachusetts

CEC Solar #1206, LLC c/o Clean Energy Collective 146 West Boylston Drive, 3rd Floor Worcester, MA 01606

BEALS+ THOMAS

NORTH

COP YRIGHT (C) BY BEALS AND TH OMAS , INC. ALL RIGHTS RES ERVE D

Locus Map

CEC Solar #1206, LLC

PREPARED FOR:

North Arrow

Scale: 1" = 2,000'

Date: 03/29/2017

Source File 283600P007A.mxd B+T Project No. 2836.00

North Arrow

Z

Digital Globe, MassGIS Digital orthophotograph, dated 2015, provided by the Office of Geographic and Environmental Information (MassGIS), Commonwealth of Massachusetts Executive Office of Energy and Environmental Affairs.

0 FEET

155

310

620

PROJECT:

Aerial Map

CEC Solar #1206, LLC

Figure 2

Hopktinton, Massachusetts

PREPARED FOR:

CEC Solar #1206, LLC c/o Clean Energy Collective 146 West Boylston Drive, 3rd Floor Worcester, Massachusetts

BEALS+ THOMAS

NORTH

COP YRIGHT (C) BY BEALS AND TH OMAS , INC. ALL RIGHTS RES ERVE D

Scale: 1" = 300'

Date: 03/29/2017

Source File 283600P008A.mxd B+T Project No. 2836.00

CEC Solar #1206, LLC Stormwater Management Report Hopkinton, Massachusetts 283600RP001A

TABLE OF CONTENTS 1.0

INTRODUCTION .............................................................................................................................................. 1

2.0

PRE-DEVELOPMENT CONDITIONS........................................................................................................... 2

2.1 2.2 2.3 3.0

SITE CONDITIONS ............................................................................................................................................ 2 SOIL DESCRIPTION .......................................................................................................................................... 2 HYDROLOGIC ANALYSIS .................................................................................................................................. 3

POST-DEVELOPMENT CONDITIONS ........................................................................................................ 3

3.1 3.2 3.3 3.4 3.5 3.6

DESIGN STRATEGY ........................................................................................................................................... 3 HYDROLOGIC ANALYSIS .................................................................................................................................. 3 STORMWATER MANAGEMENT CONTROLS SIZING ............................................................................................ 3 COMPLIANCE WITH DEP STORMWATER MANAGEMENT STANDARDS .............................................................. 3 ILLICIT DISCHARGE COMPLIANCE STATEMENT ................................................................................................ 6 DEP’S CHECKLIST FOR A STORMWATER REPORT ............................................................................................ 7

LIST OF APPENDICES APPENDIX A: SOIL DATA APPENDIX B: PRE-DEVELOPMENT HYDROLOGIC ANALYSIS APPENDIX C: POST-DEVELOPMENT HYDROLOGIC ANALYSIS APPENDIX D: DRAWDOWN & RIPRAP-SIZING CALCULATIONS APPENDIX E: SITE OWNER’S MANUAL APPENDIX F: STORMWATER POLLUTION PREVENTION PLAN

Table of Contents

i

CEC Solar #1206, LLC Stormwater Management Report Hopkinton, Massachusetts 283600RP001

1.0

INTRODUCTION

The proposed project includes a stormwater management system designed to mitigate potential impacts the proposed project could have on the existing watershed. Stormwater controls have been proposed to control peak runoff rates, provide water quality, promote groundwater recharge, and sediment removal. The proposed system has been designed to comply with: •

The 2008 Massachusetts Department of Environmental Protection (DEP) Stormwater Management Handbook,

• •

The Massachusetts Wetland Protection Act (310 CMR 10.00), and Town of Hopkinton Wetlands Protection Regulations

The pre- and post-development hydrologic conditions were modeled using HydroCADTM version 10.00 to demonstrate that post-development stormwater runoff rates will be less than or equal to the pre-development rates. Watershed maps with soil types as well as detailed analysis of the model results are also included. The following table summarizes the peak runoff rates and volumes for the pre- and post-development conditions. Table 1: Pre- & Post-development Peak Runoff Rate Comparison, units are in cubic feet per second (cfs).

Storm Event Design Point 1 Design Point 2 Design Point 3

2 Year Pre Post 0.00 0.00 0.22 0.19 0.22 0.14

10 Year Pre Post 0.04 0.00 1.95 1.81 2.35 1.85

25 Year Pre Post 0.27 0.26 4.21 4.10 5.29 5.19

100 Year Pre Post 3.08 2.24 10.21 10.19 13.23 12.24

1

CEC Solar #1206, LLC Stormwater Management Report Hopkinton, Massachusetts 283600RP001

2.0

PRE-DEVELOPMENT CONDITIONS

2.1

Site Conditions The proposed ground-mounted solar facility is located on an approximately 11.4-acre site (the Site) which is partially developed and occupied by a single-family residence. The solar array is proposed within an area that is comprised of predominantly woodland vegetation. The array is accessed off of the existing driveway associated with the dwelling on Lumber Street. The array is approximately centered on a high-point. Runoff from the Site drains to the east and to the west. There are on-site bordering vegetated wetlands (BVW) at the eastern perimeter of the Site as well as a potential vernal pool (PVP) and associated isolated vegetated wetland (IVW) at the southeastern quadrant. There is also a BVW at the western perimeter of the Site (adjacent to Lumber Street). The resource areas at northeastern and western portions of the Site ultimately flow to the north. The southeastern potion of the Site (including the PVP and IVW) flow to the east and south. These three locations described serve as the design points evaluated in the hydrologic analysis. A portion of the Site is within an Outstanding Resource Water (ORW). As described below, the project is proposed in accordance with Massachusetts DEP Stormwater Management Policy.

2.2

Soil Description The Natural Resources Conservation Service (NRCS) Web Soil Survey lists the on-site soils as Canton Fine Sandy Loam, Narragansett Silt Loam, and some areas of Ridgebury Fine Sandy Loam. Canton Fine Sandy Loam is a very deep, well-drained soil on glaciated uplands. The typical soil profile is comprised of layers of fine sandy loam over gravelly fine sandy loam, over gravelly loamy sand. NRCS classifies these soils as Hydrologic Soil Group (HSG) “A” (extremely bouldery) & “B” (extremely stony). Narragansett Silt Loam is a deep, well drained soil on glacial till plains and ground moraine. The typical soil profile is comprised of layers of silt loam over very gravelly loamy sand. NRCS classifies this soil as HSG “A”. Ridgebury Fine Sandy Loam is a very deep, poorly drained to somewhat poorly drained soil on glacial till uplands. The typical soil profile is comprised of layers of fine sandy loam over loamy fine sand, sand, and gravelly coarse sand. NRCS classifies this soil as HSG “D”.

2

CEC Solar #1206, LLC Stormwater Management Report Hopkinton, Massachusetts 283600RP001

2.3

Hydrologic Analysis Sub-catchment areas were delineated based on existing runoff patterns and topographic information. This information is shown on the Pre-Development Conditions Hydrologic Areas Map included in Appendix B. Summaries of each area with respect to Curve Number and Time of Concentration calculations can be found in the model results also in Appendix B.

3.0

POST-DEVELOPMENT CONDITIONS

3.1

Design Strategy The proposed solar array will include stormwater management measures to control peak rates of runoff from the Site. During the design phase of the site layout, consideration was given to minimizing the impact on the existing Site hydrology. To achieve this, grading was minimized to the maximum extent practicable and the Site was designed to match existing terrain where feasible, in order to maintain drainage patterns to maximum extent practicable. Stormwater runoff is directed to the proposed Best Management Practices (BMPs) via overland flow, with diversion berms and conveyance swales, if needed.

3.2

Hydrologic Analysis The established design points used in the pre-development conditions analysis were used in the post-development analysis for direct comparison. The tributary areas and flow paths were modified to reflect post-development conditions. See Appendix C for the Post- Development Conditions Hydrologic Areas Map. Summaries of each area with respect to Curve Number and Time of Concentration calculations can be found in the model results in Appendix C.

3.3

Stormwater Management Controls Sizing Infiltration Basin The three proposed stormwater infiltration basins have been designed to reduce peak runoff rates. All three basins have one to three pipe outlets and a riprap emergency spillway. The basins have been modeled with a conservative infiltration rate of 0.27 inches per hour consistent with HSG “C” soils, though the basins are proposed in areas mapped as HSG “A” & “B”. The basins dewater within 72 hours, as demonstrated by the drawdown calculations in Appendix D.

3.4

Compliance with DEP Stormwater Management Standards The proposed stormwater management system was designed in compliance with the ten (10) DEP Stormwater Management Standards. The following summary provides key information related to the proposed stormwater management system, its design elements, and mitigation measures for potential impacts.

3

CEC Solar #1206, LLC Stormwater Management Report Hopkinton, Massachusetts 283600RP001

STANDARD 1:

No new stormwater conveyance (e.g. outfalls) may discharge untreated stormwater directly to or cause erosion in wetlands or waters of the Commonwealth.

Existing drainage patterns will be maintained. There are no contiguous impervious ground surfaces proposed, with the exception of relatively minor equipment pads. Three infiltration basins have been designed to mitigate stormwater runoff rates associated with the proposed project. Outlets from the basins have been designed to minimize the potential for erosion.

STANDARD 2:

Stormwater management systems shall be designed so that postdevelopment peak discharge rates do not exceed pre-development peak discharge rates.

The stormwater management design will control post-development peak discharge rates for the 2-, 10-, 25-, and 100-year, 24-hour storms so as to maintain pre-development peak discharge rates. Refer to Section 1.0 Introduction for a summary of the peak runoff rates.

STANDARD 3:

Loss of annual recharge to groundwater shall be eliminated or minimized through the use of environmentally sensitive site design, low impact development techniques, stormwater management practices and good operation and maintenance. At a minimum, the annual recharge from the post-development site shall approximate the annual recharge from pre-development conditions based on soil types. This Standard is met when the stormwater management system is designed to infiltrate the required recharge volume as determined in accordance with the Massachusetts Stormwater Handbook.

Groundwater recharge will be maintained as no contiguous impervious ground surfaces are proposed as part of this project, with the exception of two relatively small equipment pads. The stormwater management system includes infiltration basins that will promote groundwater recharge onsite. As a result, annual recharge from the post-development site will approximate the annual recharge from the site under pre-development conditions.

STANDARD 4:

Stormwater management systems shall be designed to remove 80% of the average annual post-construction load of Total Suspended Solids (TSS).

4

CEC Solar #1206, LLC Stormwater Management Report Hopkinton, Massachusetts 283600RP001

The project does not include proposed impervious surfaces requiring treatment, therefore the 80% TSS removal requirement does not apply. A Site Owner’s Manual has been developed to comply with the Long-Term Pollution Prevention Plan (Standard 4) and the Long-Term Operation and Maintenance Plan (Standard 9) requirements of the 2008 Massachusetts Department of Environmental Protection (MassDEP) Stormwater Management Standards. The Manual outlines source control and pollution prevention measures and maintenance requirements of stormwater BMPs associated with the proposed project.

STANDARD 5:

For land uses with higher potential pollutant loads (LUHPPLs), source control and pollution prevention shall be implemented in accordance with the Massachusetts Stormwater Handbook to eliminate or reduce the discharge of stormwater runoff from such land uses to the maximum extent practicable.

The proposed project is not associated with stormwater discharges from land uses with higher potential pollutant loads.

STANDARD 6:

Stormwater discharges to critical areas must utilize certain stormwater management BMPs approved for critical areas. Critical areas are Outstanding Resource Waters, shellfish beds, swimming beaches, coldwater fisheries and recharge areas for public water supplies.

The proposed BMPs are consistent with the Stormwater Management Handbook for use within the ORW critical area. Impervious areas requiring treatment are not proposed as part of this project.

STANDARD 7:

Redevelopment of previously developed sites must meet the Stormwater Management Standards to the maximum extent practicable. However, if it is not practicable to meet all the Standards, new (retrofitted or expanded) stormwater management systems must be designed to improve existing conditions.

The proposed project is new development, and therefore this standard does not apply.

5

CEC Solar #1206, LLC Stormwater Management Report Hopkinton, Massachusetts 283600RP001

STANDARD 8:

A plan to control construction-related impacts during erosion, sedimentation and other pollutant sources during construction and land disturbance activities (construction period erosion, sedimentation, and pollution prevention plan) shall be developed and implemented.

A draft Stormwater Pollution Prevention Plan (SWPPP) has been developed to comply with Section 3 of the NPDES Construction General Permit for Stormwater Discharges; therefore the requirements of Standard 8 are fulfilled.

STANDARD 9:

A Long-Term Operation and Maintenance (O&M) Plan shall be developed and implemented to ensure that stormwater management systems function as designed.

The Site Owner’s Manual complies with the Long-Term Pollution Prevention Plan (Standard 4) and the Long-Term Operation and Maintenance Plan (Standard 9) requirements of the 2008 Massachusetts Department of Environmental Protection (MassDEP) Stormwater Management Standards. The Manual outlines source control and pollution prevention measures and maintenance requirements of the stormwater BMPs associated with the proposed development.

STANDARD 10:

All illicit discharges to the stormwater management system are prohibited.

There will be no illicit discharges to the proposed stormwater management system associated with the proposed project. An Illicit Discharge Compliance Statement is provided on the following page.

3.5

Illicit Discharge Compliance Statement

6

CEC Solar #1206, LLC Stormwater Management Report Hopkinton, Massachusetts 283600RP001

An illicit discharge is any discharge to a municipal separate storm sewer that is not comprised entirely of stormwater, discharges from fire-fighting activities, and certain non-designated non-stormwater discharges. To the best of my knowledge, no detectable illicit discharge exists on site. The site plans included with this report detail the storm sewers that convey stormwater on the site and demonstrate that these systems do not include the entry of an illicit discharge. A Site Owner’s Manual is also included, which contains the Long Term Pollution Plan that outlines measures to prevent future illicit discharges. As the Site Owner, I will ultimately be responsible for implementing the Long Term Pollution Prevention Plan.

Signature:

_______________________________________ Owner’s Name

DEP’s Checklist for a Stormwater Report

7

Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program

Checklist for Stormwater Report A. Introduction Important: When filling out forms on the computer, use only the tab key to move your cursor - do not use the return key.

A Stormwater Report must be submitted with the Notice of Intent permit application to document compliance with the Stormwater Management Standards. The following checklist is NOT a substitute for the Stormwater Report (which should provide more substantive and detailed information) but is offered here as a tool to help the applicant organize their Stormwater Management documentation for their Report and for the reviewer to assess this information in a consistent format. As noted in the Checklist, the Stormwater Report must contain the engineering computations and supporting information set forth in Volume 3 of the Massachusetts Stormwater Handbook. The Stormwater Report must be prepared and certified by a Registered Professional Engineer (RPE) licensed in the Commonwealth. The Stormwater Report must include: • The Stormwater Checklist completed and stamped by a Registered Professional Engineer (see page 2) that certifies that the Stormwater Report contains all required submittals.1 This Checklist is to be used as the cover for the completed Stormwater Report. • Applicant/Project Name • Project Address • Name of Firm and Registered Professional Engineer that prepared the Report • Long-Term Pollution Prevention Plan required by Standards 4-6 • Construction Period Pollution Prevention and Erosion and Sedimentation Control Plan required by Standard 82 • Operation and Maintenance Plan required by Standard 9 In addition to all plans and supporting information, the Stormwater Report must include a brief narrative describing stormwater management practices, including environmentally sensitive site design and LID techniques, along with a diagram depicting runoff through the proposed BMP treatment train. Plans are required to show existing and proposed conditions, identify all wetland resource areas, NRCS soil types, critical areas, Land Uses with Higher Potential Pollutant Loads (LUHPPL), and any areas on the site where infiltration rate is greater than 2.4 inches per hour. The Plans shall identify the drainage areas for both existing and proposed conditions at a scale that enables verification of supporting calculations. As noted in the Checklist, the Stormwater Management Report shall document compliance with each of the Stormwater Management Standards as provided in the Massachusetts Stormwater Handbook. The soils evaluation and calculations shall be done using the methodologies set forth in Volume 3 of the Massachusetts Stormwater Handbook. To ensure that the Stormwater Report is complete, applicants are required to fill in the Stormwater Report Checklist by checking the box to indicate that the specified information has been included in the Stormwater Report. If any of the information specified in the checklist has not been submitted, the applicant must provide an explanation. The completed Stormwater Report Checklist and Certification must be submitted with the Stormwater Report.

1

The Stormwater Report may also include the Illicit Discharge Compliance Statement required by Standard 10. If not included in the Stormwater Report, the Illicit Discharge Compliance Statement must be submitted prior to the discharge of stormwater runoff to the post-construction best management practices. 2

For some complex projects, it may not be possible to include the Construction Period Erosion and Sedimentation Control Plan in the Stormwater Report. In that event, the issuing authority has the discretion to issue an Order of Conditions that approves the project and includes a condition requiring the proponent to submit the Construction Period Erosion and Sedimentation Control Plan before commencing any land disturbance activity on the site.

283600swcheck.doc • 04/01/08

Stormwater Report Checklist • Page 1 of 8

Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program

Checklist for Stormwater Report Checklist (continued) LID Measures: Stormwater Standards require LID measures to be considered. Document what environmentally sensitive design and LID Techniques were considered during the planning and design of the project: No disturbance to any Wetland Resource Areas Site Design Practices (e.g. clustered development, reduced frontage setbacks) Reduced Impervious Area (Redevelopment Only) Minimizing disturbance to existing trees and shrubs LID Site Design Credit Requested: Credit 1 Credit 2 Credit 3 Use of “country drainage” versus curb and gutter conveyance and pipe Bioretention Cells (includes Rain Gardens) Constructed Stormwater Wetlands (includes Gravel Wetlands designs) Treebox Filter Water Quality Swale Grass Channel Green Roof Other (describe):

Standard 1: No New Untreated Discharges No new untreated discharges Outlets have been designed so there is no erosion or scour to wetlands and waters of the Commonwealth Supporting calculations specified in Volume 3 of the Massachusetts Stormwater Handbook included.

283600swcheck.doc • 04/01/08

Stormwater Report Checklist • Page 3 of 8

Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program

Checklist for Stormwater Report Checklist (continued) Standard 2: Peak Rate Attenuation Standard 2 waiver requested because the project is located in land subject to coastal storm flowage and stormwater discharge is to a wetland subject to coastal flooding. Evaluation provided to determine whether off-site flooding increases during the 100-year 24-hour storm. Calculations provided to show that post-development peak discharge rates do not exceed predevelopment rates for the 2-year and 10-year 24-hour storms. If evaluation shows that off-site flooding increases during the 100-year 24-hour storm, calculations are also provided to show that post-development peak discharge rates do not exceed pre-development rates for the 100-year 24hour storm. Standard 3: Recharge Soil Analysis provided. Required Recharge Volume calculation provided. Required Recharge volume reduced through use of the LID site Design Credits. Sizing the infiltration, BMPs is based on the following method: Check the method used. Static

Simple Dynamic

Dynamic Field1

Runoff from all impervious areas at the site discharging to the infiltration BMP. Runoff from all impervious areas at the site is not discharging to the infiltration BMP and calculations are provided showing that the drainage area contributing runoff to the infiltration BMPs is sufficient to generate the required recharge volume. Recharge BMPs have been sized to infiltrate the Required Recharge Volume. Recharge BMPs have been sized to infiltrate the Required Recharge Volume only to the maximum extent practicable for the following reason: Site is comprised solely of C and D soils and/or bedrock at the land surface M.G.L. c. 21E sites pursuant to 310 CMR 40.0000 Solid Waste Landfill pursuant to 310 CMR 19.000 Project is otherwise subject to Stormwater Management Standards only to the maximum extent practicable. Calculations showing that the infiltration BMPs will drain in 72 hours are provided. Property includes a M.G.L. c. 21E site or a solid waste landfill and a mounding analysis is included.

1

80% TSS removal is required prior to discharge to infiltration BMP if Dynamic Field method is used.

283600swcheck.doc • 04/01/08

Stormwater Report Checklist • Page 4 of 8

Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program

Checklist for Stormwater Report Checklist (continued) Standard 3: Recharge (continued) The infiltration BMP is used to attenuate peak flows during storms greater than or equal to the 10year 24-hour storm and separation to seasonal high groundwater is less than 4 feet and a mounding analysis is provided. Documentation is provided showing that infiltration BMPs do not adversely impact nearby wetland resource areas. Standard 4: Water Quality The Long-Term Pollution Prevention Plan typically includes the following: • Good housekeeping practices; • Provisions for storing materials and waste products inside or under cover; • Vehicle washing controls; • Requirements for routine inspections and maintenance of stormwater BMPs; • Spill prevention and response plans; • Provisions for maintenance of lawns, gardens, and other landscaped areas; • Requirements for storage and use of fertilizers, herbicides, and pesticides; • Pet waste management provisions; • Provisions for operation and management of septic systems; • Provisions for solid waste management; • Snow disposal and plowing plans relative to Wetland Resource Areas; • Winter Road Salt and/or Sand Use and Storage restrictions; • Street sweeping schedules; • Provisions for prevention of illicit discharges to the stormwater management system; • Documentation that Stormwater BMPs are designed to provide for shutdown and containment in the event of a spill or discharges to or near critical areas or from LUHPPL; • Training for staff or personnel involved with implementing Long-Term Pollution Prevention Plan; • List of Emergency contacts for implementing Long-Term Pollution Prevention Plan. A Long-Term Pollution Prevention Plan is attached to Stormwater Report and is included as an attachment to the Wetlands Notice of Intent. Treatment BMPs subject to the 44% TSS removal pretreatment requirement and the one inch rule for calculating the water quality volume are included, and discharge: is within the Zone II or Interim Wellhead Protection Area is near or to other critical areas is within soils with a rapid infiltration rate (greater than 2.4 inches per hour) involves runoff from land uses with higher potential pollutant loads. The Required Water Quality Volume is reduced through use of the LID site Design Credits. Calculations documenting that the treatment train meets the 80% TSS removal requirement and, if applicable, the 44% TSS removal pretreatment requirement, are provided.

283600swcheck.doc • 04/01/08

Stormwater Report Checklist • Page 5 of 8

Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program

Checklist for Stormwater Report Checklist (continued) Standard 4: Water Quality (continued) The BMP is sized (and calculations provided) based on: The ½” or 1” Water Quality Volume or The equivalent flow rate associated with the Water Quality Volume and documentation is provided showing that the BMP treats the required water quality volume. The applicant proposes to use proprietary BMPs, and documentation supporting use of proprietary BMP and proposed TSS removal rate is provided. This documentation may be in the form of the propriety BMP checklist found in Volume 2, Chapter 4 of the Massachusetts Stormwater Handbook and submitting copies of the TARP Report, STEP Report, and/or other third party studies verifying performance of the proprietary BMPs. A TMDL exists that indicates a need to reduce pollutants other than TSS and documentation showing that the BMPs selected are consistent with the TMDL is provided. Standard 5: Land Uses With Higher Potential Pollutant Loads (LUHPPLs) The NPDES Multi-Sector General Permit covers the land use and the Stormwater Pollution Prevention Plan (SWPPP) has been included with the Stormwater Report. The NPDES Multi-Sector General Permit covers the land use and the SWPPP will be submitted prior to the discharge of stormwater to the post-construction stormwater BMPs. The NPDES Multi-Sector General Permit does not cover the land use. LUHPPLs are located at the site and industry specific source control and pollution prevention measures have been proposed to reduce or eliminate the exposure of LUHPPLs to rain, snow, snow melt and runoff, and been included in the long term Pollution Prevention Plan. All exposure has been eliminated. All exposure has not been eliminated and all BMPs selected are on MassDEP LUHPPL list. The LUHPPL has the potential to generate runoff with moderate to higher concentrations of oil and grease (e.g. all parking lots with >1000 vehicle trips per day) and the treatment train includes an oil grit separator, a filtering bioretention area, a sand filter or equivalent. Standard 6: Critical Areas The discharge is near or to a critical area and the treatment train includes only BMPs that MassDEP has approved for stormwater discharges to or near that particular class of critical area. Critical areas and BMPs are identified in the Stormwater Report.

283600swcheck.doc • 04/01/08

Stormwater Report Checklist • Page 6 of 8

Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program

Checklist for Stormwater Report Checklist (continued) Standard 7: Redevelopments and Other Projects Subject to the Standards only to the maximum extent practicable The project is subject to the Stormwater Management Standards only to the maximum Extent Practicable as a: Limited Project Small Residential Projects: 5-9 single family houses or 5-9 units in a multi-family development provided there is no discharge that may potentially affect a critical area. Small Residential Projects: 2-4 single family houses or 2-4 units in a multi-family development with a discharge to a critical area Marina and/or boatyard provided the hull painting, service and maintenance areas are protected from exposure to rain, snow, snow melt and runoff Bike Path and/or Foot Path Redevelopment Project Redevelopment portion of mix of new and redevelopment. Certain standards are not fully met (Standard No. 1, 8, 9, and 10 must always be fully met) and an explanation of why these standards are not met is contained in the Stormwater Report. The project involves redevelopment and a description of all measures that have been taken to improve existing conditions is provided in the Stormwater Report. The redevelopment checklist found in Volume 2 Chapter 3 of the Massachusetts Stormwater Handbook may be used to document that the proposed stormwater management system (a) complies with Standards 2, 3 and the pretreatment and structural BMP requirements of Standards 4-6 to the maximum extent practicable and (b) improves existing conditions. Standard 8: Construction Period Pollution Prevention and Erosion and Sedimentation Control A Construction Period Pollution Prevention and Erosion and Sedimentation Control Plan must include the following information: • • • • • • • • • • • • • •

Narrative; Construction Period Operation and Maintenance Plan; Names of Persons or Entity Responsible for Plan Compliance; Construction Period Pollution Prevention Measures; Erosion and Sedimentation Control Plan Drawings; Detail drawings and specifications for erosion control BMPs, including sizing calculations; Vegetation Planning; Site Development Plan; Construction Sequencing Plan; Sequencing of Erosion and Sedimentation Controls; Operation and Maintenance of Erosion and Sedimentation Controls; Inspection Schedule; Maintenance Schedule; Inspection and Maintenance Log Form.

A Construction Period Pollution Prevention and Erosion and Sedimentation Control Plan containing the information set forth above has been included in the Stormwater Report.

283600swcheck.doc • 04/01/08

Stormwater Report Checklist • Page 7 of 8

Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program

Checklist for Stormwater Report Checklist (continued) Standard 8: Construction Period Pollution Prevention and Erosion and Sedimentation Control (continued) The project is highly complex and information is included in the Stormwater Report that explains why it is not possible to submit the Construction Period Pollution Prevention and Erosion and Sedimentation Control Plan with the application. A Construction Period Pollution Prevention and Erosion and Sedimentation Control has not been included in the Stormwater Report but will be submitted before land disturbance begins. The project is not covered by a NPDES Construction General Permit. The project is covered by a NPDES Construction General Permit and a copy of the SWPPP is in the Stormwater Report. The project is covered by a NPDES Construction General Permit but no SWPPP been submitted. The SWPPP will be submitted BEFORE land disturbance begins. Standard 9: Operation and Maintenance Plan The Post Construction Operation and Maintenance Plan is included in the Stormwater Report and includes the following information: Name of the stormwater management system owners; Party responsible for operation and maintenance; Schedule for implementation of routine and non-routine maintenance tasks; Plan showing the location of all stormwater BMPs maintenance access areas; Description and delineation of public safety features; Estimated operation and maintenance budget; and Operation and Maintenance Log Form. The responsible party is not the owner of the parcel where the BMP is located and the Stormwater Report includes the following submissions: A copy of the legal instrument (deed, homeowner’s association, utility trust or other legal entity) that establishes the terms of and legal responsibility for the operation and maintenance of the project site stormwater BMPs; A plan and easement deed that allows site access for the legal entity to operate and maintain BMP functions. Standard 10: Prohibition of Illicit Discharges The Long-Term Pollution Prevention Plan includes measures to prevent illicit discharges; An Illicit Discharge Compliance Statement is attached; NO Illicit Discharge Compliance Statement is attached but will be submitted prior to the discharge of any stormwater to post-construction BMPs.

283600swcheck.doc • 04/01/08

Stormwater Report Checklist • Page 8 of 8

Appendix A Soil Data

290600

290700

290800

290900

291000

291100

291200

291300

291400

291500

291600 4676200

290500

71° 31' 26'' W

71° 32' 16'' W

Hydrologic Soil Group—Middlesex County, Massachusetts (2836.00)

42° 12' 37'' N

4674800

4674800

4674900

4674900

4675000

4675000

4675100

4675100

4675200

4675200

4675300

4675300

4675400

4675400

4675500

4675500

4675600

4675600

4675700

4675700

4675800

4675800

4675900

4675900

4676000

4676000

4676100

4676100

4676200

42° 12' 37'' N

4674700

Soil Map may not be valid at this scale.

42° 11' 47'' N

290600

290700

290800

290900

291000

291100

291200

Map Scale: 1:7,480 if printed on A portrait (8.5" x 11") sheet.

N

Meters 600 Feet 0 350 700 1400 2100 Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 19N WGS84 0

100

Natural Resources Conservation Service

200

400

Web Soil Survey National Cooperative Soil Survey

291300

291400

291500

291600 71° 31' 26'' W

71° 32' 16'' W

290500

1/6/2017 Page 1 of 5

42° 11' 47'' N

Hydrologic Soil Group—Middlesex County, Massachusetts (2836.00)

MAP LEGEND Area of Interest (AOI) Area of Interest (AOI) Soils Soil Rating Polygons A A/D B B/D C C/D D Not rated or not available Soil Rating Lines A

MAP INFORMATION The soil surveys that comprise your AOI were mapped at 1:25,000.

C C/D D

Warning: Soil Map may not be valid at this scale.

Not rated or not available

Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale.

Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography

A/D B

Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below.

B/D

Soil Survey Area: Middlesex County, Massachusetts Survey Area Data: Version 16, Sep 14, 2016

C C/D

Soil map units are labeled (as space allows) for map scales 1:50,000 or larger.

D

Date(s) aerial images were photographed: 28, 2014

Not rated or not available Soil Rating Points

Sep 12, 2014—Sep

The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident.

A A/D B B/D

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

1/6/2017 Page 2 of 5

Hydrologic Soil Group—Middlesex County, Massachusetts

2836.00

Hydrologic Soil Group

Hydrologic Soil Group— Summary by Map Unit — Middlesex County, Massachusetts (MA017) Map unit symbol

Map unit name

Rating

51A

Swansea muck, 0 to 1 percent slopes

B/D

71B

Ridgebury fine sandy loam, 3 to 8 percent slopes, extremely stony

73B

Acres in AOI

Percent of AOI 4.2

1.6%

D

20.6

7.9%

Whitman fine sandy loam, 0 to 3 percent slopes, extremely stony

D

27.3

10.5%

106C

Narragansett-HollisRock outcrop complex, 3 to 15 percent slopes

A

9.9

3.8%

302B

Montauk fine sandy loam, 0 to 8 percent slopes, extremely stony

C

0.4

0.1%

302D

Montauk fine sandy C loam, 15 to 35 percent slopes, extremely stony

5.0

1.9%

307B

Paxton fine sandy loam, C 0 to 8 percent slopes, extremely stony

15.2

5.9%

307C

Paxton fine sandy loam, C 8 to 15 percent slopes, extremely stony

1.7

0.6%

317B

Scituate fine sandy loam, 3 to 8 percent slopes, extremely stony

11.7

4.5%

336B

Rainbow silt loam, 3 to 8 C/D percent slopes, very stony

1.6

0.6%

416B

Narragansett silt loam, 3 A to 8 percent slopes, very stony

31.9

12.3%

416C

Narragansett silt loam, 8 A to 15 percent slopes, very stony

56.9

21.9%

422B

Canton fine sandy loam, B 0 to 8 percent slopes, extremely stony

41.3

15.9%

Natural Resources Conservation Service

D

Web Soil Survey National Cooperative Soil Survey

1/6/2017 Page 3 of 5

Hydrologic Soil Group—Middlesex County, Massachusetts

2836.00

Hydrologic Soil Group— Summary by Map Unit — Middlesex County, Massachusetts (MA017) Map unit symbol

Map unit name

Rating

Acres in AOI

Percent of AOI

424B

Canton fine sandy loam, A 3 to 8 percent slopes, extremely bouldery

16.8

6.5%

424C

Canton fine sandy loam, A 8 to 15 percent slopes, extremely bouldery

8.3

3.2%

424D

Canton fine sandy loam, A 15 to 25 percent slopes, extremely bouldery

6.9

2.7%

654

Udorthents, loamy

0.1

0.0%

259.7

100.0%

Totals for Area of Interest

Description Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long-duration storms. The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (A/D, B/D, and C/D). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink-swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes.

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

1/6/2017 Page 4 of 5

Appendix B Pre-Development Hydrologic Analysis

Extreme Precipitation Tables: 42.201°N, 71.531°W

Page 1 of 1

Extreme Precipitation Tables Northeast Regional Climate Center Data represents point estimates calculated from partial duration series. All precipitation amounts are displayed in inches. Smoothing State Location Longitude Latitude Elevation Date/Time

Yes Massachusetts 71.531 degrees West 42.201 degrees North 0 feet Thu, 23 Mar 2017 17:26:16 -0400

Extreme Precipitation Estimates 1yr 2yr 5yr 10yr 25yr 50yr 100yr 200yr 500yr

5min 0.29 0.35 0.42 0.47 0.56 0.63 0.72 0.82 0.99

10min 0.44 0.54 0.65 0.74 0.89 1.01 1.17 1.34 1.63

15min 0.54 0.67 0.81 0.93 1.13 1.29 1.51 1.74 2.13

30min 0.71 0.89 1.09 1.27 1.55 1.81 2.13 2.49 3.09

60min 120min 1hr 2hr 3hr 6hr 12hr 24hr 48hr 0.89 1.13 1yr 0.77 1.07 1.31 1.65 2.10 2.68 2.92 1yr 1.11 1.40 2yr 0.96 1.29 1.63 2.04 2.57 3.23 3.52 2yr 1.39 1.77 5yr 1.20 1.61 2.06 2.59 3.24 4.06 4.48 5yr 1.65 2.11 10yr 1.42 1.90 2.46 3.10 3.88 4.84 5.38 10yr 2.06 2.66 25yr 1.78 2.36 3.11 3.93 4.91 6.09 6.87 25yr 2.44 3.19 50yr 2.11 2.79 3.74 4.72 5.88 7.26 8.26 50yr 2.90 3.80 100yr 2.50 3.30 4.47 5.64 7.02 8.66 9.95 100yr 3.44 4.54 200yr 2.97 3.90 5.35 6.76 8.40 10.32 11.98 200yr 4.32 5.75 500yr 3.73 4.87 6.79 8.58 10.65 13.04 15.32 500yr

1day 2.37 2.86 3.59 4.28 5.39 6.42 7.66 9.14 11.54

2day 2.81 3.38 4.31 5.18 6.60 7.95 9.56 11.52 14.73

4day 3.25 3.89 4.93 5.91 7.50 8.99 10.79 12.94 16.47

7day 3.92 4.62 5.83 6.95 8.78 10.47 12.50 14.93 18.89

10day 4.56 5.25 6.52 7.68 9.54 11.26 13.28 15.67 19.51

1yr 2yr 5yr 10yr 25yr 50yr 100yr 200yr 500yr

Lower Confidence Limits 1yr 2yr 5yr 10yr 25yr 50yr 100yr 200yr 500yr

5min 0.23 0.34 0.38 0.42 0.49 0.54 0.59 0.66 0.75

10min 0.35 0.53 0.59 0.65 0.74 0.82 0.90 0.99 1.12

15min 0.43 0.65 0.73 0.81 0.92 1.02 1.13 1.25 1.44

30min 0.58 0.88 1.00 1.13 1.31 1.46 1.63 1.81 2.09

60min 120min 1hr 2hr 3hr 6hr 12hr 24hr 48hr 0.71 0.94 1yr 0.61 0.92 1.07 1.42 1.85 2.35 2.70 1yr 1.08 1.27 2yr 0.93 1.24 1.45 1.91 2.44 3.13 3.40 2yr 1.28 1.52 5yr 1.10 1.48 1.72 2.25 2.86 3.73 4.12 5yr 1.45 1.73 10yr 1.26 1.69 1.95 2.55 3.22 4.27 4.76 10yr 1.73 2.05 25yr 1.49 2.01 2.31 3.02 3.78 5.11 5.72 25yr 1.97 2.33 50yr 1.70 2.28 2.62 3.42 4.26 5.85 6.59 50yr 2.23 2.65 100yr 1.93 2.59 2.97 3.88 4.81 6.71 7.57 100yr 2.53 3.02 200yr 2.18 2.96 3.38 4.42 5.44 7.70 8.68 200yr 2.97 3.60 500yr 2.56 3.52 3.99 5.25 6.42 9.26 10.39 500yr

1day 2.08 2.77 3.31 3.78 4.53 5.18 5.94 6.81 8.19

2day 2.60 3.27 3.97 4.57 5.50 6.34 7.28 8.35 9.99

4day 2.95 3.76 4.54 5.24 6.34 7.33 8.48 9.80 11.90

7day 3.58 4.46 5.36 6.14 7.36 8.43 9.70 11.14 13.38

10day 4.11 5.08 6.02 6.84 8.07 9.18 10.44 11.89 14.14

1yr 2yr 5yr 10yr 25yr 50yr 100yr 200yr 500yr

Upper Confidence Limits 1yr 2yr 5yr 10yr 25yr 50yr 100yr 200yr 500yr

5min 0.32 0.37 0.45 0.54 0.69 0.82 0.99 1.19 1.55

10min 0.49 0.56 0.70 0.83 1.04 1.25 1.50 1.80 2.30

15min 0.60 0.69 0.87 1.03 1.30 1.56 1.88 2.28 2.96

30min 0.81 0.94 1.19 1.44 1.86 2.24 2.71 3.30 4.30

60min 120min 1hr 2hr 3hr 6hr 12hr 24hr 48hr 1.00 1.19 1yr 0.86 1.17 1.37 1.76 2.30 2.93 3.16 1yr 1.16 1.36 2yr 1.00 1.33 1.57 2.04 2.60 3.36 3.66 2yr 1.51 1.78 5yr 1.31 1.74 2.04 2.62 3.31 4.39 4.86 5yr 1.86 2.19 10yr 1.60 2.14 2.50 3.18 3.96 5.39 6.06 10yr 2.44 2.88 25yr 2.11 2.82 3.27 4.08 5.05 7.07 8.12 25yr 3.01 3.54 50yr 2.60 3.46 4.02 4.94 6.06 8.69 10.12 50yr 3.72 4.36 100yr 3.21 4.26 4.93 5.98 7.28 10.67 12.66 100yr 4.60 5.37 200yr 3.97 5.25 6.07 7.24 8.73 13.10 15.85 200yr 6.11 7.08 500yr 5.28 6.92 7.98 9.32 11.12 17.21 21.36 500yr

1day 2.60 2.97 3.89 4.77 6.26 7.69 9.44 11.59 15.23

2day 3.04 3.52 4.67 5.83 7.80 9.73 12.18 15.24 20.54

4day 3.53 4.05 5.37 6.65 8.85 10.98 13.64 16.93 22.55

7day 4.23 4.80 6.35 7.84 10.39 12.84 15.88 19.65 26.05

10day 4.89 5.44 7.04 8.58 11.15 13.62 16.61 20.23 26.30

1yr 2yr 5yr 10yr 25yr 50yr 100yr 200yr 500yr

Powered by ACIS

file:///G:/Projdata/2836/Transfers/In/NRCC/2017-03-23/output.htm

4/24/2017

Hydrologic Soil Group—Middlesex County, Massachusetts

2836.00

Rating Options Aggregation Method: Dominant Condition Component Percent Cutoff: None Specified Tie-break Rule: Higher

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

1/6/2017 Page 5 of 5

10R 1S E-DP-1 E-DA-1

2S 30R

3S

E-DP-3

E-DA-3

E-DA-2

20R E-DP-2

PRE-DEVELOPMENT

Subcat

Reach

Pond

Link

Routing Diagram for 283600HC001A Prepared by Microsoft, Printed 4/24/2017 HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

2836.00 Pre-Development

283600HC001A Prepared by Microsoft HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Area Listing (selected nodes) Area (acres)

CN

0.081 2.223 0.021 0.077 0.349 0.066 0.127 11.144 9.228 0.256 23.572

39 61 80 98 98 98 98 30 55 77 45

Description (subcatchment-numbers) >75% Grass cover, Good, HSG A (3S) >75% Grass cover, Good, HSG B (2S, 3S) >75% Grass cover, Good, HSG D (3S) Paved parking, HSG A (3S) Paved parking, HSG B (2S, 3S) Paved parking, HSG D (2S, 3S) Unconnected roofs, HSG B (2S, 3S) Woods, Good, HSG A (1S, 2S, 3S) Woods, Good, HSG B (1S, 2S, 3S) Woods, Good, HSG D (1S, 2S, 3S) TOTAL AREA

Printed 4/24/2017 Page 2

2836.00 Pre-Development

283600HC001A Prepared by Microsoft HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Soil Listing (selected nodes) Area (acres)

Soil Group

Subcatchment Numbers

11.302 11.927 0.000 0.343 0.000 23.572

HSG A HSG B HSG C HSG D Other

1S, 2S, 3S 1S, 2S, 3S 1S, 2S, 3S TOTAL AREA

Printed 4/24/2017 Page 3

2836.00 Pre-Development

283600HC001A Printed 4/24/2017 Page 4

Prepared by Microsoft HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Ground Covers (selected nodes) HSG-A (acres)

HSG-B (acres)

HSG-C (acres)

HSG-D (acres)

Other (acres)

Total (acres)

Ground Cover

Subcatchment Numbers

0.081 0.077 0.000 11.144

2.223 0.349 0.127 9.228

0.000 0.000 0.000 0.000

0.021 0.066 0.000 0.256

0.000 0.000 0.000 0.000

2.325 0.492 0.127 20.628

>75% Grass cover, Good Paved parking Unconnected roofs Woods, Good

2S, 3S 2S, 3S 2S, 3S 1S, 2S, 3S

11.302

11.927

0.000

0.343

0.000

23.572

TOTAL AREA

2836.00 Pre-Development

Type III 24-hr 2-YR NRCC Rainfall=3.22"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Printed 4/24/2017 Page 5

Summary for Subcatchment 1S: E-DA-1 [45] Hint: Runoff=Zero Runoff

=

0.00 cfs @

0.00 hrs, Volume=

0.000 af, Depth= 0.00"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2-YR NRCC Rainfall=3.22" Area (ac) 7.407 1.544 0.001 8.952 8.952

CN 30 55 77 34

Description Woods, Good, HSG A Woods, Good, HSG B Woods, Good, HSG D Weighted Average 100.00% Pervious Area

Tc Length Slope (min) (feet) (ft/ft) 13.0 50 0.0690

Velocity (ft/sec) 0.06

11.9

272

0.0231

0.38

6.4

308

0.1045

0.81

31.3

630

Total

Capacity (cfs)

Description Sheet Flow, Sheet Flow Woods: Dense underbrush n= 0.800 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Forest w/Heavy Litter Kv= 2.5 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Forest w/Heavy Litter Kv= 2.5 fps

Summary for Subcatchment 2S: E-DA-2 Runoff

=

0.22 cfs @ 12.95 hrs, Volume=

0.093 af, Depth> 0.17"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2-YR NRCC Rainfall=3.22" Area (ac) 0.105 0.053 0.056 1.417 3.482 0.057 1.229 6.399 6.185 0.214 0.056

CN 98 98 98 30 55 77 61 52

Description Paved parking, HSG B Paved parking, HSG D Unconnected roofs, HSG B Woods, Good, HSG A Woods, Good, HSG B Woods, Good, HSG D >75% Grass cover, Good, HSG B Weighted Average 96.66% Pervious Area 3.34% Impervious Area 26.17% Unconnected

2836.00 Pre-Development

Type III 24-hr 2-YR NRCC Rainfall=3.22"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Tc Length Slope (min) (feet) (ft/ft) 15.5 50 0.0450

Velocity (ft/sec) 0.05

13.2

299

0.0229

0.38

3.6

168

0.0954

0.77

5.8

165

0.0364

0.48

38.1

682

Total

Capacity (cfs)

Printed 4/24/2017 Page 6

Description Sheet Flow, Sheet Flow Woods: Dense underbrush n= 0.800 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Forest w/Heavy Litter Kv= 2.5 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Forest w/Heavy Litter Kv= 2.5 fps Shallow Concentrated Flow, Shallow Concentrated Flow 3 Forest w/Heavy Litter Kv= 2.5 fps

Summary for Subcatchment 3S: E-DA-3 Runoff

=

0.22 cfs @ 12.97 hrs, Volume=

0.104 af, Depth> 0.15"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2-YR NRCC Rainfall=3.22" Area (ac) 0.077 0.244 0.013 0.071 2.320 4.202 0.198 0.081 0.994 0.021 8.221 7.816 0.405 0.071

CN 98 98 98 98 30 55 77 39 61 80 51

Description Paved parking, HSG A Paved parking, HSG B Paved parking, HSG D Unconnected roofs, HSG B Woods, Good, HSG A Woods, Good, HSG B Woods, Good, HSG D >75% Grass cover, Good, HSG A >75% Grass cover, Good, HSG B >75% Grass cover, Good, HSG D Weighted Average 95.07% Pervious Area 4.93% Impervious Area 17.53% Unconnected

Tc Length Slope (min) (feet) (ft/ft) 14.8 50 0.0500

Velocity (ft/sec) 0.06

12.1

347

0.0363

0.48

7.0

301

0.0830

0.72

33.9

698

Total

Capacity (cfs)

Description Sheet Flow, Sheet Flow Woods: Dense underbrush n= 0.800 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Forest w/Heavy Litter Kv= 2.5 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Forest w/Heavy Litter Kv= 2.5 fps

2836.00 Pre-Development

Type III 24-hr 2-YR NRCC Rainfall=3.22"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Printed 4/24/2017 Page 7

Summary for Reach 10R: E-DP-1 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = Inflow = Outflow =

8.952 ac, 0.00% Impervious, Inflow Depth = 0.00" for 2-YR NRCC event 0.00 cfs @ 0.00 hrs, Volume= 0.000 af 0.00 cfs @ 0.00 hrs, Volume= 0.000 af, Atten= 0%, Lag= 0.0 min

Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs

Summary for Reach 20R: E-DP-2 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = Inflow = Outflow =

6.399 ac, 3.34% Impervious, Inflow Depth > 0.17" for 2-YR NRCC event 0.22 cfs @ 12.95 hrs, Volume= 0.093 af 0.22 cfs @ 12.95 hrs, Volume= 0.093 af, Atten= 0%, Lag= 0.0 min

Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs

Summary for Reach 30R: E-DP-3 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = Inflow = Outflow =

8.221 ac, 4.93% Impervious, Inflow Depth > 0.15" for 2-YR NRCC event 0.22 cfs @ 12.97 hrs, Volume= 0.104 af 0.22 cfs @ 12.97 hrs, Volume= 0.104 af, Atten= 0%, Lag= 0.0 min

Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs

2836.00 Pre-Development

Type III 24-hr 10-YR NRCC Rainfall=4.81"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Printed 4/24/2017 Page 8

Summary for Subcatchment 1S: E-DA-1 Runoff

=

0.04 cfs @ 17.18 hrs, Volume=

0.030 af, Depth> 0.04"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10-YR NRCC Rainfall=4.81" Area (ac) 7.407 1.544 0.001 8.952 8.952

CN 30 55 77 34

Description Woods, Good, HSG A Woods, Good, HSG B Woods, Good, HSG D Weighted Average 100.00% Pervious Area

Tc Length Slope (min) (feet) (ft/ft) 13.0 50 0.0690

Velocity (ft/sec) 0.06

11.9

272

0.0231

0.38

6.4

308

0.1045

0.81

31.3

630

Total

Capacity (cfs)

Description Sheet Flow, Sheet Flow Woods: Dense underbrush n= 0.800 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Forest w/Heavy Litter Kv= 2.5 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Forest w/Heavy Litter Kv= 2.5 fps

Summary for Subcatchment 2S: E-DA-2 Runoff

=

1.95 cfs @ 12.67 hrs, Volume=

0.379 af, Depth> 0.71"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10-YR NRCC Rainfall=4.81" Area (ac) 0.105 0.053 0.056 1.417 3.482 0.057 1.229 6.399 6.185 0.214 0.056

CN 98 98 98 30 55 77 61 52

Description Paved parking, HSG B Paved parking, HSG D Unconnected roofs, HSG B Woods, Good, HSG A Woods, Good, HSG B Woods, Good, HSG D >75% Grass cover, Good, HSG B Weighted Average 96.66% Pervious Area 3.34% Impervious Area 26.17% Unconnected

2836.00 Pre-Development

Type III 24-hr 10-YR NRCC Rainfall=4.81"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Tc Length Slope (min) (feet) (ft/ft) 15.5 50 0.0450

Velocity (ft/sec) 0.05

13.2

299

0.0229

0.38

3.6

168

0.0954

0.77

5.8

165

0.0364

0.48

38.1

682

Total

Capacity (cfs)

Printed 4/24/2017 Page 9

Description Sheet Flow, Sheet Flow Woods: Dense underbrush n= 0.800 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Forest w/Heavy Litter Kv= 2.5 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Forest w/Heavy Litter Kv= 2.5 fps Shallow Concentrated Flow, Shallow Concentrated Flow 3 Forest w/Heavy Litter Kv= 2.5 fps

Summary for Subcatchment 3S: E-DA-3 Runoff

=

2.35 cfs @ 12.62 hrs, Volume=

0.451 af, Depth> 0.66"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10-YR NRCC Rainfall=4.81" Area (ac) 0.077 0.244 0.013 0.071 2.320 4.202 0.198 0.081 0.994 0.021 8.221 7.816 0.405 0.071

CN 98 98 98 98 30 55 77 39 61 80 51

Description Paved parking, HSG A Paved parking, HSG B Paved parking, HSG D Unconnected roofs, HSG B Woods, Good, HSG A Woods, Good, HSG B Woods, Good, HSG D >75% Grass cover, Good, HSG A >75% Grass cover, Good, HSG B >75% Grass cover, Good, HSG D Weighted Average 95.07% Pervious Area 4.93% Impervious Area 17.53% Unconnected

Tc Length Slope (min) (feet) (ft/ft) 14.8 50 0.0500

Velocity (ft/sec) 0.06

12.1

347

0.0363

0.48

7.0

301

0.0830

0.72

33.9

698

Total

Capacity (cfs)

Description Sheet Flow, Sheet Flow Woods: Dense underbrush n= 0.800 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Forest w/Heavy Litter Kv= 2.5 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Forest w/Heavy Litter Kv= 2.5 fps

2836.00 Pre-Development

Type III 24-hr 10-YR NRCC Rainfall=4.81"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Printed 4/24/2017 Page 10

Summary for Reach 10R: E-DP-1 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = Inflow = Outflow =

8.952 ac, 0.00% Impervious, Inflow Depth > 0.04" for 10-YR NRCC event 0.04 cfs @ 17.18 hrs, Volume= 0.030 af 0.04 cfs @ 17.18 hrs, Volume= 0.030 af, Atten= 0%, Lag= 0.0 min

Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs

Summary for Reach 20R: E-DP-2 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = Inflow = Outflow =

6.399 ac, 3.34% Impervious, Inflow Depth > 0.71" for 10-YR NRCC event 1.95 cfs @ 12.67 hrs, Volume= 0.379 af 1.95 cfs @ 12.67 hrs, Volume= 0.379 af, Atten= 0%, Lag= 0.0 min

Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs

Summary for Reach 30R: E-DP-3 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = Inflow = Outflow =

8.221 ac, 4.93% Impervious, Inflow Depth > 0.66" for 10-YR NRCC event 2.35 cfs @ 12.62 hrs, Volume= 0.451 af 2.35 cfs @ 12.62 hrs, Volume= 0.451 af, Atten= 0%, Lag= 0.0 min

Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs

2836.00 Pre-Development

Type III 24-hr 25-YR NRCC Rainfall=6.05"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Printed 4/24/2017 Page 11

Summary for Subcatchment 1S: E-DA-1 Runoff

=

0.27 cfs @ 13.97 hrs, Volume=

0.159 af, Depth> 0.21"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 25-YR NRCC Rainfall=6.05" Area (ac) 7.407 1.544 0.001 8.952 8.952

CN 30 55 77 34

Description Woods, Good, HSG A Woods, Good, HSG B Woods, Good, HSG D Weighted Average 100.00% Pervious Area

Tc Length Slope (min) (feet) (ft/ft) 13.0 50 0.0690

Velocity (ft/sec) 0.06

11.9

272

0.0231

0.38

6.4

308

0.1045

0.81

31.3

630

Total

Capacity (cfs)

Description Sheet Flow, Sheet Flow Woods: Dense underbrush n= 0.800 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Forest w/Heavy Litter Kv= 2.5 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Forest w/Heavy Litter Kv= 2.5 fps

Summary for Subcatchment 2S: E-DA-2 Runoff

=

4.21 cfs @ 12.62 hrs, Volume=

0.693 af, Depth> 1.30"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 25-YR NRCC Rainfall=6.05" Area (ac) 0.105 0.053 0.056 1.417 3.482 0.057 1.229 6.399 6.185 0.214 0.056

CN 98 98 98 30 55 77 61 52

Description Paved parking, HSG B Paved parking, HSG D Unconnected roofs, HSG B Woods, Good, HSG A Woods, Good, HSG B Woods, Good, HSG D >75% Grass cover, Good, HSG B Weighted Average 96.66% Pervious Area 3.34% Impervious Area 26.17% Unconnected

2836.00 Pre-Development

Type III 24-hr 25-YR NRCC Rainfall=6.05"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Tc Length Slope (min) (feet) (ft/ft) 15.5 50 0.0450

Velocity (ft/sec) 0.05

13.2

299

0.0229

0.38

3.6

168

0.0954

0.77

5.8

165

0.0364

0.48

38.1

682

Total

Capacity (cfs)

Printed 4/24/2017 Page 12

Description Sheet Flow, Sheet Flow Woods: Dense underbrush n= 0.800 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Forest w/Heavy Litter Kv= 2.5 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Forest w/Heavy Litter Kv= 2.5 fps Shallow Concentrated Flow, Shallow Concentrated Flow 3 Forest w/Heavy Litter Kv= 2.5 fps

Summary for Subcatchment 3S: E-DA-3 Runoff

=

5.29 cfs @ 12.56 hrs, Volume=

0.841 af, Depth> 1.23"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 25-YR NRCC Rainfall=6.05" Area (ac) 0.077 0.244 0.013 0.071 2.320 4.202 0.198 0.081 0.994 0.021 8.221 7.816 0.405 0.071

CN 98 98 98 98 30 55 77 39 61 80 51

Description Paved parking, HSG A Paved parking, HSG B Paved parking, HSG D Unconnected roofs, HSG B Woods, Good, HSG A Woods, Good, HSG B Woods, Good, HSG D >75% Grass cover, Good, HSG A >75% Grass cover, Good, HSG B >75% Grass cover, Good, HSG D Weighted Average 95.07% Pervious Area 4.93% Impervious Area 17.53% Unconnected

Tc Length Slope (min) (feet) (ft/ft) 14.8 50 0.0500

Velocity (ft/sec) 0.06

12.1

347

0.0363

0.48

7.0

301

0.0830

0.72

33.9

698

Total

Capacity (cfs)

Description Sheet Flow, Sheet Flow Woods: Dense underbrush n= 0.800 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Forest w/Heavy Litter Kv= 2.5 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Forest w/Heavy Litter Kv= 2.5 fps

2836.00 Pre-Development

Type III 24-hr 25-YR NRCC Rainfall=6.05"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Printed 4/24/2017 Page 13

Summary for Reach 10R: E-DP-1 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = Inflow = Outflow =

8.952 ac, 0.00% Impervious, Inflow Depth > 0.21" for 25-YR NRCC event 0.27 cfs @ 13.97 hrs, Volume= 0.159 af 0.27 cfs @ 13.97 hrs, Volume= 0.159 af, Atten= 0%, Lag= 0.0 min

Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs

Summary for Reach 20R: E-DP-2 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = Inflow = Outflow =

6.399 ac, 3.34% Impervious, Inflow Depth > 1.30" for 25-YR NRCC event 4.21 cfs @ 12.62 hrs, Volume= 0.693 af 4.21 cfs @ 12.62 hrs, Volume= 0.693 af, Atten= 0%, Lag= 0.0 min

Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs

Summary for Reach 30R: E-DP-3 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = Inflow = Outflow =

8.221 ac, 4.93% Impervious, Inflow Depth > 1.23" for 25-YR NRCC event 5.29 cfs @ 12.56 hrs, Volume= 0.841 af 5.29 cfs @ 12.56 hrs, Volume= 0.841 af, Atten= 0%, Lag= 0.0 min

Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs

2836.00 Pre-Development

Type III 24-hr 100-YR NRCC Rainfall=8.59"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Printed 4/24/2017 Page 14

Summary for Subcatchment 1S: E-DA-1 Runoff

=

3.08 cfs @ 12.64 hrs, Volume=

0.676 af, Depth> 0.91"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100-YR NRCC Rainfall=8.59" Area (ac) 7.407 1.544 0.001 8.952 8.952

CN 30 55 77 34

Description Woods, Good, HSG A Woods, Good, HSG B Woods, Good, HSG D Weighted Average 100.00% Pervious Area

Tc Length Slope (min) (feet) (ft/ft) 13.0 50 0.0690

Velocity (ft/sec) 0.06

11.9

272

0.0231

0.38

6.4

308

0.1045

0.81

31.3

630

Total

Capacity (cfs)

Description Sheet Flow, Sheet Flow Woods: Dense underbrush n= 0.800 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Forest w/Heavy Litter Kv= 2.5 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Forest w/Heavy Litter Kv= 2.5 fps

Summary for Subcatchment 2S: E-DA-2 Runoff

=

10.21 cfs @ 12.57 hrs, Volume=

1.503 af, Depth> 2.82"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100-YR NRCC Rainfall=8.59" Area (ac) 0.105 0.053 0.056 1.417 3.482 0.057 1.229 6.399 6.185 0.214 0.056

CN 98 98 98 30 55 77 61 52

Description Paved parking, HSG B Paved parking, HSG D Unconnected roofs, HSG B Woods, Good, HSG A Woods, Good, HSG B Woods, Good, HSG D >75% Grass cover, Good, HSG B Weighted Average 96.66% Pervious Area 3.34% Impervious Area 26.17% Unconnected

2836.00 Pre-Development

Type III 24-hr 100-YR NRCC Rainfall=8.59"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Tc Length Slope (min) (feet) (ft/ft) 15.5 50 0.0450

Velocity (ft/sec) 0.05

13.2

299

0.0229

0.38

3.6

168

0.0954

0.77

5.8

165

0.0364

0.48

38.1

682

Total

Capacity (cfs)

Printed 4/24/2017 Page 15

Description Sheet Flow, Sheet Flow Woods: Dense underbrush n= 0.800 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Forest w/Heavy Litter Kv= 2.5 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Forest w/Heavy Litter Kv= 2.5 fps Shallow Concentrated Flow, Shallow Concentrated Flow 3 Forest w/Heavy Litter Kv= 2.5 fps

Summary for Subcatchment 3S: E-DA-3 Runoff

=

13.23 cfs @ 12.52 hrs, Volume=

1.855 af, Depth> 2.71"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100-YR NRCC Rainfall=8.59" Area (ac) 0.077 0.244 0.013 0.071 2.320 4.202 0.198 0.081 0.994 0.021 8.221 7.816 0.405 0.071

CN 98 98 98 98 30 55 77 39 61 80 51

Description Paved parking, HSG A Paved parking, HSG B Paved parking, HSG D Unconnected roofs, HSG B Woods, Good, HSG A Woods, Good, HSG B Woods, Good, HSG D >75% Grass cover, Good, HSG A >75% Grass cover, Good, HSG B >75% Grass cover, Good, HSG D Weighted Average 95.07% Pervious Area 4.93% Impervious Area 17.53% Unconnected

Tc Length Slope (min) (feet) (ft/ft) 14.8 50 0.0500

Velocity (ft/sec) 0.06

12.1

347

0.0363

0.48

7.0

301

0.0830

0.72

33.9

698

Total

Capacity (cfs)

Description Sheet Flow, Sheet Flow Woods: Dense underbrush n= 0.800 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Forest w/Heavy Litter Kv= 2.5 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Forest w/Heavy Litter Kv= 2.5 fps

2836.00 Pre-Development

Type III 24-hr 100-YR NRCC Rainfall=8.59"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Printed 4/24/2017 Page 16

Summary for Reach 10R: E-DP-1 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = Inflow = Outflow =

8.952 ac, 0.00% Impervious, Inflow Depth > 0.91" for 100-YR NRCC event 3.08 cfs @ 12.64 hrs, Volume= 0.676 af 3.08 cfs @ 12.64 hrs, Volume= 0.676 af, Atten= 0%, Lag= 0.0 min

Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs

Summary for Reach 20R: E-DP-2 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = Inflow = Outflow =

6.399 ac, 3.34% Impervious, Inflow Depth > 2.82" for 100-YR NRCC event 10.21 cfs @ 12.57 hrs, Volume= 1.503 af 10.21 cfs @ 12.57 hrs, Volume= 1.503 af, Atten= 0%, Lag= 0.0 min

Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs

Summary for Reach 30R: E-DP-3 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = Inflow = Outflow =

8.221 ac, 4.93% Impervious, Inflow Depth > 2.71" for 100-YR NRCC event 13.23 cfs @ 12.52 hrs, Volume= 1.855 af 13.23 cfs @ 12.52 hrs, Volume= 1.855 af, Atten= 0%, Lag= 0.0 min

Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs

Appendix C Post-Development Hydrologic Analysis

Extreme Precipitation Tables: 42.201°N, 71.531°W

Page 1 of 1

Extreme Precipitation Tables Northeast Regional Climate Center Data represents point estimates calculated from partial duration series. All precipitation amounts are displayed in inches. Smoothing State Location Longitude Latitude Elevation Date/Time

Yes Massachusetts 71.531 degrees West 42.201 degrees North 0 feet Thu, 23 Mar 2017 17:26:16 -0400

Extreme Precipitation Estimates 1yr 2yr 5yr 10yr 25yr 50yr 100yr 200yr 500yr

5min 0.29 0.35 0.42 0.47 0.56 0.63 0.72 0.82 0.99

10min 0.44 0.54 0.65 0.74 0.89 1.01 1.17 1.34 1.63

15min 0.54 0.67 0.81 0.93 1.13 1.29 1.51 1.74 2.13

30min 0.71 0.89 1.09 1.27 1.55 1.81 2.13 2.49 3.09

60min 120min 1hr 2hr 3hr 6hr 12hr 24hr 48hr 0.89 1.13 1yr 0.77 1.07 1.31 1.65 2.10 2.68 2.92 1yr 1.11 1.40 2yr 0.96 1.29 1.63 2.04 2.57 3.23 3.52 2yr 1.39 1.77 5yr 1.20 1.61 2.06 2.59 3.24 4.06 4.48 5yr 1.65 2.11 10yr 1.42 1.90 2.46 3.10 3.88 4.84 5.38 10yr 2.06 2.66 25yr 1.78 2.36 3.11 3.93 4.91 6.09 6.87 25yr 2.44 3.19 50yr 2.11 2.79 3.74 4.72 5.88 7.26 8.26 50yr 2.90 3.80 100yr 2.50 3.30 4.47 5.64 7.02 8.66 9.95 100yr 3.44 4.54 200yr 2.97 3.90 5.35 6.76 8.40 10.32 11.98 200yr 4.32 5.75 500yr 3.73 4.87 6.79 8.58 10.65 13.04 15.32 500yr

1day 2.37 2.86 3.59 4.28 5.39 6.42 7.66 9.14 11.54

2day 2.81 3.38 4.31 5.18 6.60 7.95 9.56 11.52 14.73

4day 3.25 3.89 4.93 5.91 7.50 8.99 10.79 12.94 16.47

7day 3.92 4.62 5.83 6.95 8.78 10.47 12.50 14.93 18.89

10day 4.56 5.25 6.52 7.68 9.54 11.26 13.28 15.67 19.51

1yr 2yr 5yr 10yr 25yr 50yr 100yr 200yr 500yr

Lower Confidence Limits 1yr 2yr 5yr 10yr 25yr 50yr 100yr 200yr 500yr

5min 0.23 0.34 0.38 0.42 0.49 0.54 0.59 0.66 0.75

10min 0.35 0.53 0.59 0.65 0.74 0.82 0.90 0.99 1.12

15min 0.43 0.65 0.73 0.81 0.92 1.02 1.13 1.25 1.44

30min 0.58 0.88 1.00 1.13 1.31 1.46 1.63 1.81 2.09

60min 120min 1hr 2hr 3hr 6hr 12hr 24hr 48hr 0.71 0.94 1yr 0.61 0.92 1.07 1.42 1.85 2.35 2.70 1yr 1.08 1.27 2yr 0.93 1.24 1.45 1.91 2.44 3.13 3.40 2yr 1.28 1.52 5yr 1.10 1.48 1.72 2.25 2.86 3.73 4.12 5yr 1.45 1.73 10yr 1.26 1.69 1.95 2.55 3.22 4.27 4.76 10yr 1.73 2.05 25yr 1.49 2.01 2.31 3.02 3.78 5.11 5.72 25yr 1.97 2.33 50yr 1.70 2.28 2.62 3.42 4.26 5.85 6.59 50yr 2.23 2.65 100yr 1.93 2.59 2.97 3.88 4.81 6.71 7.57 100yr 2.53 3.02 200yr 2.18 2.96 3.38 4.42 5.44 7.70 8.68 200yr 2.97 3.60 500yr 2.56 3.52 3.99 5.25 6.42 9.26 10.39 500yr

1day 2.08 2.77 3.31 3.78 4.53 5.18 5.94 6.81 8.19

2day 2.60 3.27 3.97 4.57 5.50 6.34 7.28 8.35 9.99

4day 2.95 3.76 4.54 5.24 6.34 7.33 8.48 9.80 11.90

7day 3.58 4.46 5.36 6.14 7.36 8.43 9.70 11.14 13.38

10day 4.11 5.08 6.02 6.84 8.07 9.18 10.44 11.89 14.14

1yr 2yr 5yr 10yr 25yr 50yr 100yr 200yr 500yr

Upper Confidence Limits 1yr 2yr 5yr 10yr 25yr 50yr 100yr 200yr 500yr

5min 0.32 0.37 0.45 0.54 0.69 0.82 0.99 1.19 1.55

10min 0.49 0.56 0.70 0.83 1.04 1.25 1.50 1.80 2.30

15min 0.60 0.69 0.87 1.03 1.30 1.56 1.88 2.28 2.96

30min 0.81 0.94 1.19 1.44 1.86 2.24 2.71 3.30 4.30

60min 120min 1hr 2hr 3hr 6hr 12hr 24hr 48hr 1.00 1.19 1yr 0.86 1.17 1.37 1.76 2.30 2.93 3.16 1yr 1.16 1.36 2yr 1.00 1.33 1.57 2.04 2.60 3.36 3.66 2yr 1.51 1.78 5yr 1.31 1.74 2.04 2.62 3.31 4.39 4.86 5yr 1.86 2.19 10yr 1.60 2.14 2.50 3.18 3.96 5.39 6.06 10yr 2.44 2.88 25yr 2.11 2.82 3.27 4.08 5.05 7.07 8.12 25yr 3.01 3.54 50yr 2.60 3.46 4.02 4.94 6.06 8.69 10.12 50yr 3.72 4.36 100yr 3.21 4.26 4.93 5.98 7.28 10.67 12.66 100yr 4.60 5.37 200yr 3.97 5.25 6.07 7.24 8.73 13.10 15.85 200yr 6.11 7.08 500yr 5.28 6.92 7.98 9.32 11.12 17.21 21.36 500yr

1day 2.60 2.97 3.89 4.77 6.26 7.69 9.44 11.59 15.23

2day 3.04 3.52 4.67 5.83 7.80 9.73 12.18 15.24 20.54

4day 3.53 4.05 5.37 6.65 8.85 10.98 13.64 16.93 22.55

7day 4.23 4.80 6.35 7.84 10.39 12.84 15.88 19.65 26.05

10day 4.89 5.44 7.04 8.58 11.15 13.62 16.61 20.23 26.30

1yr 2yr 5yr 10yr 25yr 50yr 100yr 200yr 500yr

Powered by ACIS

file:///G:/Projdata/2836/Transfers/In/NRCC/2017-03-23/output.htm

4/24/2017

101AS P-DA-1A

101BS

101AP

110R

P-DA-1B

BASIN-1

P-DP-1

103AS

102AS

P-DA-3A

P-DA-2A

130R

103P

103BS

102BS

102P

120R

P-DP-3

BASIN-3

P-DA-3B

P-DA-2B

BASIN-2

P-DP-2

POST-DEVELOPMENT

Subcat

Reach

Pond

Link

Routing Diagram for 283600HC001A Prepared by Microsoft, Printed 4/26/2017 HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

2836.00 Post-Development

283600HC001A Prepared by Microsoft HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Area Listing (selected nodes) Area (acres)

CN

0.074 2.231 0.021 0.300 7.166 3.970 0.078 0.252 0.013 0.113 0.129 0.053 3.974 4.892 0.316 23.582

39 61 80 96 30 58 98 98 98 98 98 98 30 55 77 46

Description (subcatchment-numbers) >75% Grass cover, Good, HSG A (103AS, 103BS) >75% Grass cover, Good, HSG B (102AS, 103AS, 103BS) >75% Grass cover, Good, HSG D (103AS) Gravel surface, HSG B (101BS, 102BS, 103BS) Meadow, non-grazed, HSG A (101AS, 101BS, 103AS, 103BS) Meadow, non-grazed, HSG B (101BS, 102AS, 102BS, 103BS) Paved parking, HSG A (103AS, 103BS) Paved parking, HSG B (103BS) Paved parking, HSG D (103AS) Unconnected pavement, HSG B (101BS, 102AS) Unconnected roofs, HSG B (102AS, 103BS) Water Surface, HSG B (102AS) Woods, Good, HSG A (101AS, 101BS, 102AS, 103AS, 103BS) Woods, Good, HSG B (101BS, 102AS, 102BS, 103AS, 103BS) Woods, Good, HSG D (101AS, 102AS, 103AS) TOTAL AREA

Printed 4/26/2017 Page 2

2836.00 Post-Development

283600HC001A Prepared by Microsoft HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Soil Listing (selected nodes) Area (acres)

Soil Group

Subcatchment Numbers

11.292 11.940 0.000 0.350 0.000 23.582

HSG A HSG B HSG C HSG D Other

101AS, 101BS, 102AS, 103AS, 103BS 101BS, 102AS, 102BS, 103AS, 103BS 101AS, 102AS, 103AS TOTAL AREA

Printed 4/26/2017 Page 3

2836.00 Post-Development

283600HC001A Printed 4/26/2017 Page 4

Prepared by Microsoft HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Ground Covers (selected nodes) HSG-A (acres)

HSG-B (acres)

HSG-C (acres)

HSG-D (acres)

Other (acres)

Total (acres)

0.074

2.231

0.000

0.021

0.000

2.326

0.000

0.300

0.000

0.000

0.000

0.300

7.166

3.970

0.000

0.000

0.000

11.136

0.078

0.252

0.000

0.013

0.000

0.343

0.000

0.113

0.000

0.000

0.000

0.113

0.000

0.129

0.000

0.000

0.000

0.129

0.000 3.974

0.053 4.892

0.000 0.000

0.000 0.316

0.000 0.000

0.053 9.182

11.292

11.940

0.000

0.350

0.000

23.582

Ground Cover

Subcatchment Numbers

>75% Grass cover, Good 102AS, 103AS, 103BS Gravel surface 101BS, 102BS, 103BS Meadow, non-grazed 101AS, 101BS, 102AS, 102BS, 103AS, 103BS Paved parking 103AS, 103BS Unconnected pavement 101BS, 102AS Unconnected roofs 102AS, 103BS Water Surface 102AS Woods, Good 101AS, 101BS, 102AS, 102BS, 103AS, 103BS TOTAL AREA

2836.00 Post-Development

Type III 24-hr 2-YR NRCC Rainfall=3.22"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Printed 4/26/2017 Page 5

Summary for Subcatchment 101AS: P-DA-1A [45] Hint: Runoff=Zero Runoff

=

0.00 cfs @

0.00 hrs, Volume=

0.000 af, Depth= 0.00"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2-YR NRCC Rainfall=3.22" Area (ac) 1.479 0.001 0.403 1.883 1.883

CN 30 77 30 30

Tc Length (min) (feet) 6.0

Description Woods, Good, HSG A Woods, Good, HSG D Meadow, non-grazed, HSG A Weighted Average 100.00% Pervious Area Slope (ft/ft)

Velocity (ft/sec)

Capacity (cfs)

Description Direct Entry, Minimum

Summary for Subcatchment 101BS: P-DA-1B [45] Hint: Runoff=Zero Runoff

=

0.00 cfs @

0.00 hrs, Volume=

0.000 af, Depth= 0.00"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2-YR NRCC Rainfall=3.22" Area (ac) 0.452 2.021 5.336 0.363 0.008 0.051 8.231 8.223 0.008 0.008

CN 30 55 30 58 98 96 38

Description Woods, Good, HSG A Woods, Good, HSG B Meadow, non-grazed, HSG A Meadow, non-grazed, HSG B Unconnected pavement, HSG B Gravel surface, HSG B Weighted Average 99.90% Pervious Area 0.10% Impervious Area 100.00% Unconnected

Tc Length Slope (min) (feet) (ft/ft) 13.0 50 0.0690

Velocity (ft/sec) 0.06

12.8

292

0.0231

0.38

5.4

260

0.1045

0.81

31.2

602

Total

Capacity (cfs)

Description Sheet Flow, Sheet Flow Woods: Dense underbrush n= 0.800 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Forest w/Heavy Litter Kv= 2.5 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Forest w/Heavy Litter Kv= 2.5 fps

2836.00 Post-Development

Type III 24-hr 2-YR NRCC Rainfall=3.22"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Printed 4/26/2017 Page 6

Summary for Subcatchment 102AS: P-DA-2A Runoff

=

0.19 cfs @ 12.49 hrs, Volume=

0.057 af, Depth> 0.18"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2-YR NRCC Rainfall=3.22" Area (ac) 0.105 0.053 0.057 1.156 0.773 0.117 1.205 0.432 3.898 3.683 0.215 0.162

CN 98 98 98 30 55 77 61 58 53

Adj

52

Tc Length Slope (min) (feet) (ft/ft) 3.8 50 0.0514

Description Unconnected pavement, HSG B Water Surface, HSG B Unconnected roofs, HSG B Woods, Good, HSG A Woods, Good, HSG B Woods, Good, HSG D >75% Grass cover, Good, HSG B Meadow, non-grazed, HSG B Weighted Average, UI Adjusted 94.48% Pervious Area 5.52% Impervious Area 75.35% Unconnected Velocity (ft/sec) 0.22

4.3

208

0.0133

0.81

1.3

168

0.0954

2.16

2.2

121

0.0165

0.90

11.6

547

Total

Capacity (cfs)

Description Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Short Grass Pasture Kv= 7.0 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Short Grass Pasture Kv= 7.0 fps Shallow Concentrated Flow, Shallow Concentrated Flow 3 Short Grass Pasture Kv= 7.0 fps

Summary for Subcatchment 102BS: P-DA-2B Runoff

=

0.39 cfs @ 12.20 hrs, Volume=

0.051 af, Depth> 0.45"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2-YR NRCC Rainfall=3.22" Area (ac) 0.106 1.138 0.106 1.350 1.350

CN 55 58 96 61

Description Woods, Good, HSG B Meadow, non-grazed, HSG B Gravel surface, HSG B Weighted Average 100.00% Pervious Area

2836.00 Post-Development

Type III 24-hr 2-YR NRCC Rainfall=3.22"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Tc Length Slope (min) (feet) (ft/ft) 6.4 50 0.0144 3.4

172

0.1 9.9

Velocity (ft/sec) 0.13

0.0144

0.84

15 0.2000

3.13

237

Capacity (cfs)

Printed 4/26/2017 Page 7

Description Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Short Grass Pasture Kv= 7.0 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Short Grass Pasture Kv= 7.0 fps

Total

Summary for Subcatchment 103AS: P-DA-3A Runoff

=

0.00 cfs @ 21.38 hrs, Volume=

0.002 af, Depth> 0.01"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2-YR NRCC Rainfall=3.22" Area (ac) 0.022 0.013 0.670 0.068 0.198 0.020 0.044 0.021 0.236 1.292 1.257 0.035

CN 98 98 30 55 77 39 61 80 30 42

Tc Length (min) (feet) 6.0

Description Paved parking, HSG A Paved parking, HSG D Woods, Good, HSG A Woods, Good, HSG B Woods, Good, HSG D >75% Grass cover, Good, HSG A >75% Grass cover, Good, HSG B >75% Grass cover, Good, HSG D Meadow, non-grazed, HSG A Weighted Average 97.29% Pervious Area 2.71% Impervious Area Slope (ft/ft)

Velocity (ft/sec)

Capacity (cfs)

Description Direct Entry, Minimum

Summary for Subcatchment 103BS: P-DA-3B Runoff

=

0.54 cfs @ 12.51 hrs, Volume=

0.131 af, Depth> 0.23"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2-YR NRCC Rainfall=3.22"

2836.00 Post-Development

Type III 24-hr 2-YR NRCC Rainfall=3.22"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Area (ac) 0.056 0.252 0.072 0.217 1.924 0.054 0.982 1.191 2.037 0.143 6.928 6.548 0.380 0.072

CN 98 98 98 30 55 39 61 30 58 96 55

Adj

54

Tc Length Slope (min) (feet) (ft/ft) 9.8 50 0.0050

Description Paved parking, HSG A Paved parking, HSG B Unconnected roofs, HSG B Woods, Good, HSG A Woods, Good, HSG B >75% Grass cover, Good, HSG A >75% Grass cover, Good, HSG B Meadow, non-grazed, HSG A Meadow, non-grazed, HSG B Gravel surface, HSG B Weighted Average, UI Adjusted 94.52% Pervious Area 5.48% Impervious Area 18.95% Unconnected Velocity (ft/sec) 0.09

4.3

347

0.0363

1.33

1.8

192

0.0625

1.75

31 0.0955

2.16

0.2 16.1

620

Printed 4/26/2017 Page 8

Capacity (cfs)

Description Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Short Grass Pasture Kv= 7.0 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Short Grass Pasture Kv= 7.0 fps Shallow Concentrated Flow, Shallow Concentrated Flow 3 Short Grass Pasture Kv= 7.0 fps

Total

Summary for Reach 110R: P-DP-1 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = Inflow = Outflow =

10.114 ac, 0.08% Impervious, Inflow Depth = 0.00" for 2-YR NRCC event 0.00 cfs @ 0.00 hrs, Volume= 0.000 af 0.00 cfs @ 0.00 hrs, Volume= 0.000 af, Atten= 0%, Lag= 0.0 min

Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs

Summary for Reach 120R: P-DP-2 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = Inflow = Outflow =

5.248 ac, 4.10% Impervious, Inflow Depth > 0.13" for 2-YR NRCC event 0.19 cfs @ 12.49 hrs, Volume= 0.057 af 0.19 cfs @ 12.49 hrs, Volume= 0.057 af, Atten= 0%, Lag= 0.0 min

Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs

2836.00 Post-Development

Type III 24-hr 2-YR NRCC Rainfall=3.22"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Printed 4/26/2017 Page 9

Summary for Reach 130R: P-DP-3 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = Inflow = Outflow =

8.220 ac, 5.05% Impervious, Inflow Depth > 0.11" for 2-YR NRCC event 0.14 cfs @ 16.22 hrs, Volume= 0.072 af 0.14 cfs @ 16.22 hrs, Volume= 0.072 af, Atten= 0%, Lag= 0.0 min

Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs

Summary for Pond 101AP: BASIN-1 Inflow Area = Inflow = Outflow = Primary =

8.231 ac, 0.10% Impervious, Inflow Depth = 0.00" for 2-YR NRCC event 0.00 cfs @ 0.00 hrs, Volume= 0.000 af 0.00 cfs @ 0.00 hrs, Volume= 0.000 af, Atten= 0%, Lag= 0.0 min 0.00 cfs @ 0.00 hrs, Volume= 0.000 af

Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 493.00' @ 0.00 hrs Surf.Area= 3,844 sf Storage= 0 cf Plug-Flow detention time= (not calculated: initial storage exceeds outflow) Center-of-Mass det. time= (not calculated: no inflow) Volume #1

Invert 493.00'

Elevation (feet) 493.00 494.00 496.00 Device #1

Avail.Storage 30,824 cf

Surf.Area (sq-ft) 3,844 8,790 15,717

Routing Primary

Invert 495.00'

#2

Primary

494.00'

#3

Primary

493.75'

Storage Description Custom Stage Data (Prismatic)Listed below (Recalc)

Inc.Store (cubic-feet) 0 6,317 24,507

Cum.Store (cubic-feet) 0 6,317 30,824

Outlet Devices 20.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 12.0" Round Culvert L= 30.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 494.00' / 493.00' S= 0.0333 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf 12.0" Round Culvert L= 30.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 493.75' / 493.00' S= 0.0250 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf

Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=493.00' (Free Discharge) 1=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) 2=Culvert ( Controls 0.00 cfs) 3=Culvert ( Controls 0.00 cfs)

2836.00 Post-Development

Type III 24-hr 2-YR NRCC Rainfall=3.22"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Printed 4/26/2017 Page 10

Summary for Pond 102P: BASIN-2 Inflow Area = Inflow = Outflow = Primary =

1.350 ac, 0.00% Impervious, Inflow Depth > 0.45" for 2-YR NRCC event 0.39 cfs @ 12.20 hrs, Volume= 0.051 af 0.00 cfs @ 0.00 hrs, Volume= 0.000 af, Atten= 100%, Lag= 0.0 min 0.00 cfs @ 0.00 hrs, Volume= 0.000 af

Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 526.21' @ 24.00 hrs Surf.Area= 11,073 sf Storage= 2,207 cf Plug-Flow detention time= (not calculated: initial storage exceeds outflow) Center-of-Mass det. time= (not calculated: no outflow) Volume #1

Invert 526.00'

Elevation (feet) 526.00 528.00 Device #1 #2

Avail.Storage 28,174 cf

Surf.Area (sq-ft) 10,288 17,886

Storage Description Basin (Prismatic) Listed below (Recalc)

Inc.Store (cubic-feet) 0 28,174

Routing Primary

Invert 527.00'

Primary

526.25'

Cum.Store (cubic-feet) 0 28,174

Outlet Devices 20.0' long x 10.0' breadth Riprap Overflow Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 6.0" Round Culvert L= 60.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 526.25' / 525.00' S= 0.0208 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.20 sf

Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=526.00' (Free Discharge) 1=Riprap Overflow Weir ( Controls 0.00 cfs) 2=Culvert ( Controls 0.00 cfs)

Summary for Pond 103P: BASIN-3 Inflow Area = Inflow = Outflow = Primary =

6.928 ac, 0.54 cfs @ 0.13 cfs @ 0.13 cfs @

5.48% Impervious, Inflow Depth > 0.23" for 2-YR NRCC event 12.51 hrs, Volume= 0.131 af 16.20 hrs, Volume= 0.070 af, Atten= 75%, Lag= 221.5 min 16.20 hrs, Volume= 0.070 af

Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 501.52' @ 16.20 hrs Surf.Area= 6,278 sf Storage= 2,867 cf Plug-Flow detention time= 315.9 min calculated for 0.070 af (54% of inflow) Center-of-Mass det. time= 163.4 min ( 1,131.9 - 968.6 )

2836.00 Post-Development

Type III 24-hr 2-YR NRCC Rainfall=3.22"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Volume #1

Invert 501.00'

Elevation (feet) 501.00 502.00 504.00 Device #1

Avail.Storage 28,347 cf

Surf.Area (sq-ft) 4,660 7,748 14,395

Routing Primary

Invert 503.00'

#2

Primary

501.42'

#3

Primary

501.42'

Printed 4/26/2017 Page 11

Storage Description Custom Stage Data (Prismatic)Listed below (Recalc)

Inc.Store (cubic-feet) 0 6,204 22,143

Cum.Store (cubic-feet) 0 6,204 28,347

Outlet Devices 20.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 12.0" Round Culvert X 2.00 L= 35.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 501.42' / 500.00' S= 0.0406 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf 15.0" Round Culvert L= 35.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 501.42' / 500.00' S= 0.0406 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 1.23 sf

Primary OutFlow Max=0.13 cfs @ 16.20 hrs HW=501.52' (Free Discharge) 1=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) 2=Culvert (Inlet Controls 0.08 cfs @ 0.97 fps) 3=Culvert (Inlet Controls 0.05 cfs @ 0.97 fps)

2836.00 Post-Development

Type III 24-hr 10-YR NRCC Rainfall=4.81"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Printed 4/26/2017 Page 12

Summary for Subcatchment 101AS: P-DA-1A [73] Warning: Peak may fall outside time span Runoff

=

0.00 cfs @ 24.00 hrs, Volume=

0.000 af, Depth> 0.00"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10-YR NRCC Rainfall=4.81" Area (ac) 1.479 0.001 0.403 1.883 1.883

CN 30 77 30 30

Tc Length (min) (feet) 6.0

Description Woods, Good, HSG A Woods, Good, HSG D Meadow, non-grazed, HSG A Weighted Average 100.00% Pervious Area Slope (ft/ft)

Velocity (ft/sec)

Capacity (cfs)

Description Direct Entry, Minimum

Summary for Subcatchment 101BS: P-DA-1B Runoff

=

0.15 cfs @ 14.94 hrs, Volume=

0.090 af, Depth> 0.13"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10-YR NRCC Rainfall=4.81" Area (ac) 0.452 2.021 5.336 0.363 0.008 0.051 8.231 8.223 0.008 0.008

CN 30 55 30 58 98 96 38

Description Woods, Good, HSG A Woods, Good, HSG B Meadow, non-grazed, HSG A Meadow, non-grazed, HSG B Unconnected pavement, HSG B Gravel surface, HSG B Weighted Average 99.90% Pervious Area 0.10% Impervious Area 100.00% Unconnected

Tc Length Slope (min) (feet) (ft/ft) 13.0 50 0.0690

Velocity (ft/sec) 0.06

12.8

292

0.0231

0.38

5.4

260

0.1045

0.81

31.2

602

Total

Capacity (cfs)

Description Sheet Flow, Sheet Flow Woods: Dense underbrush n= 0.800 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Forest w/Heavy Litter Kv= 2.5 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Forest w/Heavy Litter Kv= 2.5 fps

2836.00 Post-Development

Type III 24-hr 10-YR NRCC Rainfall=4.81"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Printed 4/26/2017 Page 13

Summary for Subcatchment 102AS: P-DA-2A Runoff

=

1.81 cfs @ 12.22 hrs, Volume=

0.233 af, Depth> 0.72"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10-YR NRCC Rainfall=4.81" Area (ac) 0.105 0.053 0.057 1.156 0.773 0.117 1.205 0.432 3.898 3.683 0.215 0.162

CN 98 98 98 30 55 77 61 58 53

Adj

52

Tc Length Slope (min) (feet) (ft/ft) 3.8 50 0.0514

Description Unconnected pavement, HSG B Water Surface, HSG B Unconnected roofs, HSG B Woods, Good, HSG A Woods, Good, HSG B Woods, Good, HSG D >75% Grass cover, Good, HSG B Meadow, non-grazed, HSG B Weighted Average, UI Adjusted 94.48% Pervious Area 5.52% Impervious Area 75.35% Unconnected Velocity (ft/sec) 0.22

4.3

208

0.0133

0.81

1.3

168

0.0954

2.16

2.2

121

0.0165

0.90

11.6

547

Total

Capacity (cfs)

Description Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Short Grass Pasture Kv= 7.0 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Short Grass Pasture Kv= 7.0 fps Shallow Concentrated Flow, Shallow Concentrated Flow 3 Short Grass Pasture Kv= 7.0 fps

Summary for Subcatchment 102BS: P-DA-2B Runoff

=

1.54 cfs @ 12.16 hrs, Volume=

0.141 af, Depth> 1.25"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10-YR NRCC Rainfall=4.81" Area (ac) 0.106 1.138 0.106 1.350 1.350

CN 55 58 96 61

Description Woods, Good, HSG B Meadow, non-grazed, HSG B Gravel surface, HSG B Weighted Average 100.00% Pervious Area

2836.00 Post-Development

Type III 24-hr 10-YR NRCC Rainfall=4.81"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Tc Length Slope (min) (feet) (ft/ft) 6.4 50 0.0144 3.4

172

0.1 9.9

Velocity (ft/sec) 0.13

0.0144

0.84

15 0.2000

3.13

237

Capacity (cfs)

Printed 4/26/2017 Page 14

Description Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Short Grass Pasture Kv= 7.0 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Short Grass Pasture Kv= 7.0 fps

Total

Summary for Subcatchment 103AS: P-DA-3A Runoff

=

0.10 cfs @ 12.41 hrs, Volume=

0.028 af, Depth> 0.26"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10-YR NRCC Rainfall=4.81" Area (ac) 0.022 0.013 0.670 0.068 0.198 0.020 0.044 0.021 0.236 1.292 1.257 0.035

CN 98 98 30 55 77 39 61 80 30 42

Tc Length (min) (feet) 6.0

Description Paved parking, HSG A Paved parking, HSG D Woods, Good, HSG A Woods, Good, HSG B Woods, Good, HSG D >75% Grass cover, Good, HSG A >75% Grass cover, Good, HSG B >75% Grass cover, Good, HSG D Meadow, non-grazed, HSG A Weighted Average 97.29% Pervious Area 2.71% Impervious Area Slope (ft/ft)

Velocity (ft/sec)

Capacity (cfs)

Description Direct Entry, Minimum

Summary for Subcatchment 103BS: P-DA-3B Runoff

=

3.64 cfs @ 12.29 hrs, Volume=

0.477 af, Depth> 0.83"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10-YR NRCC Rainfall=4.81"

2836.00 Post-Development

Type III 24-hr 10-YR NRCC Rainfall=4.81"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Area (ac) 0.056 0.252 0.072 0.217 1.924 0.054 0.982 1.191 2.037 0.143 6.928 6.548 0.380 0.072

CN 98 98 98 30 55 39 61 30 58 96 55

Adj

54

Tc Length Slope (min) (feet) (ft/ft) 9.8 50 0.0050

Description Paved parking, HSG A Paved parking, HSG B Unconnected roofs, HSG B Woods, Good, HSG A Woods, Good, HSG B >75% Grass cover, Good, HSG A >75% Grass cover, Good, HSG B Meadow, non-grazed, HSG A Meadow, non-grazed, HSG B Gravel surface, HSG B Weighted Average, UI Adjusted 94.52% Pervious Area 5.48% Impervious Area 18.95% Unconnected Velocity (ft/sec) 0.09

4.3

347

0.0363

1.33

1.8

192

0.0625

1.75

31 0.0955

2.16

0.2 16.1

620

Printed 4/26/2017 Page 15

Capacity (cfs)

Description Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Short Grass Pasture Kv= 7.0 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Short Grass Pasture Kv= 7.0 fps Shallow Concentrated Flow, Shallow Concentrated Flow 3 Short Grass Pasture Kv= 7.0 fps

Total

Summary for Reach 110R: P-DP-1 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = Inflow = Outflow =

10.114 ac, 0.08% Impervious, Inflow Depth > 0.00" for 10-YR NRCC event 0.00 cfs @ 24.00 hrs, Volume= 0.000 af 0.00 cfs @ 24.00 hrs, Volume= 0.000 af, Atten= 0%, Lag= 0.0 min

Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs

Summary for Reach 120R: P-DP-2 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = Inflow = Outflow =

5.248 ac, 4.10% Impervious, Inflow Depth > 0.63" for 10-YR NRCC event 1.81 cfs @ 12.22 hrs, Volume= 0.277 af 1.81 cfs @ 12.22 hrs, Volume= 0.277 af, Atten= 0%, Lag= 0.0 min

Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs

2836.00 Post-Development

Type III 24-hr 10-YR NRCC Rainfall=4.81"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Printed 4/26/2017 Page 16

Summary for Reach 130R: P-DP-3 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = Inflow = Outflow =

8.220 ac, 5.05% Impervious, Inflow Depth > 0.64" for 10-YR NRCC event 1.85 cfs @ 12.69 hrs, Volume= 0.439 af 1.85 cfs @ 12.69 hrs, Volume= 0.439 af, Atten= 0%, Lag= 0.0 min

Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs

Summary for Pond 101AP: BASIN-1 Inflow Area = Inflow = Outflow = Primary =

8.231 ac, 0.10% Impervious, Inflow Depth > 0.13" for 10-YR NRCC event 0.15 cfs @ 14.94 hrs, Volume= 0.090 af 0.00 cfs @ 0.00 hrs, Volume= 0.000 af, Atten= 100%, Lag= 0.0 min 0.00 cfs @ 0.00 hrs, Volume= 0.000 af

Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 493.70' @ 24.00 hrs Surf.Area= 7,305 sf Storage= 3,901 cf Plug-Flow detention time= (not calculated: initial storage exceeds outflow) Center-of-Mass det. time= (not calculated: no outflow) Volume #1

Invert 493.00'

Elevation (feet) 493.00 494.00 496.00 Device #1

Avail.Storage 30,824 cf

Surf.Area (sq-ft) 3,844 8,790 15,717

Routing Primary

Invert 495.00'

#2

Primary

494.00'

#3

Primary

493.75'

Storage Description Custom Stage Data (Prismatic)Listed below (Recalc)

Inc.Store (cubic-feet) 0 6,317 24,507

Cum.Store (cubic-feet) 0 6,317 30,824

Outlet Devices 20.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 12.0" Round Culvert L= 30.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 494.00' / 493.00' S= 0.0333 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf 12.0" Round Culvert L= 30.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 493.75' / 493.00' S= 0.0250 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf

Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=493.00' (Free Discharge) 1=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) 2=Culvert ( Controls 0.00 cfs) 3=Culvert ( Controls 0.00 cfs)

2836.00 Post-Development

Type III 24-hr 10-YR NRCC Rainfall=4.81"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Printed 4/26/2017 Page 17

Summary for Pond 102P: BASIN-2 Inflow Area = Inflow = Outflow = Primary =

1.350 ac, 1.54 cfs @ 0.06 cfs @ 0.06 cfs @

0.00% Impervious, Inflow Depth > 1.25" for 10-YR NRCC event 12.16 hrs, Volume= 0.141 af 18.05 hrs, Volume= 0.044 af, Atten= 96%, Lag= 353.3 min 18.05 hrs, Volume= 0.044 af

Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 526.40' @ 18.05 hrs Surf.Area= 11,819 sf Storage= 4,455 cf Plug-Flow detention time= 419.6 min calculated for 0.043 af (31% of inflow) Center-of-Mass det. time= 271.6 min ( 1,148.9 - 877.4 ) Volume #1

Invert 526.00'

Elevation (feet) 526.00 528.00 Device #1 #2

Avail.Storage 28,174 cf

Surf.Area (sq-ft) 10,288 17,886

Storage Description Basin (Prismatic) Listed below (Recalc)

Inc.Store (cubic-feet) 0 28,174

Routing Primary

Invert 527.00'

Primary

526.25'

Cum.Store (cubic-feet) 0 28,174

Outlet Devices 20.0' long x 10.0' breadth Riprap Overflow Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 6.0" Round Culvert L= 60.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 526.25' / 525.00' S= 0.0208 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.20 sf

Primary OutFlow Max=0.06 cfs @ 18.05 hrs HW=526.40' (Free Discharge) 1=Riprap Overflow Weir ( Controls 0.00 cfs) 2=Culvert (Inlet Controls 0.06 cfs @ 1.18 fps)

Summary for Pond 103P: BASIN-3 Inflow Area = Inflow = Outflow = Primary =

6.928 ac, 3.64 cfs @ 1.78 cfs @ 1.78 cfs @

5.48% Impervious, Inflow Depth > 0.83" for 10-YR NRCC event 12.29 hrs, Volume= 0.477 af 12.69 hrs, Volume= 0.410 af, Atten= 51%, Lag= 24.1 min 12.69 hrs, Volume= 0.410 af

Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 501.82' @ 12.69 hrs Surf.Area= 7,201 sf Storage= 4,880 cf Plug-Flow detention time= 108.1 min calculated for 0.410 af (86% of inflow) Center-of-Mass det. time= 45.8 min ( 952.9 - 907.2 )

2836.00 Post-Development

Type III 24-hr 10-YR NRCC Rainfall=4.81"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Volume #1

Invert 501.00'

Elevation (feet) 501.00 502.00 504.00 Device #1

Avail.Storage 28,347 cf

Surf.Area (sq-ft) 4,660 7,748 14,395

Routing Primary

Invert 503.00'

#2

Primary

501.42'

#3

Primary

501.42'

Printed 4/26/2017 Page 18

Storage Description Custom Stage Data (Prismatic)Listed below (Recalc)

Inc.Store (cubic-feet) 0 6,204 22,143

Cum.Store (cubic-feet) 0 6,204 28,347

Outlet Devices 20.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 12.0" Round Culvert X 2.00 L= 35.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 501.42' / 500.00' S= 0.0406 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf 15.0" Round Culvert L= 35.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 501.42' / 500.00' S= 0.0406 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 1.23 sf

Primary OutFlow Max=1.78 cfs @ 12.69 hrs HW=501.82' (Free Discharge) 1=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) 2=Culvert (Inlet Controls 1.13 cfs @ 1.91 fps) 3=Culvert (Inlet Controls 0.65 cfs @ 1.91 fps)

2836.00 Post-Development

Type III 24-hr 25-YR NRCC Rainfall=6.05"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Printed 4/26/2017 Page 19

Summary for Subcatchment 101AS: P-DA-1A Runoff

=

0.02 cfs @ 15.43 hrs, Volume=

0.012 af, Depth> 0.08"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 25-YR NRCC Rainfall=6.05" Area (ac) 1.479 0.001 0.403 1.883 1.883

CN 30 77 30 30

Tc Length (min) (feet) 6.0

Description Woods, Good, HSG A Woods, Good, HSG D Meadow, non-grazed, HSG A Weighted Average 100.00% Pervious Area Slope (ft/ft)

Velocity (ft/sec)

Capacity (cfs)

Description Direct Entry, Minimum

Summary for Subcatchment 101BS: P-DA-1B Runoff

=

0.86 cfs @ 12.75 hrs, Volume=

0.274 af, Depth> 0.40"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 25-YR NRCC Rainfall=6.05" Area (ac) 0.452 2.021 5.336 0.363 0.008 0.051 8.231 8.223 0.008 0.008

CN 30 55 30 58 98 96 38

Description Woods, Good, HSG A Woods, Good, HSG B Meadow, non-grazed, HSG A Meadow, non-grazed, HSG B Unconnected pavement, HSG B Gravel surface, HSG B Weighted Average 99.90% Pervious Area 0.10% Impervious Area 100.00% Unconnected

Tc Length Slope (min) (feet) (ft/ft) 13.0 50 0.0690

Velocity (ft/sec) 0.06

12.8

292

0.0231

0.38

5.4

260

0.1045

0.81

31.2

602

Total

Capacity (cfs)

Description Sheet Flow, Sheet Flow Woods: Dense underbrush n= 0.800 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Forest w/Heavy Litter Kv= 2.5 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Forest w/Heavy Litter Kv= 2.5 fps

2836.00 Post-Development

Type III 24-hr 25-YR NRCC Rainfall=6.05"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Printed 4/26/2017 Page 20

Summary for Subcatchment 102AS: P-DA-2A Runoff

=

4.10 cfs @ 12.19 hrs, Volume=

0.426 af, Depth> 1.31"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 25-YR NRCC Rainfall=6.05" Area (ac) 0.105 0.053 0.057 1.156 0.773 0.117 1.205 0.432 3.898 3.683 0.215 0.162

CN 98 98 98 30 55 77 61 58 53

Adj

52

Tc Length Slope (min) (feet) (ft/ft) 3.8 50 0.0514

Description Unconnected pavement, HSG B Water Surface, HSG B Unconnected roofs, HSG B Woods, Good, HSG A Woods, Good, HSG B Woods, Good, HSG D >75% Grass cover, Good, HSG B Meadow, non-grazed, HSG B Weighted Average, UI Adjusted 94.48% Pervious Area 5.52% Impervious Area 75.35% Unconnected Velocity (ft/sec) 0.22

4.3

208

0.0133

0.81

1.3

168

0.0954

2.16

2.2

121

0.0165

0.90

11.6

547

Total

Capacity (cfs)

Description Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Short Grass Pasture Kv= 7.0 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Short Grass Pasture Kv= 7.0 fps Shallow Concentrated Flow, Shallow Concentrated Flow 3 Short Grass Pasture Kv= 7.0 fps

Summary for Subcatchment 102BS: P-DA-2B Runoff

=

2.66 cfs @ 12.15 hrs, Volume=

0.229 af, Depth> 2.03"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 25-YR NRCC Rainfall=6.05" Area (ac) 0.106 1.138 0.106 1.350 1.350

CN 55 58 96 61

Description Woods, Good, HSG B Meadow, non-grazed, HSG B Gravel surface, HSG B Weighted Average 100.00% Pervious Area

2836.00 Post-Development

Type III 24-hr 25-YR NRCC Rainfall=6.05"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Tc Length Slope (min) (feet) (ft/ft) 6.4 50 0.0144 3.4

172

0.1 9.9

Velocity (ft/sec) 0.13

0.0144

0.84

15 0.2000

3.13

237

Capacity (cfs)

Printed 4/26/2017 Page 21

Description Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Short Grass Pasture Kv= 7.0 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Short Grass Pasture Kv= 7.0 fps

Total

Summary for Subcatchment 103AS: P-DA-3A Runoff

=

0.43 cfs @ 12.17 hrs, Volume=

0.068 af, Depth> 0.63"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 25-YR NRCC Rainfall=6.05" Area (ac) 0.022 0.013 0.670 0.068 0.198 0.020 0.044 0.021 0.236 1.292 1.257 0.035

CN 98 98 30 55 77 39 61 80 30 42

Tc Length (min) (feet) 6.0

Description Paved parking, HSG A Paved parking, HSG D Woods, Good, HSG A Woods, Good, HSG B Woods, Good, HSG D >75% Grass cover, Good, HSG A >75% Grass cover, Good, HSG B >75% Grass cover, Good, HSG D Meadow, non-grazed, HSG A Weighted Average 97.29% Pervious Area 2.71% Impervious Area Slope (ft/ft)

Velocity (ft/sec)

Capacity (cfs)

Description Direct Entry, Minimum

Summary for Subcatchment 103BS: P-DA-3B Runoff

=

7.58 cfs @ 12.26 hrs, Volume=

0.844 af, Depth> 1.46"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 25-YR NRCC Rainfall=6.05"

2836.00 Post-Development

Type III 24-hr 25-YR NRCC Rainfall=6.05"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Area (ac) 0.056 0.252 0.072 0.217 1.924 0.054 0.982 1.191 2.037 0.143 6.928 6.548 0.380 0.072

CN 98 98 98 30 55 39 61 30 58 96 55

Adj

54

Tc Length Slope (min) (feet) (ft/ft) 9.8 50 0.0050

Description Paved parking, HSG A Paved parking, HSG B Unconnected roofs, HSG B Woods, Good, HSG A Woods, Good, HSG B >75% Grass cover, Good, HSG A >75% Grass cover, Good, HSG B Meadow, non-grazed, HSG A Meadow, non-grazed, HSG B Gravel surface, HSG B Weighted Average, UI Adjusted 94.52% Pervious Area 5.48% Impervious Area 18.95% Unconnected Velocity (ft/sec) 0.09

4.3

347

0.0363

1.33

1.8

192

0.0625

1.75

31 0.0955

2.16

0.2 16.1

620

Printed 4/26/2017 Page 22

Capacity (cfs)

Description Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Short Grass Pasture Kv= 7.0 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Short Grass Pasture Kv= 7.0 fps Shallow Concentrated Flow, Shallow Concentrated Flow 3 Short Grass Pasture Kv= 7.0 fps

Total

Summary for Reach 110R: P-DP-1 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = Inflow = Outflow =

10.114 ac, 0.08% Impervious, Inflow Depth > 0.18" for 25-YR NRCC event 0.26 cfs @ 17.39 hrs, Volume= 0.153 af 0.26 cfs @ 17.39 hrs, Volume= 0.153 af, Atten= 0%, Lag= 0.0 min

Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs

Summary for Reach 120R: P-DP-2 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = Inflow = Outflow =

5.248 ac, 4.10% Impervious, Inflow Depth > 1.25" for 25-YR NRCC event 4.10 cfs @ 12.19 hrs, Volume= 0.547 af 4.10 cfs @ 12.19 hrs, Volume= 0.547 af, Atten= 0%, Lag= 0.0 min

Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs

2836.00 Post-Development

Type III 24-hr 25-YR NRCC Rainfall=6.05"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Printed 4/26/2017 Page 23

Summary for Reach 130R: P-DP-3 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = Inflow = Outflow =

8.220 ac, 5.05% Impervious, Inflow Depth > 1.23" for 25-YR NRCC event 5.19 cfs @ 12.51 hrs, Volume= 0.842 af 5.19 cfs @ 12.51 hrs, Volume= 0.842 af, Atten= 0%, Lag= 0.0 min

Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs

Summary for Pond 101AP: BASIN-1 Inflow Area = Inflow = Outflow = Primary =

8.231 ac, 0.86 cfs @ 0.24 cfs @ 0.24 cfs @

0.10% Impervious, Inflow Depth > 0.40" for 25-YR NRCC event 12.75 hrs, Volume= 0.274 af 17.44 hrs, Volume= 0.140 af, Atten= 72%, Lag= 281.9 min 17.44 hrs, Volume= 0.140 af

Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 494.01' @ 17.44 hrs Surf.Area= 8,808 sf Storage= 6,364 cf Plug-Flow detention time= 332.1 min calculated for 0.140 af (51% of inflow) Center-of-Mass det. time= 176.5 min ( 1,159.5 - 983.0 ) Volume #1

Invert 493.00'

Elevation (feet) 493.00 494.00 496.00 Device #1

Avail.Storage 30,824 cf

Surf.Area (sq-ft) 3,844 8,790 15,717

Routing Primary

Invert 495.00'

#2

Primary

494.00'

#3

Primary

493.75'

Storage Description Custom Stage Data (Prismatic)Listed below (Recalc)

Inc.Store (cubic-feet) 0 6,317 24,507

Cum.Store (cubic-feet) 0 6,317 30,824

Outlet Devices 20.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 12.0" Round Culvert L= 30.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 494.00' / 493.00' S= 0.0333 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf 12.0" Round Culvert L= 30.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 493.75' / 493.00' S= 0.0250 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf

Primary OutFlow Max=0.24 cfs @ 17.44 hrs HW=494.01' (Free Discharge) 1=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) 2=Culvert (Inlet Controls 0.00 cfs @ 0.22 fps) 3=Culvert (Inlet Controls 0.24 cfs @ 1.52 fps)

2836.00 Post-Development

Type III 24-hr 25-YR NRCC Rainfall=6.05"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Printed 4/26/2017 Page 24

Summary for Pond 102P: BASIN-2 Inflow Area = Inflow = Outflow = Primary =

1.350 ac, 2.66 cfs @ 0.17 cfs @ 0.17 cfs @

0.00% Impervious, Inflow Depth > 2.03" for 25-YR NRCC event 12.15 hrs, Volume= 0.229 af 15.45 hrs, Volume= 0.121 af, Atten= 93%, Lag= 198.0 min 15.45 hrs, Volume= 0.121 af

Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 526.52' @ 15.45 hrs Surf.Area= 12,279 sf Storage= 5,914 cf Plug-Flow detention time= 326.6 min calculated for 0.120 af (53% of inflow) Center-of-Mass det. time= 201.0 min ( 1,063.0 - 862.0 ) Volume #1

Invert 526.00'

Elevation (feet) 526.00 528.00 Device #1 #2

Avail.Storage 28,174 cf

Surf.Area (sq-ft) 10,288 17,886

Storage Description Basin (Prismatic) Listed below (Recalc)

Inc.Store (cubic-feet) 0 28,174

Routing Primary

Invert 527.00'

Primary

526.25'

Cum.Store (cubic-feet) 0 28,174

Outlet Devices 20.0' long x 10.0' breadth Riprap Overflow Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 6.0" Round Culvert L= 60.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 526.25' / 525.00' S= 0.0208 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.20 sf

Primary OutFlow Max=0.17 cfs @ 15.45 hrs HW=526.52' (Free Discharge) 1=Riprap Overflow Weir ( Controls 0.00 cfs) 2=Culvert (Inlet Controls 0.17 cfs @ 1.57 fps)

Summary for Pond 103P: BASIN-3 Inflow Area = Inflow = Outflow = Primary =

6.928 ac, 7.58 cfs @ 4.93 cfs @ 4.93 cfs @

5.48% Impervious, Inflow Depth > 1.46" for 25-YR NRCC event 12.26 hrs, Volume= 0.844 af 12.53 hrs, Volume= 0.774 af, Atten= 35%, Lag= 16.1 min 12.53 hrs, Volume= 0.774 af

Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 502.14' @ 12.53 hrs Surf.Area= 8,206 sf Storage= 7,303 cf Plug-Flow detention time= 69.8 min calculated for 0.772 af (91% of inflow) Center-of-Mass det. time= 29.5 min ( 915.9 - 886.4 )

2836.00 Post-Development

Type III 24-hr 25-YR NRCC Rainfall=6.05"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Volume #1

Invert 501.00'

Elevation (feet) 501.00 502.00 504.00 Device #1

Avail.Storage 28,347 cf

Surf.Area (sq-ft) 4,660 7,748 14,395

Routing Primary

Invert 503.00'

#2

Primary

501.42'

#3

Primary

501.42'

Printed 4/26/2017 Page 25

Storage Description Custom Stage Data (Prismatic)Listed below (Recalc)

Inc.Store (cubic-feet) 0 6,204 22,143

Cum.Store (cubic-feet) 0 6,204 28,347

Outlet Devices 20.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 12.0" Round Culvert X 2.00 L= 35.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 501.42' / 500.00' S= 0.0406 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf 15.0" Round Culvert L= 35.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 501.42' / 500.00' S= 0.0406 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 1.23 sf

Primary OutFlow Max=4.91 cfs @ 12.53 hrs HW=502.14' (Free Discharge) 1=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) 2=Culvert (Inlet Controls 3.06 cfs @ 2.54 fps) 3=Culvert (Inlet Controls 1.85 cfs @ 2.54 fps)

2836.00 Post-Development

Type III 24-hr 100-YR NRCC Rainfall=8.59"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Printed 4/26/2017 Page 26

Summary for Subcatchment 101AS: P-DA-1A Runoff

=

0.38 cfs @ 12.37 hrs, Volume=

0.088 af, Depth> 0.56"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100-YR NRCC Rainfall=8.59" Area (ac) 1.479 0.001 0.403 1.883 1.883

CN 30 77 30 30

Tc Length (min) (feet) 6.0

Description Woods, Good, HSG A Woods, Good, HSG D Meadow, non-grazed, HSG A Weighted Average 100.00% Pervious Area Slope (ft/ft)

Velocity (ft/sec)

Capacity (cfs)

Description Direct Entry, Minimum

Summary for Subcatchment 101BS: P-DA-1B Runoff

=

5.05 cfs @ 12.57 hrs, Volume=

0.889 af, Depth> 1.30"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100-YR NRCC Rainfall=8.59" Area (ac) 0.452 2.021 5.336 0.363 0.008 0.051 8.231 8.223 0.008 0.008

CN 30 55 30 58 98 96 38

Description Woods, Good, HSG A Woods, Good, HSG B Meadow, non-grazed, HSG A Meadow, non-grazed, HSG B Unconnected pavement, HSG B Gravel surface, HSG B Weighted Average 99.90% Pervious Area 0.10% Impervious Area 100.00% Unconnected

Tc Length Slope (min) (feet) (ft/ft) 13.0 50 0.0690

Velocity (ft/sec) 0.06

12.8

292

0.0231

0.38

5.4

260

0.1045

0.81

31.2

602

Total

Capacity (cfs)

Description Sheet Flow, Sheet Flow Woods: Dense underbrush n= 0.800 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Forest w/Heavy Litter Kv= 2.5 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Forest w/Heavy Litter Kv= 2.5 fps

2836.00 Post-Development

Type III 24-hr 100-YR NRCC Rainfall=8.59"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Printed 4/26/2017 Page 27

Summary for Subcatchment 102AS: P-DA-2A Runoff

=

10.17 cfs @ 12.17 hrs, Volume=

0.922 af, Depth> 2.84"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100-YR NRCC Rainfall=8.59" Area (ac) 0.105 0.053 0.057 1.156 0.773 0.117 1.205 0.432 3.898 3.683 0.215 0.162

CN 98 98 98 30 55 77 61 58 53

Adj

52

Tc Length Slope (min) (feet) (ft/ft) 3.8 50 0.0514

Description Unconnected pavement, HSG B Water Surface, HSG B Unconnected roofs, HSG B Woods, Good, HSG A Woods, Good, HSG B Woods, Good, HSG D >75% Grass cover, Good, HSG B Meadow, non-grazed, HSG B Weighted Average, UI Adjusted 94.48% Pervious Area 5.52% Impervious Area 75.35% Unconnected Velocity (ft/sec) 0.22

4.3

208

0.0133

0.81

1.3

168

0.0954

2.16

2.2

121

0.0165

0.90

11.6

547

Total

Capacity (cfs)

Description Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Short Grass Pasture Kv= 7.0 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Short Grass Pasture Kv= 7.0 fps Shallow Concentrated Flow, Shallow Concentrated Flow 3 Short Grass Pasture Kv= 7.0 fps

Summary for Subcatchment 102BS: P-DA-2B Runoff

=

5.30 cfs @ 12.15 hrs, Volume=

0.438 af, Depth> 3.89"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100-YR NRCC Rainfall=8.59" Area (ac) 0.106 1.138 0.106 1.350 1.350

CN 55 58 96 61

Description Woods, Good, HSG B Meadow, non-grazed, HSG B Gravel surface, HSG B Weighted Average 100.00% Pervious Area

2836.00 Post-Development

Type III 24-hr 100-YR NRCC Rainfall=8.59"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Tc Length Slope (min) (feet) (ft/ft) 6.4 50 0.0144 3.4

172

0.1 9.9

Velocity (ft/sec) 0.13

0.0144

0.84

15 0.2000

3.13

237

Capacity (cfs)

Printed 4/26/2017 Page 28

Description Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Short Grass Pasture Kv= 7.0 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Short Grass Pasture Kv= 7.0 fps

Total

Summary for Subcatchment 103AS: P-DA-3A Runoff

=

2.10 cfs @ 12.11 hrs, Volume=

0.186 af, Depth> 1.73"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100-YR NRCC Rainfall=8.59" Area (ac) 0.022 0.013 0.670 0.068 0.198 0.020 0.044 0.021 0.236 1.292 1.257 0.035

CN 98 98 30 55 77 39 61 80 30 42

Tc Length (min) (feet) 6.0

Description Paved parking, HSG A Paved parking, HSG D Woods, Good, HSG A Woods, Good, HSG B Woods, Good, HSG D >75% Grass cover, Good, HSG A >75% Grass cover, Good, HSG B >75% Grass cover, Good, HSG D Meadow, non-grazed, HSG A Weighted Average 97.29% Pervious Area 2.71% Impervious Area Slope (ft/ft)

Velocity (ft/sec)

Capacity (cfs)

Description Direct Entry, Minimum

Summary for Subcatchment 103BS: P-DA-3B Runoff

=

17.53 cfs @ 12.24 hrs, Volume=

1.771 af, Depth> 3.07"

Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100-YR NRCC Rainfall=8.59"

2836.00 Post-Development

Type III 24-hr 100-YR NRCC Rainfall=8.59"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Area (ac) 0.056 0.252 0.072 0.217 1.924 0.054 0.982 1.191 2.037 0.143 6.928 6.548 0.380 0.072

CN 98 98 98 30 55 39 61 30 58 96 55

Adj

54

Tc Length Slope (min) (feet) (ft/ft) 9.8 50 0.0050

Description Paved parking, HSG A Paved parking, HSG B Unconnected roofs, HSG B Woods, Good, HSG A Woods, Good, HSG B >75% Grass cover, Good, HSG A >75% Grass cover, Good, HSG B Meadow, non-grazed, HSG A Meadow, non-grazed, HSG B Gravel surface, HSG B Weighted Average, UI Adjusted 94.52% Pervious Area 5.48% Impervious Area 18.95% Unconnected Velocity (ft/sec) 0.09

4.3

347

0.0363

1.33

1.8

192

0.0625

1.75

31 0.0955

2.16

0.2 16.1

620

Printed 4/26/2017 Page 29

Capacity (cfs)

Description Sheet Flow, Sheet Flow Grass: Short n= 0.150 P2= 3.23" Shallow Concentrated Flow, Shallow Concentrated Flow 1 Short Grass Pasture Kv= 7.0 fps Shallow Concentrated Flow, Shallow Concentrated Flow 2 Short Grass Pasture Kv= 7.0 fps Shallow Concentrated Flow, Shallow Concentrated Flow 3 Short Grass Pasture Kv= 7.0 fps

Total

Summary for Reach 110R: P-DP-1 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = Inflow = Outflow =

10.114 ac, 0.08% Impervious, Inflow Depth > 0.98" for 100-YR NRCC event 2.24 cfs @ 13.27 hrs, Volume= 0.825 af 2.24 cfs @ 13.27 hrs, Volume= 0.825 af, Atten= 0%, Lag= 0.0 min

Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs

Summary for Reach 120R: P-DP-2 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = Inflow = Outflow =

5.248 ac, 4.10% Impervious, Inflow Depth > 2.82" for 100-YR NRCC event 10.19 cfs @ 12.18 hrs, Volume= 1.235 af 10.19 cfs @ 12.18 hrs, Volume= 1.235 af, Atten= 0%, Lag= 0.0 min

Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs

2836.00 Post-Development

Type III 24-hr 100-YR NRCC Rainfall=8.59"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Printed 4/26/2017 Page 30

Summary for Reach 130R: P-DP-3 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = Inflow = Outflow =

8.220 ac, 5.05% Impervious, Inflow Depth > 2.74" for 100-YR NRCC event 12.24 cfs @ 12.43 hrs, Volume= 1.880 af 12.24 cfs @ 12.43 hrs, Volume= 1.880 af, Atten= 0%, Lag= 0.0 min

Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs

Summary for Pond 101AP: BASIN-1 Inflow Area = Inflow = Outflow = Primary =

8.231 ac, 5.05 cfs @ 2.07 cfs @ 2.07 cfs @

0.10% Impervious, Inflow Depth > 1.30" for 100-YR NRCC event 12.57 hrs, Volume= 0.889 af 13.27 hrs, Volume= 0.736 af, Atten= 59%, Lag= 42.5 min 13.27 hrs, Volume= 0.736 af

Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 494.43' @ 13.27 hrs Surf.Area= 10,296 sf Storage= 10,466 cf Plug-Flow detention time= 134.8 min calculated for 0.735 af (83% of inflow) Center-of-Mass det. time= 63.0 min ( 988.8 - 925.8 ) Volume #1

Invert 493.00'

Elevation (feet) 493.00 494.00 496.00 Device #1

Avail.Storage 30,824 cf

Surf.Area (sq-ft) 3,844 8,790 15,717

Routing Primary

Invert 495.00'

#2

Primary

494.00'

#3

Primary

493.75'

Storage Description Custom Stage Data (Prismatic)Listed below (Recalc)

Inc.Store (cubic-feet) 0 6,317 24,507

Cum.Store (cubic-feet) 0 6,317 30,824

Outlet Devices 20.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 12.0" Round Culvert L= 30.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 494.00' / 493.00' S= 0.0333 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf 12.0" Round Culvert L= 30.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 493.75' / 493.00' S= 0.0250 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf

Primary OutFlow Max=2.07 cfs @ 13.27 hrs HW=494.43' (Free Discharge) 1=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) 2=Culvert (Inlet Controls 0.65 cfs @ 1.98 fps) 3=Culvert (Inlet Controls 1.42 cfs @ 2.49 fps)

2836.00 Post-Development

Type III 24-hr 100-YR NRCC Rainfall=8.59"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Printed 4/26/2017 Page 31

Summary for Pond 102P: BASIN-2 Inflow Area = Inflow = Outflow = Primary =

1.350 ac, 5.30 cfs @ 0.49 cfs @ 0.49 cfs @

0.00% Impervious, Inflow Depth > 3.89" for 100-YR NRCC event 12.15 hrs, Volume= 0.438 af 13.76 hrs, Volume= 0.313 af, Atten= 91%, Lag= 96.7 min 13.76 hrs, Volume= 0.313 af

Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 526.84' @ 13.76 hrs Surf.Area= 13,478 sf Storage= 9,976 cf Plug-Flow detention time= 264.8 min calculated for 0.313 af (71% of inflow) Center-of-Mass det. time= 168.8 min ( 1,011.6 - 842.8 ) Volume #1

Invert 526.00'

Elevation (feet) 526.00 528.00 Device #1 #2

Avail.Storage 28,174 cf

Surf.Area (sq-ft) 10,288 17,886

Storage Description Basin (Prismatic) Listed below (Recalc)

Inc.Store (cubic-feet) 0 28,174

Routing Primary

Invert 527.00'

Primary

526.25'

Cum.Store (cubic-feet) 0 28,174

Outlet Devices 20.0' long x 10.0' breadth Riprap Overflow Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 6.0" Round Culvert L= 60.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 526.25' / 525.00' S= 0.0208 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.20 sf

Primary OutFlow Max=0.49 cfs @ 13.76 hrs HW=526.84' (Free Discharge) 1=Riprap Overflow Weir ( Controls 0.00 cfs) 2=Culvert (Inlet Controls 0.49 cfs @ 2.48 fps)

Summary for Pond 103P: BASIN-3 Inflow Area = Inflow = Outflow = Primary =

6.928 ac, 17.53 cfs @ 11.36 cfs @ 11.36 cfs @

5.48% Impervious, Inflow Depth > 3.07" for 100-YR NRCC event 12.24 hrs, Volume= 1.771 af 12.48 hrs, Volume= 1.694 af, Atten= 35%, Lag= 14.4 min 12.48 hrs, Volume= 1.694 af

Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 502.89' @ 12.48 hrs Surf.Area= 10,704 sf Storage= 14,409 cf Plug-Flow detention time= 43.8 min calculated for 1.694 af (96% of inflow) Center-of-Mass det. time= 20.8 min ( 883.8 - 863.0 )

2836.00 Post-Development

Type III 24-hr 100-YR NRCC Rainfall=8.59"

283600HC001A Prepared by Microsoft

HydroCAD® 10.00-15 s/n 04493 © 2015 HydroCAD Software Solutions LLC

Volume #1

Invert 501.00'

Elevation (feet) 501.00 502.00 504.00 Device #1

Avail.Storage 28,347 cf

Surf.Area (sq-ft) 4,660 7,748 14,395

Routing Primary

Invert 503.00'

#2

Primary

501.42'

#3

Primary

501.42'

Printed 4/26/2017 Page 32

Storage Description Custom Stage Data (Prismatic)Listed below (Recalc)

Inc.Store (cubic-feet) 0 6,204 22,143

Cum.Store (cubic-feet) 0 6,204 28,347

Outlet Devices 20.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 12.0" Round Culvert X 2.00 L= 35.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 501.42' / 500.00' S= 0.0406 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf 15.0" Round Culvert L= 35.0' CPP, mitered to conform to fill, Ke= 0.700 Inlet / Outlet Invert= 501.42' / 500.00' S= 0.0406 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 1.23 sf

Primary OutFlow Max=11.35 cfs @ 12.48 hrs HW=502.89' (Free Discharge) 1=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) 2=Culvert (Inlet Controls 6.56 cfs @ 4.18 fps) 3=Culvert (Inlet Controls 4.78 cfs @ 3.90 fps)

Appendix D Drawdown & Riprap-Sizing Calculation

BEALS+THOMAS Standard 3: Drawdown

Rv (K) (Bottom Area)

Drawdown Time =

where:

Rv = Storage Volume Below Outlet [Ac-ft] K= Infiltration Rate [in/hr] Bottom Area= Bottom Area of Recharge System [Ac]

Basin 1 Rv =

0.107 Ac-ft

K=

0.270 in/hr

Bottom Area =

0.088 Acres

Drawdown Time =

53.856 Hours

(Mapped as HSG "A" & "B"; Rawls Rate for HSG "C" Soils) < 72 Hours, Design is in compliance with the standard.

Basin 2 Rv =

0.075 Ac-ft

K=

0.270 in/hr

Bottom Area =

0.236 Acres

Drawdown Time =

14.070 Hours

(Mapped as HSG "A" & "B"; Rawls Rate for HSG "C" Soils) < 72 Hours, Design is in compliance with the standard.

Basin 3 Rv =

0.062 Ac-ft

K=

0.270 in/hr

Bottom Area =

0.107 Acres

Drawdown Time =

25.904 Hours

(Mapped as HSG "A" & "B"; Rawls Rate for HSG "C" Soils) < 72 Hours, Design is in compliance with the standard.

Note: 1. The infiltration BMPs have been designed to fully drain within 72 hours, therefore the proposed stormwater management design is in compliance with Standard 3 . 2. Infiltration Rate based on Volume 3, Chapter 1, Table 2.3.3 Rawls Rates from the 2008 MA DEP Stormwater Management Handbook. JOB NO. JOB:

283600SWM0001.xlsx

2836.00 CEC Solar #1206, LLC

COMPUTED BY: DATE:

TJM 08/09/17

CHECKED BY: DATE:

BEALS+THOMAS Riprap Apron Sizing

Median Stone Sizing: Where: D0 = Maximum Inside Pipe Diameter (ft) D50 = Median Riprap Diameter (ft) Q = Peak Discharge Rate from Hydraulic Design (cfs) TW = Tailwater Depth (ft); (Use 0.4D0 if TW is unknown, max 1.0Do) 2

g = Gravitational Acceleration Constant = 32.2 ft/s

Apron Sizing: D50 [In]

Apron Length (L) [ft}

Apron Depth [In]

Apron Width At Beginning

Apron Width At End

5 6 10 14 20 22

4D0 4D0 5D0 6D0 7D0 8D0

3.5D50 3.3D50 2.4D50 2.2D50 2.0D50 2.0D50

3D0 3D0 3D0 3D0 3D0 3D0

3D0 + ⅔L 3D0 + ⅔L 3D0 + ⅔L 3D0 + ⅔L 3D0 + ⅔L 3D0 + ⅔L

FLARED END SECTIONS

PIPE DIAMETER (D0) (FEET)

25-YEAR STORM FLOW (Q) (CFS)

12"@Basin #1 (2) 6"@Basin #2 (1) 12"@Basin #3 (2) 15" @Basin #3 (1)

1.00 0.50 1.00 1.25

0.24 0.17 3.06 1.85

MEDIAN STONE TAILWATER DIAMETER (TW) [ft] (D50) (INCHES) 0.4 0.2 0.4 0.5

5 5 5 5

APRON LENGTH (L) (FEET)

APRON DEPTH [In]

APRON WIDTH AT BEGINING (W1) [ft]

APRON WIDTH AT END (W2) [ft]

4.00 2.00 4.00 5.00

17.5 17.5 17.5 17.5

3.0 1.5 3.0 3.8

5.7 2.8 5.7 7.1

Notes [1] Calculations performed in accordance with Hydraulic Engineering Circular No. 14, Third Edition; Hydraulic Design of Energy Dissipaters for Culverts and Channels, dated July 2006. [2] Pipe shall extend 1 foot into riprap. [3] For maximum pipe size of 60". JOB NO. JOB:

2836 CEC Solar #1206

283600SWM0001.xlsx

COMPUTED BY: DATE:

TJM 08/14/17

CHECKED BY: DATE:

Appendix E Site Owner’s Manual

SITE OWNER’S MANUAL CEC Solar #1206, LLC 147 Lumber Street Hopkinton, Massachusetts

Prepared for: CEC Solar #1144, LLC c/o Clean Energy Collective 146 West Boylston Drive, 3rd Floor Worcester, MA 01606

Presented by:

BEALS+THOMAS BEALS AND THOMAS, INC. Reservoir Corporate Center 144 Turnpike Road Southborough, MA 01772-2104

August 10, 2017

283600P002

CEC Solar #1206, LLC Site Owner’s Manual Hopkinton, Massachusetts 283600RP002

TABLE OF CONTENTS 1.0

INTRODUCTION .......................................................................................................................................... 1-1

2.0

SITE OWNER’S AGREEMENT ................................................................................................................. 2-1

2.1 2.2 2.3 2.4 3.0

LONG-TERM POLLUTION PREVENTION PLAN ................................................................................ 3-1

3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 4.0

OPERATION AND MAINTENANCE COMPLIANCE STATEMENT........................................................................ 2-1 STORMWATER MAINTENANCE EASEMENTS ................................................................................................. 2-1 RECORD KEEPING ........................................................................................................................................ 2-1 TRAINING ..................................................................................................................................................... 2-2

STORAGE OF MATERIALS AND WASTE ......................................................................................................... 3-1 VEHICLE WASHING ...................................................................................................................................... 3-1 ROUTINE INSPECTIONS AND MAINTENANCE OF STORMWATER BMPS ......................................................... 3-1 SPILL PREVENTION AND RESPONSE .............................................................................................................. 3-1 VEGETATION MAINTENANCE PLAN.............................................................................................................. 3-1 STORAGE AND USE OF FERTILIZERS, HERBICIDES, AND PESTICIDES ............................................................ 3-2 SNOW REMOVAL PLAN ................................................................................................................................ 3-2 NUTRIENT MANAGEMENT PLAN .................................................................................................................. 3-2

LONG-TERM OPERATION AND MAINTENANCE PLAN ................................................................... 4-1

4.1 STORMWATER MANAGEMENT SYSTEM COMPONENTS ................................................................................. 4-1 4.2 INSPECTION AND MAINTENANCE SCHEDULES .............................................................................................. 4-1 4.2.1 Conveyance Swales ............................................................................................................................ 4-1 4.2.2 Infiltration Basins .............................................................................................................................. 4-2 4.2.3 Stormwater Outfalls ........................................................................................................................... 4-2 4.3 ESTIMATED OPERATION AND MAINTENANCE BUDGET ................................................................................ 4-3 4.4 PUBLIC SAFETY FEATURES .......................................................................................................................... 4-3

FIGURES FIGURE 1: SITE PLANS APPENDICES APPENDIX A: OPERATION AND MAINTENANCE LOG APPENDIX B: LIST OF EMERGENCY CONTACTS APPENDIX C: PROPRIETARY SEPARATOR TECHNICAL MANUAL

Table of Contents

i

CEC Solar #1206, LLC Site Owner’s Manual Hopkinton, Massachusetts 283600RP002

1.0

INTRODUCTION

The Site Owner’s Manual complies with the Long-Term Pollution Prevention Plan (Standard 4) and the Long-Term Operation and Maintenance Plan (Standard 9) requirements of the 2008 Massachusetts Department of Environmental Protection (DEP) Stormwater Handbook. The Manual outlines source control and pollution prevention measures and maintenance requirements of stormwater best management practices (BMPs) associated with the proposed development.

Introduction

1-1

CEC Solar #1206, LLC Site Owner’s Manual Hopkinton, Massachusetts 283600RP002

2.0

SITE OWNER’S AGREEMENT

2.1

Operation and Maintenance Compliance Statement Site Owner:

Clean Energy Collective 146 West Boylston Street, 3rd Floor Worcester, MA 01606

Responsible Party:

Clean Energy Collective

Clean Energy Collective or their successors shall maintain ownership of the on-site stormwater management system as well as the responsibility for operation and maintenance during the post-development stages of the project. The site has been inspected for erosion and appropriate measures have been taken to permanently stabilize any eroded areas. All aspects of stormwater best management practices (BMPs) have been inspected for damage, wear and malfunction, and appropriate steps have been taken to repair or replace the system or portions of the system so that the stormwater at the site may be managed in accordance with the Stormwater Management Standards. Future responsible parties shall be notified of their continuing legal responsibility to operate and maintain the BMPs. The operation and maintenance plan for the stormwater BMPs is being implemented. ___________________________ Responsible Party Signature

___________ Date

2.2

Stormwater Maintenance Easements There are no off-site areas utilized for stormwater control, therefore no stormwater management easements are required. The Site Owner will have access to all stormwater practices for inspection and maintenance, including direct maintenance access by heavy equipment to structures requiring regular maintenance.

2.3

Record Keeping The Site Owner shall maintain a rolling log in which all inspections and maintenance activities for the past three years shall be recorded. The Operation and Maintenance Log includes information pertaining to inspections, repairs, and disposal relevant to the project’s stormwater management system. The Log is located in Appendix A. The Operation and Maintenance Log shall be made available to the Conservation Commission and the DEP upon request. The Conservation Commission and the DEP shall be allowed to enter and inspect the premises to evaluate and ensure that the responsible party complies with the maintenance requirements for each BMP.

Site Owner’s Agreement

2-1

CEC Solar #1206, LLC Site Owner’s Manual Hopkinton, Massachusetts 283600RP002

2.4

Training Employees involved in grounds maintenance and emergency response will be educated on the general concepts of stormwater management and groundwater protection. The Site Owner’s Manual will be reviewed with the maintenance staff. The staff will be trained on the proper course of action for specific events expected to be incurred during routine maintenance or emergency situations.

Site Owner’s Agreement

2-2

CEC Solar #1206, LLC Site Owner’s Manual Hopkinton, Massachusetts 283600RP002

3.0

LONG-TERM POLLUTION PREVENTION PLAN

In compliance with Standard 4 of the 2008 DEP Stormwater Management Handbook, this section outlines source control and pollution prevention measures to be employed on-site after construction. 3.1

Storage of Materials and Waste The site shall be kept clear of trash and debris at all times. Certain materials and waste products shall be stored inside or outside upon an impervious surface and covered, as required by local and state regulations.

3.2

Vehicle Washing No commercial vehicle washing shall take place on site.

3.3

Routine Inspections and Maintenance of Stormwater BMPs See Section 4.0 Long-Term Operation and Maintenance Plan, for routine inspection and maintenance requirements for all proposed stormwater BMPs.

3.4

Spill Prevention and Response A contingency plan shall be implemented to address the spill or release of petroleum products and hazardous materials and will include the following measures: 1. Equipment necessary to quickly attend to inadvertent spills or leaks shall be stored on-site in a secure but accessible location. Such equipment shall include but not be limited to the following: safety goggles, chemically resistant gloves and overshoe boots, water and chemical fire extinguishers, sand and shovels, suitable absorbent materials, storage containers and first aid equipment (i.e. Indian Valley Industries, Inc. 55-gallon Spill Containment kit or approved equivalent). 2. Spills or leaks shall be treated properly according to material type, volume of spillage and location of spill. Mitigation shall include preventing further spillage, containing the spilled material in the smallest practical area, removing spilled material in a safe and environmentally-friendly manner, and remediation of any damage to the environment. 3. For large spills, Massachusetts DEP Hazardous Waste Incident Response Group shall be notified immediately at (617) 792-7653 and an emergency response contractor shall be consulted.

3.5

Vegetation Maintenance Plan See attached Solar Facility’s Operation and Maintenance Plan (Appendix C). Vegetated stormwater BMPs will be maintained as outlined in Section 4.0.

Long-Term Pollution Prevention Plan

3-1

CEC Solar #1206, LLC Site Owner’s Manual Hopkinton, Massachusetts 283600RP002

3.6

Storage and Use of Fertilizers, Herbicides, and Pesticides Fertilizers, herbicides, and pesticides will not be used at the proposed facility.

3.7

Snow Removal Plan See attached Solar Facility’s Operation and Maintenance Plan.

3.8

Nutrient Management Plan A nutrient management plan is required if a Total Maximum Daily Load (TMDL) has been developed that indicates that use of fertilizers containing nutrients or other specific pollutants must be reduced. The proposed project is located within the Upper/Middle Charles River watershed, which has a final TMDL issued for Phosphorous. As indicated in Section 3.6, fertilizers, herbicides, and pesticides will not be used at the proposed facility. Runoff generated onsite will be routed to infiltration basins for peak flow mitigation and treatment.

Long-Term Pollution Prevention Plan

3-2

CEC Solar #1206, LLC Site Owner’s Manual Hopkinton, Massachusetts 283600RP002

4.0

LONG-TERM OPERATION AND MAINTENANCE PLAN

This section outlines the stormwater best management practices (BMPs) associated with the proposed stormwater management system and identifies the long-term inspection and maintenance requirements for each BMP. 4.1

4.2

Stormwater Management System Components The following table outlines the type and quantity of the BMPs and their general location. Please reference the site plan(s) provided in the Figures section for exact location. All basins are accessible for maintenance from within the array. BMP Type

Quantity

Location

Conveyance Swale

1

Along eastern perimeter, to Basin 1.

Infiltration Basin

3

Basin 1 (northeastern corner of Site), Basin 2 (center of Site), & Basin 3 (western perimeter of Site)

Inspection and Maintenance Schedules 4.2.1

Conveyance Swales Conveyance swales shall be inspected and maintained as outlined below: •

• •

•

Swales shall be inspected during the first three months after installation to ensure vegetation is adequate and slopes are not eroding. All eroded areas shall be repaired and revegetated. Thereafter, swales shall be inspected once per year. During the inspection, swales shall be checked for: o Slope integrity o Soil moisture o Vegetative health o Soil stability o Soil compaction o Soil erosion o Ponding o Sedimentation Corrective measures shall be taken immediately as warranted by the inspections. The swales shall be mowed at least once per year. The vegetation shall be maintained at a length of 3-6 inches to ensure the effectiveness of the vegetation in reducing flow velocity and removing pollutants. Clippings shall be removed after each mowing. Sediment and debris shall be removed manually at least once per year.

Long-Term Operation and Maintenance Plan

4-1

CEC Solar #1206, LLC Site Owner’s Manual Hopkinton, Massachusetts 283600RP002

• •

4.2.2

If any evidence of hydrocarbons is found during inspection, the material shall be immediately removed using absorbent pads or other suitable measures and legally disposed. The swales shall be reseeded as necessary to maintain a dense growth of vegetation.

Infiltration Basins Infiltration basins shall be inspected and maintained after major storm events (rainfall totals greater than 2.5 inches in 24 hours) during the first three months of operation and twice a year and when there are discharges through the outlet control structure thereafter. Additionally, all pretreatment BMPs shall be inspected in accordance with the minimal requirements specified for those practices and after all major storm events. Inspections shall include the following measures: •

• • • •

During and after major storm events, the length of time standing water remains in the basin shall be recorded. o If the time is greater than 72 hours, thoroughly inspect the basin for signs of clogging. o A corrective action plan shall be developed by a qualified professional to restore infiltrative function. The Site Owner shall take immediate action to implement these corrective measures. Examine the outlet structure for evidence of clogging or outflow release velocities that are greater than the design velocity. Identify areas of sediment accumulation, differential settlement, cracking, and erosion within the basin. Inspect embankments for leakage and tree growth. Examine the health of the vegetation within the basin and on the embankments.

Corrective measures shall be taken immediately as warranted by the inspections. If any evidence of hydrocarbons is found during inspection, the material shall be immediately removed using absorbent pads or other suitable measures and legally disposed. Preventative maintenance shall include the following activities: • Mow the buffer area and basin bottom and side slopes, if vegetated. • Remove trash, debris, and accumulated organic matter. • Remove clippings after mowing. 4.2.3

Stormwater Outfalls Flared end sections and associated riprap spillways shall be inspected at least once per year and after major storm events (rainfall totals greater than 2.5

Long-Term Operation and Maintenance Plan

4-2

CEC Solar #1206, LLC Site Owner’s Manual Hopkinton, Massachusetts 283600RP002

inches in 24 hours) to ensure that the stability of the outlet area is maintained. The outfall area shall be kept clear of debris such as trash, branches, and sediment. Repairs shall be made immediately if riprap displacement or downstream channel scour is observed. 4.3

Estimated Operation and Maintenance Budget An operations and maintenance budget was prepared to approximate the annual cost of the inspections required in compliance with the DEP Stormwater Management Policy. The table below estimates the annual cost to inspect and maintain each proposed BMP, based on the requirements in Section 4.2. BMP Type Water Quality Swale Infiltration Basin Riprap Spillway Stormwater Outfalls

4.4

# of BMPS 1 3 3 6

Annual O&M Cost (per BMP) 1 $400-$800 $200 - $400 $50-$100 $50-$100 Total

Total Cost $400-$800 $600-$1,200 $150-$300 $300-$600

Public Safety Features The facility contains a perimeter fence and gates that will be locked to prevent unauthorized entry into the facility.

1

Annual maintenance cost is based on estimate of the cost to complete all inspection and maintenance measures outlined in Section 4.2. For BMPs that require sediment removal at regular intervals (i.e. every 5 or 10 years), the annual cost includes the annual percentage of that cost.

Long-Term Operation and Maintenance Plan

4-3

Figures Figure 1: Site Plans

Appendices

Appendix A Operation and Maintenance Log

CEC Solar #1206, LLC Operation and Maintenance Log Hopkinton, Massachusetts 283600RP002

OPERATION AND MAINTENANCE LOG This template is intended to comply with the operation and maintenance log requirements of the 2008 DEP Stormwater Management Handbook. Copies of this log should be made for all inspections and kept on file for three years from the inspection date. Name/Company of Inspector: Date/Time of Inspection: Weather Conditions: (Note current weather and any recent precipitation events)

Stormwater BMP

Inspection Observations

Actions Required

Appendix B List of Emergency Contacts

Emergency Contacts Massachusetts DEP Hazardous Waste Incident Response Group (617)792-7653 Town of Hopkinton Department of Public Works 66 Fruit Street Hopkinton, MA 01748 (508)497-9740 Town of Hopkinton Fire Department 73 Main Street Hopkinton, MA 01748 (508)497-2323 Town of Hopkinton Police Department 74 Main Street Hopkinton, MA 01748 (508)497-3401

Appendix F Stormwater Pollution Prevention Plan

283600RP003

August 10, 2017

BEALS AND THOMAS, INC. Reservoir Corporate Center 144 Turnpike Road Southborough, MA 01772-2104

BEALS+THOMAS

Prepared by:

T F A R D

CEC Solar #1206, LLC c/o Clean Energy Collective 146 West Boylston Drive, 3rd Floor Worcester, MA 01606

Prepared for:

147 Lumber Street Hopkinton, Massachusetts

CEC Solar #1206, LLC

EPA Construction General Permit

SITE EVALUATION, ASSESSMENT AND PLANNING ............................................4

OPERATOR(S)/ SUBCONTRACTORS ................................................................................... 1 STORMWATER TEAM........................................................................................................ 2

CONTACT INFORMATION/RESPONSIBLE PARTIES ...........................................1

EROSION AND SEDIMENT CONTROL BMPS ........................................................15

ENDANGERED SPECIES CERTIFICATION.......................................................................... 12 HISTORIC PRESERVATION .............................................................................................. 12 SAFE DRINKING WATER ACT UNDERGROUND INJECTION CONTROL REQUIREMENTS.... 13 APPLICABLE STATE OR LOCAL PROGRAMS .................................................................... 14

COMPLIANCE WITH APPLICABLE FEDERAL & STATE REQUIREMENTS 12

Table of Contents

i

4.1 NATURAL BUFFERS OR EQUIVALENT SEDIMENT CONTROLS .......................................... 15 4.2 MINIMIZE DISTURBED AREA AND PROTECT NATURAL FEATURES AND SOIL ................. 17 4.2.1 Preserve Existing Vegetation .................................................................................... 17 4.2.2 Stockpiling Topsoil.................................................................................................... 17 4.3 PHASED CONSTRUCTION ACTIVITY................................................................................ 17 4.3.1 Phase I ...................................................................................................................... 17

4.0

3.1 3.2 3.3 3.4

3.0

T F A R D

2.1 PROJECT/SITE INFORMATION ........................................................................................... 4 2.1.1 Emergency-Related Projects ....................................................................................... 5 2.2 NATURE AND SEQUENCE OF CONSTRUCTION ACTIVITY ................................................... 5 2.2.1 Function of the Construction Activity ......................................................................... 5 2.2.2 Building Demolition .................................................................................................... 5 2.2.3 Agricultural Land........................................................................................................ 5 2.2.4 Estimated Project Dates ............................................................................................. 5 2.3 SOILS, SLOPES, VEGETATION, AND CURRENT DRAINAGE PATTERNS ............................... 7 2.4 CONSTRUCTION SITE ESTIMATES ..................................................................................... 7 2.5 DISCHARGE INFORMATION............................................................................................... 8 2.5.1 Description of Receiving Storm Sewer Systems .......................................................... 8 2.5.2 Receiving Waters ........................................................................................................ 8 2.5.3 Impaired Waters/ TMDLs ........................................................................................... 8 2.5.4 Tier 2, 2.5, or 3 Waters ............................................................................................... 9 2.6 UNIQUE SITE FEATURES AND SENSITIVE AREAS .............................................................. 9 2.7 CONSTRUCTION SUPPORT ACTIVITIES.............................................................................. 9 2.7.1 Support Activity Site Information................................................................................ 9 2.7.2 Support Activity Contact Information ......................................................................... 9 2.8 POTENTIAL SOURCES OF POLLUTION ............................................................................... 9 2.8.1 Potential Sources of Sediment .................................................................................... 9 2.8.2 Potential Sources of Non-Sediment Pollutants ........................................................... 9 2.9 SITE PLANS .................................................................................................................... 11

2.0

1.1 1.2

1.0

TABLE OF CONTENTS

283600RP003

CEC Solar #1206, LLC Stormwater Pollution Prevention Plan (SWPPP) Hopkinton, Massachusetts

GOOD HOUSEKEEPING BMPS ..................................................................................23

6.0

Table of Contents

ii

POST-CONSTRUCTION BMPS ...................................................................................31

5.1 MATERIAL HANDLING AND WASTE MANAGEMENT ....................................................... 23 5.1.1 Solid or Construction Waste Disposal ...................................................................... 24 5.1.2 Recycling ................................................................................................................... 24 5.1.3 Sanitary and Septic Waste ........................................................................................ 25 5.1.4 Hazardous Materials and Waste............................................................................... 25 5.2 ESTABLISH PROPER BUILDING MATERIAL STAGING AREAS .......................................... 26 5.3 DESIGNATE WASHOUT AREAS ....................................................................................... 26 5.3.1 Concrete Washout ..................................................................................................... 26 5.3.2 Applicators, Containers and Paint Washout ............................................................ 27 5.4 ESTABLISH PROPER EQUIPMENT/VEHICLE FUELING AND MAINTENANCE PRACTICES ... 28 5.5 ALLOWABLE NON-STORMWATER DISCHARGES AND CONTROL EQUIPMENT / VEHICLE WASHING ................................................................................................................................... 28 5.6 SPILL PREVENTION AND CONTROL PROCEDURES ........................................................... 29 5.7 FERTILIZER DISCHARGE RESTRICTIONS ......................................................................... 29 5.8 ANY ADDITIONAL BMPS ............................................................................................... 30 5.9 ALLOWABLE NON-STORMWATER DISCHARGE MANAGEMENT ...................................... 30

5.0

T F A R D

INSPECTIONS AND MAINTENANCE .......................................................................34

PERMANENT SEEDING .................................................................................................... 32

FINAL STABILIZATION ..............................................................................................32

DETENTION BASIN ......................................................................................................... 31 INFILTRATION BASIN ..................................................................................................... 31 BIORETENTION AREA ..................................................................................................... 31 GRASS DRAINAGE CHANNELS........................................................................................ 31 INFILTRATION TRENCH .................................................................................................. 31 POROUS PAVERS ............................................................................................................ 31 TREE BOX FILTER .......................................................................................................... 31 DEEP SUMP AND HOODED CATCH BASINS AND WATER QUALITY STRUCTURES............ 31

T F A R D

RECORDKEEPING AND TRAINING .........................................................................36

10.1 10.2 10.3 10.4

10.0

Table of Contents

iii

SIGNATURE, PLAN REVIEW, AND MAKING PLANS AVAILABLE ...................................... 38 NOTICE OF PERMIT COVERAGE ........................................................................................ 38 OWNER CERTIFICATION ................................................................................................. 39 OPERATOR CERTIFICATION ............................................................................................ 40

CERTIFICATION AND NOTIFICATION ..................................................................38

9.1 RECORDKEEPING............................................................................................................ 36 9.2 LOG OF CHANGES TO THE SWPPP ................................................................................. 36 9.3 TRAINING ....................................................................................................................... 36 9.3.1 Individual(s) Responsible for Training ..................................................................... 36 9.3.2 Description of Training Conducted .......................................................................... 37

9.0

8.1 INSPECTIONS .................................................................................................................. 34 8.1.1 Inspection Schedule and Procedures ........................................................................ 34 8.2 REDUCTIONS IN INSPECTION FREQUENCY ...................................................................... 35 8.3 CORRECTIVE ACTION LOG ............................................................................................. 35

8.0

7.1

7.0

6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8

283600RP003

283600RP003

4.3.2 Phase II ..................................................................................................................... 17 4.4 CONTROL STORMWATER FLOWING ONTO AND THROUGH THE PROJECT........................ 17 4.4.1 Earth Dike ................................................................................................................. 17 4.4.2 Grass Drainage Channels......................................................................................... 17 4.5 STABILIZE SOIL .............................................................................................................. 18 4.5.1 Temporary Stabilization............................................................................................ 18 4.5.2 Mulching ................................................................................................................... 18 4.5.3 Permanent Stabilization ............................................................................................ 19 4.5.4 Dust Control ............................................................................................................. 19 4.6 PROTECT SLOPES ........................................................................................................... 19 4.6.1 Erosion Control Blanket ........................................................................................... 19 4.7 PROTECT STORM DRAIN INLETS .................................................................................... 19 4.7.1 Filter Bags ................................................................................................................ 19 4.8 ESTABLISH PERIMETER CONTROLS AND SEDIMENT BARRIERS ...................................... 20 4.8.1 Erosion Control Barrier ........................................................................................... 20 4.8.2 Silt Fence .................................................................................................................. 20 4.9 PREVENT SOIL COMPACTION ......................................................................................... 21 4.9.1 Protect Proposed Infiltration Areas.......................................................................... 21 4.10 RETAIN SEDIMENT ON-SITE ........................................................................................... 21 4.10.1 Temporary Sediment Basins ................................................................................. 21 4.11 ESTABLISH STABILIZED CONSTRUCTION ENTRANCE/EXIT............................................. 22 4.12 DEWATERING PRACTICES .............................................................................................. 22 4.13 ADDITIONAL BMPS ....................................................................................................... 23 4.13.1 BMP Name ............................................................................................................ 23

CEC Solar #1206, LLC Stormwater Pollution Prevention Plan (SWPPP) Hopkinton, Massachusetts

CEC Solar #1206, LLC Stormwater Pollution Prevention Plan (SWPPP) Hopkinton, Massachusetts

CONSTRUCTION GENERAL PERMIT

NOI AND ACKNOWLEDGEMENT LETTER FROM EPA

INSPECTION REPORTS

CORRECTIVE ACTION LOG

SWPPP AMENDMENT LOG

SUBCONTRACTOR CERTIFICATIONS/ AGREEMENTS

GRADING AND STABILIZATION ACTIVITIES LOG

TRAINING LOG

DELEGATION OF AUTHORITY

ENDANGARD SPECIES DOCUMENTATION

HISTORIC PRESERVATION DOCUMENTATION

TEMPORARY SEDIMENT BASIN SIZING CALCULATION

NATURAL BUFFER EQUIVALENCY CALCULATIONS

APPENDIX C:

APPENDIX D:

APPENDIX E:

APPENDIX F:

APPENDIX G:

APPENDIX H:

APPENDIX I:

APPENDIX J:

APPENDIX K:

APPENDIX L:

APPENDIX M:

APPENDIX N:

APPENDIX O:

Table of Contents

SITE PLANS

APPENDIX B:

T F A R D

GENERAL LOCATION MAP

APPENDIX A:

LIST OF APPENDICES

iv

283600RP003

CEC Solar #1206, LLC Stormwater Pollution Prevention Plan (SWPPP) Hopkinton, Massachusetts

Company:

Worcester

146 West Boylston Drive

TBD

MA

City:

TBD ZIP Code:

TBD

Name:

Telephone: TBD

TBD

Company:

24-Hour Emergency Contact

TBD

TBD

01606

Contact Information/Responsible Parties

Site Work Contractor

State:

Area of Control:

City:

Email: TBD

TBD

Address:

Email: TBD

TBD ZIP Code:

ZIP Code:

Telephone: TBD

TBD

TBD

Name:

Subcontractor Name

Company:

Subcontractor(s)

Telephone: TBD

TBD

TBD

Address:

State:

Email: TBD

State:

T F A R D TBD

Contractor Name

Name:

Company:

Telephone: TBD

City:

Address:

Name:

Clean Energy Collective

OPERATOR(S)/ SUBCONTRACTORS

1.1 Operator(s)

CONTACT INFORMATION/RESPONSIBLE PARTIES

1.0

1

1.2

Southborough

Address:

City:

MA

ZIP Code:

01772

Email: [email protected]

State:

TBD

TBD

TBD

City:

Telephone:

TBD

TBD

TBD

Company:

Name:

Address:

Inspection Personnel

TBD ZIP Code:

TBD

TBD

Contact Information/Responsible Parties

Email: TBD

State:

Email: TBD

TBD ZIP Code:

Telephone:

Address: State:

TBD

City:

TBD

TBD

Name:

TBD

Company:

T F A R D

2

Personnel Responsible for Installation & Maintenance of Stormwater BMPs

Telephone: 508-366-0560

Christopher Hale-Sills

144 Turnpike Road

Name:

Beals and Thomas, Inc.

Company:

SWPPP Preparer

STORMWATER TEAM

TBD TBD

Address: City: Telephone:

TBD ZIP Code: Email: TBD

State:

TBD

Contact Information/Responsible Parties

T F A R D

TBD TBD

Name:

TBD

Company:

Personnel Responsible for Taking Corrective Actions

3

Longitude:

-71.5308°

ZIP Code:

WGS 84 Unknown

01606

Yes

No

Site Evaluation, Assessment and Planning

NPDES project or permit tracking number: TBD

4

Are you applying for permit coverage as a “federal operator” as defined in Appendix A of the 2012 CGP? Yes No

Is this project considered a federal facility?

______________________________________________________

If yes, provide the name of the Indian tribe associated with the area of Indian country (including the name of Indian reservation if applicable), or if not in Indian country, provide the name of the Indian tribe associated with the property:

Is the project located on Indian country lands, or located on a property of religious of Yes No cultural significance to an Indian tribe?

Horizontal Reference Datum: NAD 27 NAD 83

T F A R D

Method for Determining Latitude/Longitude: USGS Topographic Map (specify scale: _________) EPA Website GPS Other (please specify): _Google Earth_______

42.2009°

Latitude:

MA

Middlesex

State:

County or Similar Subdivision:

Hopkinton

147 Lumber Street

Project Street/Location:

City:

CEC Solar #1206, LLC

PROJECT/SITE INFORMATION

2.1

Project/Site Name:

SITE EVALUATION, ASSESSMENT AND PLANNING

2.0

2.2

Yes

No

T F A R D

Yes

No

Site Evaluation, Assessment and Planning

Estimated Project Start Date: TBD Estimated Project Completion Date: TBD

2.2.4 Estimated Project Dates

2.2.3 Agricultural Land Was the pre-development land used for agriculture?

If yes, do any of the structures being demolished have at least 10,000 square feet Yes No of floor space?

2.2.2 Building Demolition Will there be demolition of any structure built or renovated before January 1, 1980? Yes No

Highway or Road Construction Other (please specify):_Solar Energy__

Institutional

Industrial

Multi-Family Residential

Utility

Commercial

Single-Family Residential

Function of the construction activity:

The project consists of the construction of a 6 MW solar energy facility within existing agricultural fields as well as in currently wooded areas.

2.2.1 Function of the Construction Activity

NATURE AND SEQUENCE OF CONSTRUCTION ACTIVITY

5

If yes, document the cause of the public emergency (e.g., natural disaster, extreme flooding conditions), information substantiating its occurrence (e.g., state disaster declaration), and a description of the construction necessary to reestablish effective public services:

Is this project in response to a public emergency?

2.1.1 Emergency-Related Projects

Construction Activity and BMP Descriptions

Before any site grading activities begin 1. Stake Limit of Construction. Workers shall be informed that no construction activity is to occur beyond this limit at any time. 2. Delineate the limit of the natural buffer to be maintained with flags, tape or other similar device. 3. Clear vegetation as necessary within the limits of construction. A stockpile of wood chips from tree cutting shall be left on site for stabilization. 4. Grub the areas where silt fence is required, removing stumps and roots as necessary. The existing ground surface shall be disturbed as little as possible prior to the start of construction. 5. Install silt fence and straw bales as shown on the plans. An adequate stockpile of erosion control materials shall be on site at all times for emergency or routine replacement and shall include materials to repair silt fences, straw bales, or any other devices planned for use during construction. 6. Construct stabilized construction exits. 7. Construct staging and materials storage area. 8. Install temporary sanitary facilities and dumpsters.

Date Start –Date End

Date Start –Date End

Site Evaluation, Assessment and Planning

6

Site grading 1. Begin site clearing and grubbing operations. 2. Commence excavation of stormwater management basins to act as temporary sedimentation basins during construction. 3. Commence construction of temporary drainage channels to direct runoff to sedimentation basin(s) during construction. Check dams shall be installed along the temporary drainage channels to reduce velocities and collect sediment. 4. Begin overall site grading and topsoil stripping. 5. Establish topsoil stockpile. 6. Install silt fences around stockpile and cover stockpiles. 7. Disturbed areas where construction will cease for more than 14 days shall be stabilized with erosion controls. Array Construction 1. Begin construction of Array. 2. Implement winter stabilization procedures.

T F A R D

Estimated Timeline of Activity Date Start –Date End

2.4

2.3

Final stabilization and landscaping 1. Convert temporary sediment basin(s) to (a) permanent infiltration basins. 2. Remove all temporary control BMPs and stabilize any areas disturbed by their removal with erosion controls 3. Prepare final seeding and landscaping. 4. Monitor stabilized areas until final stabilization is reached.

Total property area:

CONSTRUCTION SITE ESTIMATES

Site Evaluation, Assessment and Planning

TBD acres 7

Vegetation: The solar array is proposed within an area that is comprised of predominantly woodland vegetation. There is a portion of the property that is partially developed, and occupied by a single-family residence.

Drainage Patterns: The array is approximately centered on a high-point. Runoff from the site drains to the east and to the west. There are onsite bordering vegetated wetlands (BVW) at the eastern perimeter of the site as well as a potential vernal pool (PVP) and associated isolated vegetated wetland (IVW) at the southeastern quadrant. There is also a BVW at the western perimeter of the site (adjacent to Lumber Street). The resource areas at northeastern and western portions of the site ultimately flow to the north. The southeastern potion of the site (including the PVP and IVW) flows to the east and south.

Slopes: Slopes on site vary from 0% to 15%

T F A R D

Canton Fine Sandy Loam is a very deep, well drained soil on glaciated uplands. The typical soil profile is comprised of layers of fine sandy loam over gravelly fine sandy loam, over gravelly loamy sand. NRCS classifies these soils as Hydrologic Soil Group (HSG) “A” (extremely bouldery) & “B” (extremely stony). Narragansett Silt Loam, is a deep, well drained soil on glacial till plains and ground moraine. The typical soil profile is comprised of layers of silt loam over very gravelly loamy sand. NRCS classifies this soil as HSG “A”. Ridgebury Fine Sandy Loam, a very deep, poorly drained to somewhat poorly drained soil on glacial till uplands. The typical soil profile is comprised of layers of fine sandy loam over loamy fine sand, sand, and gravelly coarse sand. NRCS classifies this soil as HSG “D”.

Soil type(s): The Natural Resources Conservation Service (NRCS) Web Soil Survey lists the on-site soils as Canton Fine Sandy Loam, Narragansett Silt Loam, and some areas of Ridgebury Fine Sandy Loam.

SOILS, SLOPES, VEGETATION, AND CURRENT DRAINAGE PATTERNS

Date Start –Date End

2.5

TBD acres TBD % TBD TBD % TBD

Maximum area to be disturbed at one time:

Percentage impervious area before construction:

Runoff coefficient before construction:

Percentage impervious area after construction:

Runoff coefficient after construction:

2.8

Does your project/site discharge stormwater into a Municipal Separate Storm Sewer System (MS4)? Yes No

Yes

No

Yes

No

Site Evaluation, Assessment and Planning

List the pollutant(s) for which there is a TMDL: Phosphorus

8

If yes, list the title of the TMDL document: Total Maximum Daily Load for Nutrients in the Upper/Middle Charles River, Massachusetts

Has a TMDL been completed?

Describe the method(s) used to determine whether or not your project site discharges to an impaired water: Mass GIS Oliver mapping.

If yes, list the pollutant(s) causing the impairment: Phosphorus

Has the surface water been listed as “impaired?”

2.5.3 Impaired Waters/ TMDLs

Portions of the site drain to Echo Lake, which is a tier 2.5, or public water supply, which feeds the Charles River. Other portions of the site drain to Icehouse Pond, then Indian Brook, which feeds the Hopkinton Reservoir. A third portion of the site drains to Wildcat Pond, and then the Charles River.

2.5.2 Receiving Waters

2.7

2.6

2.5.1 Description of Receiving Storm Sewer Systems

T F A R D

DISCHARGE INFORMATION

TBD acres

Total construction site area to be disturbed:

Tier 2.5

Yes

Tier 3

No

T F A R D

Clearing and grubbing operations Grading and site excavation operations Vehicle tracking Topsoil stripping and stockpiling Landscaping operations

[2]

Fertilizer

Pesticides

Material/ Chemical

x

x

x

x

Chlorinated hydrocarbons, organophosphates, carbamates, arsenic Nitrogen, phosphorous

Various colored to colorless liquid, powder, pellets, or grains Liquid or solid grains

9

Herbicides used for noxious weed control Newly seeded areas

Location[1]

Site Evaluation, Assessment and Planning

Stormwater Pollutants

Physical Description

Combined Staging Area — small fueling activities, minor equipment maintenance, sanitary facilities, and hazardous waste storage. Materials Storage Area — general building materials, solvents, adhesives, paving materials, paints, aggregates, trash, and so on. Construction Activity — paving, curb/gutter installation, concrete pouring/mortar/stucco, and building construction Concrete Washout Area

2.8.2 Potential Sources of Non-Sediment Pollutants

x x x x x

2.8.1 Potential Sources of Sediment

POTENTIAL SOURCES OF POLLUTION

CONSTRUCTION SUPPORT ACTIVITIES Construction support activities are not required for the project.

There are onsite bordering vegetated wetlands (BVW) at the eastern perimeter of the site as well as a potential vernal pool (PVP) and associated isolated vegetated wetland (IVW) at the southeastern quadrant. There is also a BVW at the western perimeter of the site (adjacent to Lumber Street). The resource areas at northeastern and western portions of the site appear to ultimately flow to the north.

UNIQUE SITE FEATURES AND SENSITIVE AREAS

If yes specify which Tier the surface water is designated as: Tier 2

Is this surface water designated as a Tier 2, 2.5 or 3 water?

2.5.4 Tier 2, 2.5, or 3 Waters

Stoddard solvent, petroleum distillates, arsenic, copper, chromium

Naphtha

Metal oxides, stoddard solvent, talc, calcium carbonate, arsenic

Polymers, epoxies

Oil, petroleum distillates

Perchloroethylene, methylene chloride, trichloroethylene, petroleum distillates

Benzene, ethyl benzene, toluene, xylene, MTBE

Petroleum distillate, oil & grease, naphthalene, xylenes

Coal oil, petroleum distillates

Colorless, pale brown or pink petroleum hydrocarbon

Clear, blue-green to yellow liquid

Pale yellow liquid petroleum hydrocarbon

Gasoline

Diesel Fuel

Kerosene

Curb and gutter, walkways Timber pads and building construction Leaks or broken hoses from equipment Secondary containment/staging area Secondary containment/staging area Secondary containment/staging area Leaks or broken hoses from equipment

Building construction

Streets, parking areas, and roofing Building construction

No equipment cleaning allowed in project limits

Antifreeze/ coolant

Clear green/yellow liquid

Site Evaluation, Assessment and Planning

10

Ethylene glycol, propylene glycol, heavy metals (copper, lead, zinc) Sanitary Bacteria, parasites, and Various colored liquid Staging area toilets viruses [1] Area where material/chemical is used on-site. [2] Use of fertilizers containing nitrogen and/ or phosphorus in ratios greater than recommended by the manufacture must be documented.

Mineral oil

Brown oily petroleum hydrocarbon

Hydraulic oil/fluids

T F A R D

Clear amber or dark brown liquid

Various colored liquids

Paints

Wood preservatives

White or yellow liquid

Glue/ adhesives

Creamy white liquid

Black solid

Asphalt

Curing compounds

Colorless, blue, or yellow-green liquid

Cleaning solvents

2.9

T F A R D

See Appendix B: Site Plans

Site Evaluation, Assessment and Planning

Areas of federally-listed critical habitat for endangered or threatened species

11

Locations where polymers, flocculants, or other treatment chemicals will be used and stored

Locations of all pollutant-generating activities

Locations of storm drain inlets and stormwater control measures on the site and in the immediate vicinity of the site

Locations where stormwater discharges or allowable non-stormwater to surface water(s)

Boundary lines of any natural buffers,

Location of all waters of the U.S., including wetlands on or near the site. Indicate if water bodies are listed as impaired, or are identified as Tier 2, 2.5 or 3 waters.

Locations of off-site material, waste, borrow, or equipment storage areas

Locations [and timing] of stabilization measures

Location(s) of sediment, soil or other construction materials will be stockpiled

Locations of major structural and non-structural BMPs identified in the SWPPP

Natural features to be preserved

Direction(s) of stormwater flow and approximate slopes before and after major grading activities

Areas of soil disturbance and areas that will not be disturbed

Delineation of construction phasing, if applicable

These Site Plans include:

The Topographic Plan shows the undeveloped site and its current features. The Site Plans show the developed site.

SITE PLANS

3.2

ENDANGERED SPECIES CERTIFICATION

3.1

Compliance with Applicable Federal & State Requirements

If yes, provide documentation of the basis for your determination.

12

Step 3 If you answered no in Step 2, has it been determined that the installation of subsurface earth-disturbing stormwater controls will have no effect on historic properties? Yes No

Step 2 If you answered yes in Step 1, have prior surveys or evaluations conducted on the site already determined that historic properties do not exist, or that prior disturbances at the site have precluded the existence of historic properties? Yes No

Step 1 Will stormwater controls that require subsurface earth disturbance be installed on the site? Yes No

HISTORIC PRESERVATION

If yes, describe or refer to documentation that determines the likelihood of an impact on the identified species and/or habitat and the steps taken to address that impact.

If yes, describe the species and/or critical habitat:

T F A R D

Additionally, the NHESP Northern Long-eared Bat Locations in Massachusetts map, last updated March 24, 2016 was reviewed and it was determined that the Project does not occur within 0.25 miles of a known winter hibernacula or within a 150-foot radius of a known maternity roost tree. Therefore, no further review of potential impacts to Northern Long-eared Bat is required pursuant to the MESA.

Describe how this determination was made: The MASSGIS NHESP Priority Habitat of Rare Species Layer, Updated September, 2008, indicates that no priority habitat of rare species are located within the project site.

Are endangered or threatened species and critical habitats on or near the project area? Yes No

COMPLIANCE WITH APPLICABLE FEDERAL & STATE REQUIREMENTS

3.0

3.3

T F A R D

Compliance with Applicable Federal & State Requirements

13

If yes, attach documentation of contact between you and the applicable state agency or EPA Regional Office responsible for implementing the requirements for underground injection wells in the Safe Drinking Water Act and EPA’s implementing regulations at 40 CFR Parts 144-147.

Drywells, seepage pits, or improved sinkholes (if stormwater is directed to any bored, drilled, driven shaft or dug hole that is deeper than its widest surface dimension, or has a subsurface fluid distribution system)

Commercially manufactured pre-cast or pre-built proprietary subsurface detention vaults, chambers, or other devices designed to capture and infiltrate stormwater flow

Infiltration trenches (if stormwater is directed to any bored, drilled, driven shaft or dug hole that is deeper than its widest surface dimension, or has a subsurface fluid distribution system)

Do you plan to install any of the following controls?

SAFE DRINKING WATER ACT UNDERGROUND INJECTION CONTROL REQUIREMENTS

Other:

No agreement has been reached regarding measures to mitigate effects to historic properties from the installation of stormwater controls.

Written indication that adverse effects to historic properties from the installation of stormwater controls can be mitigated by agreed upon actions.

If no, no further documentation is required. If yes, describe the nature of their response and include documentation in the Appendix:

Step 4 If you answered no in Step 3, did the State Historic Preservation Officer (SHPO), Tribal Historic Preservation Office (THPO), or other tribal representative (whichever applies) respond within 15 calendar days to indicate whether the subsurface earth disturbances caused by the installation of stormwater controls affect historic properties? Yes No

3.4

Compliance with Applicable Federal & State Requirements

T F A R D

14

A plan to control construction-related impacts, including erosion, sedimentation, and other pollutant sources during construction and land disturbance activities (construction period erosion, sedimentation, and pollution prevention plans) shall be developed and implemented.

NATURAL BUFFERS OR EQUIVALENT SEDIMENT CONTROLS

Natural Buffers or Equivalent Sediment Controls Minimize disturbed area and protect natural features and soil Control stormwater flowing onto and through the project Stabilize soils Protect slopes Establish perimeter controls and sediment barriers Retain sediment on-site and control dewatering practices Establish stabilized construction exits

Good Housekeeping BMPs

15

It is infeasible to provide and maintain an undisturbed natural buffer of any size, therefore erosion and sediment controls will be implemented that achieve the sediment load reduction equivalent to a 50-foot undisturbed natural buffer. The estimated

Description of Controls: Provide a description of the additional erosion and sediment controls proposed, including the model or other tool used to estimate the sediment load reductions and the results from the calculation.

An undisturbed natural buffer of xx-feet will be provided along with supplemental erosion and sediment controls, which in combination achieves the sediment load reduction equivalent to a 50-foot undisturbed natural buffer. The estimated sediment removal calculations are included in the appendixes of this report and have been calculated using the applicable tables included in Appendix G of the 2012 Construction General Permit or site-specific calculations were performed to estimate the sediment removal of a 50-buffer zone and the efficiency of the reduced buffer zone and supplemental erosion control measures.

A 50-foot undisturbed natural buffer will be maintained. The 50-foot buffer is shown on the attached site plans and will be clearly marked off with flags, tape, or a similar marking device prior to the commencement of earth disturbing activities.

If yes, check the compliance alternative that applies:

Are there any surface waters located within 50 feet of your construction disturbances that receive stormwater discharges from the site? Yes No

4.1

x x x x x x x x

This SWPPP contains a listing of the erosion and sediment control best management practices (BMPs) that will be implemented to control pollutants in stormwater discharges. The BMPs are categorized under one of the areas of BMP activity as described below:

This SWPPP complies with the requirements of Standard 8 of the Massachusetts Department of Environmental Protection Stormwater Handbook, which states:

EROSION AND SEDIMENT CONTROL BMPS

4.0

APPLICABLE STATE OR LOCAL PROGRAMS

Good Housekeeping BMPs

16

Buffer disturbances will occur for the construction of a water-dependent structure or water access area (e.g., pier, boat ramp, and trail).

Buffer disturbances are authorized under a CWA Section 404 permit.

Alternative 2: A sediment discharge risk evaluation has been prepared and is included in the appendices of this report.

Alternative 1: A [select one: 50-foot buffer, a buffer <50 feet and > 30 has been provided with double perimeter controls buffer less than 30-feet has been provided with double perimeter controls with 7-day site stabilization requirements has been provided.] Provide a description on how the controls will comply with the CGP requirements.

The project qualifies as “small residential lot” construction, and complies with:

For a “linear project,” site constraints (e.g., limited right-of-way) make it infeasible for the site to meet any of the CGP Part 2.1.2.1.a compliance alternatives

No natural buffer exists due to preexisting development disturbances, such as impervious surfaces or structures that were constructed prior to the initiation of planning for this project.

There is no discharge of stormwater to surface waters through the area between the disturbed portions of the site and any surface waters located within 50 feet of the site. This includes situations where control measures have been implemented such as a berm or other barrier that will prevent such discharges.

T F A R D

The project qualifies for one of the exceptions in Part 2.1.2.1.e. of the 2012 Construction General Permit. Specifically:

Description: Include rationale for why a natural buffer cannot be maintained. Provide a description of the additional erosion and sediment controls proposed, including the model or other tool used to estimate the sediment load reductions and the results from the calculation. Include the estimated sediment removal rate from a natural 50-buffer and the proposed controls.

sediment removal calculations are included in the appendixes of this report and have been calculated using the applicable tables included in Appendix G of the 2012 Construction General Permit or site-specific calculations were performed to estimate the sediment removal of a 50-buffer zone and the efficiency of the reduced buffer zone and supplemental erosion control measures.

4.3

4.2

Design Specifications

Maintenance and Inspection:

Installation Schedule:

Description:

Good Housekeeping BMPs

17

A grass drainage channel shall be installed at location, as indicated on the site plans. The channel shall convey runoff to storm drain inlets and temporary sediment basins, as appropriate or at locations shown on plans. Some grass drainage channels shall remain as a permanent stormwater structure after construction is complete. The grass drainage channel shall be installed after clearing and grubbing operations are completed at the site. The channel shall be inspected weekly and immediately after storm events for erosion and structural failures. Before vegetation has been established in the channel, inspect erosion control blankets, embankments, and beds for erosion and accumulation of debris and sediment. Remove debris, sediment, and repair erosion control blankets, fiber rolls and embankments immediately.

4.3.1 Grass Drainage Channels

CONTROL STORMWATER FLOWING ONTO AND THROUGH THE PROJECT

Topsoil stripped from the immediate construction area shall be stockpiled as identified on the Site Plans and Sitework Specifications or as approved by the SWPPP preparer. Stockpiles shall be located outside of any natural buffers and away from any stormwater conveyances, drain inlets, and areas where stormwater flow is concentrated. Installation Topsoil stockpiles shall be established during grading activities. Schedule: The silt fence and temporary erosion controls shall be installed immediately after the stockpile has been established. For piles that will be unused for 14 or more days provide cover over the stockpile or temporary stabilization to avoid direct contract with precipitation and wind. Install a sediment barrier along all downgradient perimeter areas of stockpiles. Maintenance The area shall be inspected weekly for erosion and immediately after and storm events. Areas on or around the stockpile that have eroded shall Inspection: be stabilized immediately with erosion controls. See following Silt Fence section for Maintenance and inspection procedures.

Description:

4.2.1 Stockpiling Topsoil

MINIMIZE DISTURBED AREA AND PROTECT NATURAL FEATURES AND SOIL

4.4

Initiation of temporary vegetative cover shall occur immediately where construction will cease for more that 7 days. It shall be established using hydroseeding for areas of exposed soil (including stockpiles). Temporary stabilization measures shall be initiated immediately where construction activities will temporarily cease for more than 14 days. Stabilized areas shall be inspected weekly and after storm events until a dense cover of vegetation has become established. If failure is noticed at the seeded area, the area shall be reseeded, fertilized, and mulched immediately.

Maintenance and Inspection:

Good Housekeeping BMPs

18

Hydromulching shall provide immediate protection to exposed soils during short periods of disturbance. Hydromulch shall also be applied in areas that have been seeded for temporary or permanent stabilization. Hydromulch shall be applied to exposed soils during short periods of construction and seeded areas. Mulched areas shall be inspected weekly and after storm events to check for movement of mulch or erosion. If washout, breakage, or erosion occurs, the surface shall be repaired, and new mulch shall be applied to the damaged area.

T F A R D

Installation Schedule:

Description:

4.4.2 Mulching

Maintenance and Inspection:

Installation Schedule:

Description:

4.4.1 Temporary Stabilization

STABILIZE SOIL

1. The channel shall have a positive drainage to convey runoff to the storm drain inlets and temporary sediment basins.

Maintenance and Inspection:

Installation Schedule:

Description:

4.4.4 Dust Control

Initiation of permanent stabilization measures shall occur immediately after the final design grades are achieved and earth moving activities cease. Native species of plants shall be used to establish vegetative cover on exposed soils. Permanent stabilization shall be completed in accordance with the procedures outlined in the Final Stabilization section of this report. Portions of the site where construction activities have permanently ceased shall be stabilized, as soon as possible. All seeded areas shall be inspected weekly during construction activities and after storm events until a dense cover of vegetation has been established. If failure is noticed at the seeded area, the area shall be reseeded, fertilized, and mulched immediately. Care shall be taken to avoid compacting newly placed topsoil. After construction is completed at the site, permanently stabilized areas shall be monitored until final stabilization is reached.

Good Housekeeping BMPs

19

Dust from the site shall be controlled by using a mobile pressure-type distributor truck to apply water to disturbed areas. The mobile unit shall apply water at a rate of 300 gallons per acre and minimized as necessary to prevent runoff and ponding. Dust control shall be implemented as needed once site grading has been initiated and during windy conditions (forecasted or actual wind conditions of 20 mph or greater) while site grading is occurring. Spraying of water shall be performed no more than three times a day during the months of May–September and once per day during the months of October–April or whenever the dryness of the soil warrants it. At least one mobile unit shall be available at all times to distribute water to control dust on the project area. Each mobile unit shall be equipped with a positive shutoff valve to prevent over watering of the disturbed area.

T F A R D

Maintenance and Inspection:

Installation Schedule:

Description:

4.4.3 Permanent Stabilization

4.5

Good Housekeeping BMPs

20

Temporary Entrenched silt fence shall be installed to decrease the velocity of sheet flows and intercept and detain small amounts of sediment from disturbed areas. Installation Schedule: Silt fence shall be installed prior to clearing and grubbing. Maintenance and Silt fence shall be inspected weekly, following storms, and Inspection: daily during rainy periods. Damaged fencing shall be replaced. Concentrated flows shall be intercepted and rerouted. Sediment accumulations shall be removed when reaching a depth of 6-inches. Deteriorated fencing material shall be replaced. Used fencing shall be properly disposed of.

Permanent Description:

4.5.2 Silt Fence

T F A R D

Temporary An erosion control barrier, consisting of entrenched straw bales, straw wattles, compost socks and siltation fencing, shall be installed along the downgradient side of the proposed project to decrease the velocity of sheet flows and intercept and detain small amounts of sediment from disturbed areas. Installation Schedule: Erosion Control Barrier shall be installed prior to clearing and grubbing. Maintenance and Erosion Control Barrier shall be inspected weekly, Inspection: following storms, and daily during rainy periods. Damaged fencing shall be replaced. Concentrated flows shall be intercepted and rerouted. Sediment accumulations shall be removed when reaching a depth of 6-inches, or one-half of the above ground height of the barrier, whichever is less. Deteriorated fencing material shall be replaced. Used fencing shall be properly disposed of.

Permanent Description:

4.5.1 Erosion Control Barrier

ESTABLISH PERIMETER CONTROLS AND SEDIMENT BARRIERS

4.7

4.6

Good Housekeeping BMPs

21

Temporary Temporary sediment basins are located throughout the site between construction and wetland resource areas. These basins provide 3,600 cubic feet of storage per acre drained, as required by the EPA. Refer to the Temporary Sediment Basin Sizing Calculation located in Appendix K. Several temporary sediment basins will be utilized as sediment forebays following construction. Installation Schedule: Temporary Sediment Basins shall be installed during grading activities. Maintenance and Temporary Sediment Basins shall be inspected weekly and Inspection: following storms. Sediment shall be removed when it reaches a depth of one foot, or half the design capacity whichever is less. Damage to basin embankments and slopes shall be repaired.

Permanent Description:

4.7.1 Temporary Sediment Basins

RETAIN SEDIMENT ON-SITE

T F A R D

Temporary An erosion control barrier, consisting of entrenched straw bales and siltation fencing, shall be installed around the perimeter of all proposed infiltration areas to prevent construction vehicles from impacting the area, to decrease the velocity of sheet flows and intercept, and detain small amounts of sediment from disturbed areas. Installation Schedule: The erosion control barrier shall be installed after clearing and grubbing. Maintenance and Silt fence shall be inspected weekly, following storms, and Inspection: daily during rainy periods. Damaged fencing shall be replaced. Concentrated flows shall be intercepted and rerouted. Sediment accumulations shall be removed when reaching a depth of 6-inches. Deteriorated fencing material shall be replaced. Used fencing shall be properly disposed of.

Permanent Description:

4.6.1 Protect Proposed Infiltration Areas

PREVENT SOIL COMPACTION

4.9

4.8

Description:

DEWATERING PRACTICES

x x

Good Housekeeping BMPs

22

Visible floating solids or foam shall not be discharged; An oil-water separator or suitable filtration device (such as a cartridge filter) that is designed to remove oil, grease, or other products if dewatering water is found to contain these materials shall be used;

All groundwater or stormwater discharged from excavations, trenches, foundations, vaults, or other similar point shall be treated by sediment basins, sediment traps, sediment socks, dewatering tanks, tube settlers or filtration systems specifically designed to remove sediment from the excavations. All dewatering practices shall conform to the following:

T F A R D

Temporary Temporary gravel or crushed stone construction entrances/exits or other means shall be used to minimize off-site movement of soil with vehicles. Construction access points shall be maintained to minimize tracking of soil onto public roads and existing parking lots to remain. If the rock entrance is not working to keep streets clean, then install wheel wash, sweep streets, or wash streets if wash water can be collected. Installation Schedule: Stabilized construction entrance shall be installed prior to clearing and grubbing. Maintenance and Stabilized construction entrances shall be inspected daily. Inspection: Gravel or crushed stone shall be added if the pad is no longer in accordance with the specifications. If the rock entrance is not working to keep streets clean, then install wheel wash, sweep streets, or wash streets if wash water can be collected. When sediment has been tracked off of the site, it shall be removed by the end of the same working day, or by the end of the next working day if track-out occurs on a non work day. Remove sediment by sweeping, shoveling or vacuuming roadways were sediment has been tracked-out.

Permanent Description:

ESTABLISH STABILIZED CONSTRUCTION ENTRANCE/EXIT

GOOD HOUSEKEEPING BMPS

5.1

Material Handling and Waste Management Establish Proper Material Staging Areas Designate Washout Areas Establish Proper Equipment/Vehicle Fueling and Maintenance Practices Allowable Non-Stormwater Discharges and Control Equipment/Vehicle Washing Spill Prevention and Control Plan

Good Housekeeping BMPs

23

Several management procedures and practices are proposed to prevent and/or reduce the discharge of pollutants to stormwater from solid or liquid wastes that will be generated at the site. These measures are grouped into the following categories: (1) solid or construction waste disposal, (2) recycling, (3) sanitary and septic waste, and (4) hazardous materials.

MATERIAL HANDLING AND WASTE MANAGEMENT

x x x x x x

This SWPPP contains a listing of the good housekeeping best management practices (BMPs) that shall be implemented to control pollutants in stormwater discharges during construction-related work. The BMPs are categorized below:

5.0

Maintenance and Inspection:

Installation Schedule:

To the extent feasible, utilize vegetated, upland areas of the site to infiltrate dewatering water before discharge. In no case will surface waters be considered part of the treatment area; x Velocity dissipaters shall be installed at all points where dewatering activities are discharged to the surface. x With backwash water, either haul it away for disposal or return it to the beginning of the treatment process; and x Replace and clean the filter media used in dewatering devices when the pressure differential equals or exceeds the manufacturer’s specifications. Install settling or filtration methods prior to commencing dewatering. Engineer is required to provide or approve settling of filtration method design prior to installation. Settling of filtration controls shall be inspected weekly and following storms. Sediment shall be removed when it reaches a depth of one foot, or half the design capacity whichever is less.

x

Installation Schedule: Maintenance and Inspection:

Description:

5.1.2 Recycling

Good Housekeeping BMPs

24

Wood pallets, cardboard boxes, and other recyclable construction scraps shall be disposed of in a designated dumpster for recycling. The dumpster shall have a secure watertight lid, be placed away from stormwater conveyances and drains and meet all local and state solid-waste management regulations. Only solid recyclable construction scraps from the site shall be deposited in the dumpster. All personnel shall be instructed regarding the correct procedure for disposal of recyclable construction scraps. Notices that state these procedures shall be posted in the office trailer, and the individual who manages day-to-day site operations shall be responsible for seeing that these procedures are followed. Designated recycling dumpsters shall be installed once the area has been established. The recycling dumpster shall be inspected weekly and immediately after storm events. The recycling dumpster shall be emptied weekly and taken to an approved recycling center. If recyclable

T F A R D

All waste materials shall be collected and disposed of into metal trash dumpsters in the materials storage area. Dumpsters shall have a secure watertight lid, be placed away from stormwater conveyances and drains, and meet all federal, state, and municipal regulations. Only trash and construction debris from the site shall be deposited in the dumpster. No construction materials shall be buried on-site unless authorized by a program for recycling/beneficial use. All personnel shall be instructed regarding the correct disposal of trash and construction debris. Notices that state these practices shall be posted in the office trailer and the individual who manages daytoday site operations shall be responsible for seeing that these practices are followed. Installation Trash dumpsters shall be installed once the materials storage area Schedule: has been established. Maintenance The dumpsters shall be inspected weekly and immediately after and storm events. The dumpsters shall be emptied weekly and taken to Inspection: an approved landfill or recycling facility. If trash and construction debris are exceeding the dumpsters’ capacity, the dumpsters shall be emptied more frequently. Waste container lids shall be closed when not in use and at the end of the business day. For waste containers that do not have lids, provide cover or a similarly effective means to minimize the discharge of pollutants.

Description:

5.1.1 Solid or Construction Waste Disposal

T F A R D

Temporary sanitary facilities (portable toilets) shall be provided at the site throughout the construction phase. The portable toilets shall be located in the staging area, away from concentrated flow paths and traffic flow. The portable toilets shall be brought to the site once the staging area has been established. All sanitary waste shall be collected from the portable facilities on a regular basis. The portable toilets shall be inspected weekly for evidence of leaking holding tanks. Toilets with leaking holding tanks shall be removed from the site and replaced with new portable toilets.

Installation Schedule: Maintenance and Inspection:

Description:

Good Housekeeping BMPs

25

All hazardous waste materials such as oil filters, petroleum products, paint, and equipment maintenance fluids shall be stored in structurally sound and sealed shipping containers, within the hazardous materials storage area. Hazardous waste materials shall be stored in appropriate and clearly marked containers and segregated from other non-waste materials. Secondary containment shall be provided for all waste materials in the hazardous materials storage area and shall consist of commercially available spill pallets. Additionally, all hazardous waste materials shall be disposed of in accordance with federal, state, and municipal regulations. Hazardous waste materials shall not be disposed of into the on-site dumpsters. All personnel shall be instructed regarding proper procedures for hazardous waste disposal. Notices that state these procedures shall be posted in the office trailer and the individual who manages day-to-day site operations shall be responsible for seeing that these procedures are followed. Shipping containers used to store hazardous waste materials shall be installed once the site materials storage area has been installed. The hazardous waste material storage areas shall be inspected weekly and after storm events. The storage areas shall be kept clean, well organized, and equipped with ample cleanup supplies as appropriate for the materials being stored. Material safety data sheets, material inventory, and emergency contact numbers shall be maintained in the office trailer.

5.1.4 Hazardous Materials and Waste

Installation Schedule: Maintenance and Inspection:

Description:

5.1.3 Sanitary and Septic Waste

construction wastes are exceeding the dumpsters’ capacity, the dumpsters shall be emptied more frequently.

5.3

5.2

All fertilizers, herbicides, insecticides and pesticides shall be stored in accordance with local, state, and federal regulations. At a minimum these materials shall be covered with plastic sheeting or a temporary roof to prevent contact with rainwater.

T F A R D

All hazardous-waste materials such as oil filters, petroleum products, paint, and equipment maintenance fluids shall be stored in structurally sound and sealed containers under cover within the storage area.

Construction equipment and maintenance materials shall be stored at the combined staging area and materials storage areas. A watertight shipping container shall be used to store hand tools, small parts, and other construction materials. Nonhazardous building materials such as packaging material (wood, plastic, and glass), and construction scrap material (brick, wood, steel, metal scraps, and pipe cuttings) shall be stored in a separate covered storage facility adjacent to the shipping container.

Description:

Good Housekeeping BMPs

26

A designated temporary, above-grade concrete washout area shall be constructed. The temporary concrete washout area shall be constructed with a recommended minimum length and minimum width of 10 feet, but with sufficient quantity and volume to contain all liquid and concrete waste generated by washout operations. The washout area shall be lined with plastic sheeting at least 10 mils thick and free of any holes or tears. Signs shall be posted marking the location of the washout area to ensure that concrete equipment operators use the proper facility.

5.3.1 Concrete Washout

DESIGNATE WASHOUT AREAS

Very large items, such as framing materials and stockpiled lumber, shall be stored in the open in the materials storage area. Such materials shall be elevated on wood blocks to minimize contact with runoff. Installation The materials storage area shall be installed after grading and before any Schedule: infrastructure is constructed at the site. Maintenance The storage area shall be inspected weekly and after storm events. The and storage area shall be kept clean, well organized, and equipped with ample Inspection: cleanup supplies as appropriate for the materials being stored. Perimeter controls, containment structures, covers, and liners shall be repaired or replaced as needed to maintain proper function.

Description:

ESTABLISH PROPER MATERIAL STAGING AREAS

T F A R D Installation Schedule:

Description:

Good Housekeeping BMPs

27

A designated temporary, above-grade washout area shall be constructed as needed for the washout and cleanout of stucco, paint, or other non-hazardous construction materials. The temporary washout area shall be a leak-proof container with sufficient volume to contain all liquid and waste generated by washout operations. The temporary washout shall be sited outside of all buffer zones. The washout area shall be constructed as needed.

5.3.2 Applicators, Containers and Paint Washout

Design Specifications: 1. Temporary concrete washout type Above Grade shall be constructed as shown above, with a recommended minimum length and minimum width of 10 feet. 2. The washout shall be a minimum of 50 feet from storm drain inlets. 3. Plastic lining shall be free of holes, tears, or other defects that compromise the impermeability of the material.

Installation Schedule: Maintenance and Inspection:

Concrete pours shall not be conducted during or before an anticipated storm event. Concrete mixer trucks and chutes shall be washed in the designated area or concrete wastes shall be properly disposed of off-site. When the temporary washout area is no longer needed for the construction project, the hardened concrete and materials used to construct the area shall be removed and disposed of according to the maintenance section below, and the area shall be stabilized. The washout area shall be constructed before concrete pours occur at the site. The washout areas shall be inspected daily to ensure that all concrete washing is being discharged into the washout area, no leaks or tears are present, and to identify when concrete wastes need to be removed. The washout areas shall be cleaned out once the area is filled to 75 percent of the holding capacity. Once the area’s holding capacity has been reached, the concrete wastes shall be allowed to harden; the concrete shall be broken up, removed, and taken to an approved landfill for disposal or recycled on-site or offsite in accordance with applicable laws. The plastic sheeting shall be replaced if tears occur during removal of concrete wastes from the washout area.

5.5

5.4

Description:

DISCHARGES

AND

CONTROL

Good Housekeeping BMPs

28

All equipment and vehicle washing shall be performed off-site, except as required for wheel washes and concrete washout areas.

ALLOWABLE NON-STORMWATER EQUIPMENT / VEHICLE WASHING

Several types of vehicles and equipment will likely be used on-site throughout the project, including graders, scrapers, excavators, loaders, paving equipment, rollers, trucks and trailers, backhoes, and forklifts. All major equipment/vehicle fueling and maintenance shall be performed outside of wetland buffer zones. When vehicle fueling must occur on-site, the fueling activity shall occur in the staging area. Only minor equipment maintenance shall occur on-site. All equipment fluids generated from maintenance activities shall be disposed of into designated drums stored on spill pallets in accordance with the Material Handling and Waste Management Section. Absorbent, spill-cleanup materials and spill kits shall be available at the combined staging and materials storage area. Drip pans shall be placed under all equipment receiving maintenance and vehicles and equipment parked overnight. Installation BMPs implemented for equipment and vehicle maintenance and fueling Schedule: activities shall begin at the start of the project. Maintenance Inspect equipment/vehicle storage areas weekly and after storm events. and Vehicles and equipment shall be inspected on each day of use. Leaks shall Inspection: be repaired immediately, using dry cleanup measures where possible and eliminating the source of the discharge. Problem vehicle(s) or equipment shall be removed from the project site. Keep ample supply of spill-cleanup materials on-site and immediately clean up spills and dispose of materials properly. Do not clean surfaces by hosing-down the area

Description:

T F A R D

The washout areas shall be inspected daily to ensure that all washing is being discharged into the washout area, no leaks or tears are present, and to identify when wastes need to be removed. The washout areas shall be cleaned out once the area is filled to 75 percent of the holding capacity. Liquid wastes shall be disposed of in accordance with applicable Federal and State requirements and shall not be discharged into drainage systems.

ESTABLISH PROPER EQUIPMENT/VEHICLE FUELING AND MAINTENANCE PRACTICES

Maintenance and Inspection:

5.7

5.6

T F A R D Description:

Good Housekeeping BMPs

29

Discharges from fertilizers containing nitrogen and phosphorus shall be minimized. Fertilizers shall be applied at rates and amounts consistent with the manufacture’s specification, and shall at no time exceed local, state, or federal specifications. See project landscape specifications for acceptable fertilizers that can be used for the project.

FERTILIZER DISCHARGE RESTRICTIONS

i.

Employee Training: All employees shall be trained as detailed in the Inspection and Maintenance section of this report. ii. Vehicle Maintenance: Vehicles and equipment shall be maintained off-site. All vehicles and equipment including subcontractor vehicles shall be checked for leaking oil and fluids. Vehicles leaking fluids shall not be allowed on-site. iii. Hazardous Material Storage: Hazardous materials shall be stored in accordance with this report and federal and municipal regulations. iv. Spill Kits: Spill kits shall be kept within the materials storage area. Spills: All spills shall be cleaned up immediately upon discovery. Spent absorbent materials and rags shall be hauled off-site immediately after the spill is cleaned up for disposal at an approved landfill. Spills large enough to discharge to surface water shall be reported to the National Response Center at 1-800-424-8802 and MA DEP at 617-792-7653. v. Material safety data sheets: A material inventory and emergency contact information shall be maintained at the on-site project trailer. Installation The spill prevention and control procedures shall be implemented once Schedule: construction begins on-site. Maintenance All personnel shall be instructed the correct procedures for spill prevention and and control. Notices that state these practices shall be posted in the office Inspection: trailer, and the individual who manages day-to-day site operations shall be responsible for seeing that these procedures are followed.

Description:

SPILL PREVENTION AND CONTROL PROCEDURES

Installation N/A Schedule: Maintenance N/A and Inspection:

x x x x x x x x x

Water Used to Control Dust Uncontaminated Excavation Dewatering Landscape Irrigation Fire Hydrant Flushing Firefighting Potable Water including uncontaminated waterline flushing Non-Detergent Laden Vehicle Wash Water Foundation or Footing Drains Uncontaminated air conditioning or compressor condensate

The following is a list of allowable non-stormwater discharges:

T F A R D

Good Housekeeping BMPs

30

Any changes in construction activities that produce other allowable non-stormwater discharges shall be identified, and the SWPPP shall be amended and the appropriate erosion and sediment control shall be implemented.

ALLOWABLE NON-STORMWATER DISCHARGE MANAGEMENT

Except for water used to control dust and irrigation water, the above discharges shall not be routed to areas of exposed soil.

5.8

Fertilizers shall be applied at an appropriate time of year, timed to coincide as closely as possible to the period of maximum vegetation uptake and growth. Avoid applying fertilizers before heavy rains. Do not apply fertilizers to frozen ground or stormwater conveyance channels flowing with water. Maintenance N/A and Inspection:

Installation Schedule:

6.2

T F A R D

The basins shall be inspected weekly and after storm events greater than 0.5 inches during construction. The area shall be checked for signs of erosion, seepage, and structural damage. Erosion, seepage, and structural damage shall be repaired immediately. The temporary sediment riser shall be checked for any damage or obstructions and any damage found shall be repaired and obstructions removed. Immediately after the completion of construction, the plant material shall be watered for 14 consecutive days unless there is sufficient natural rainfall. The area shall be monitored until final stabilization is reached. Following completion of site construction and final stabilization, maintenance and inspection responsibilities shall be taken over by the Owner in accordance with the Long-Term Pollution Prevention Plan and Long-Term Operation & Maintenance Plan.

Infiltration basins shall be excavated during earthwork construction.

Design Specifications: Installation Schedule: Maintenance and Inspection:

Description:

Final Stabilization

31

See Section 5 for maintenance and inspection procedures for the grass drainage channel. Following completion of site construction and final stabilization, maintenance and inspection responsibilities shall be taken over by the Owner in accordance with the Long-Term Pollution Prevention Plan and Long-Term Operation & Maintenance Plan.

Grass drainage channels shall be installed before site grading begins.

Some of the grass drainage channels shall remain as a permanent stormwater management structures for the site. The channels shall convey runoff to stormwater inlets throughout the site. Install according to sitework specifications and details.

GRASS DRAINAGE CHANNELS

Design Specifications: Installation Schedule: Maintenance and Inspection:

Infiltration basins shall be protected from stormwater runoff from the disturbed site during construction. Riprap spillways shall be constructed as detailed on the site plan. Install according to sitework specifications and details.

INFILTRATION BASIN

6.1 Description:

POST-CONSTRUCTION BMPS

6.0

FINAL STABILIZATION

T F A R D

Preparing the soil for vegetative or non-vegetative stabilization; applying mulch or other non-vegetative product to the exposed area; seeding or planting the exposed area; starting any of the activities in listed above on a portion of the area to be stabilized, but not on the entire area; and finalizing arrangements to have stabilization product fully installed in compliance with the applicable deadline for completing stabilization.

For vegetative stabilization, all activities necessary to initially seed or plant the area to be stabilized; and/or For non-vegetative stabilization, the installation or application of all such non-vegetative measures.

7.1

Description:

Final Stabilization

32

Permanent seeding shall be applied immediately after the final design grades are achieved on portions of the site but no later than 7 days after construction activities have permanently ceased. After the entire site is stabilized, any sediment that has accumulated shall be removed and hauled off-site for disposal at an approved landfill. Construction debris, trash and temporary BMPs (including silt fences, material storage areas, sanitary toilets, and inlet protection) shall also be removed and any areas disturbed during removal shall be seeded immediately. Seeding shall be performed in accordance to the Site Plans and Landscape Specifications for the project.

PERMANENT SEEDING

The following sections detail the management practices proposed to achieve final stabilization of the site.

x

x

As soon as practicable, but no later than 7 calendar days after the initiation of soil stabilization measures the following activities are required to be completed:

x

x x x x

In the context of this provision, “immediately” means as soon as practicable, but no later than the end of the next work day, following the day when the earth-disturbing activities have temporarily or permanently ceased. The following activities constitute the initiation of stabilization:

In compliance with the Construction General Permit, soil stabilization measures must be implemented immediately whenever earth-disturbing activities are temporarily or permanently ceased on any portion of the site. Earth-disturbing activities are temporarily ceased when clearing, grading, and excavation within any area of a site that will not include a permanent structure will not resume for a period of 7 or more calendar days, but such activities will resume in the future.

7.0

Maintenance and Inspection:

Installation Schedule:

T F A R D

Final Stabilization

33

Seeding shall occur at portions of the site where construction activities have permanently ceased shall be stabilized, as soon as possible but no later than 14 days after construction ceases. All seeded areas shall be inspected weekly during construction activities for failure and after storm events until a dense cover of vegetation has been established. If failure is noticed at the seeded area, the area shall be reseeded, fertilized, and mulched immediately. After construction is completed at the site, permanently stabilized areas shall be monitored until final stabilization is reached.

INSPECTIONS

8.1

Inspections and Maintenance

For detailed inspection procedures, see Sections 4 and 5.

34

Utility line installation, pipeline construction, and other examples of long, narrow, linear construction activities may limit the access of inspection personnel to the areas described in the above paragraph. Inspection of these areas could require that vehicles compromise temporarily or even permanently stabilized areas, cause additional disturbance of soils, and increase the potential for erosion. In these circumstances, controls shall be inspected on the same frequencies as other construction projects, but representative inspections may be performed. For representative inspections, personnel shall inspect controls along the construction site for 0.25 mile above and below each access point where a roadway, undisturbed right-of-way, or other similar feature intersects the construction site and allows access to the areas described above. The conditions of the controls along each inspected 0.25 mile segment may be considered as representative of the condition of controls along that reach extending from the end of the 0.25 mile segment to either the end of the next 0.25 mile inspected segment, or to the end of the project, whichever occurs first.

T F A R D

Inspections shall include all areas of the site disturbed by construction activity and areas used for storage of materials that are exposed to precipitation. Inspectors shall look for evidence of, or the potential for, pollutants entering the storm water conveyance system. Sedimentation and erosion control measures identified in the SWPPP shall be observed to ensure proper operation. Discharge locations shall be inspected to ascertain whether erosion control measures are effective in preventing significant impacts to waters of the United States, where accessible. Where discharge locations are inaccessible, nearby downstream locations shall be inspected to the extent that such inspections are practicable. Locations where vehicles enter or exit the site shall be inspected for evidence of off-site sediment tracking.

Inspections of the site will be performed once every 7 days and within 24 hours of the end of a storm event of 0.25-inch or greater unless otherwise specified. The inspections will verify that all BMPs required are implemented, maintained, and effectively minimizing erosion and preventing stormwater contamination from construction materials.

8.1.1 Inspection Schedule and Procedures

INSPECTIONS AND MAINTENANCE

8.0

8.3

8.2

T F A R D

See Appendix F – Corrective Action Log.

Inspections and Maintenance

35

If it is determined the stormwater controls have not been installed as required, or that they are not functioning adequately corrective action is required within 7 calendar days.

The corrective action log describes repairs, replacements, and maintenance of BMPs undertaken as a result of the inspections and maintenance procedures. Additionally, remedies of permit violations and clean and proper disposal of spills, releases other deposits should be recorded.

CORRECTIVE ACTION LOG

If earth-disturbing activities are suspended due to frozen conditions inspections can be temporarily suspended until a thaw occurs.

Once an area is stabilized, inspections may be reduced to once per month. If construction resumes at the stabilized area the inspection frequency shall increase as outlined in section 8.1.

REDUCTIONS IN INSPECTION FREQUENCY

For a copy of the inspection report template, see Appendix E.

Inspection reports are required to be completed within 24-hours of an inspection. If corrective actions are identified by the Inspector during the inspection, he/she shall notify and submit a copy of the inspection report to the Operator(s). For corrective actions identified, the project managers shall be responsible for initiating the corrective action within 24 hours of the report and completing maintenance as soon as possible or before the next storm event. For any corrective actions requiring a SWPPP amendment or change to a stormwater conveyance or control design, the project manager shall notify the Owner, as soon as possible, before initiating the corrective action.

All inspections shall be coordinated with a representative from Clean Energy Collective. A Clean Energy Collective representative shall accompany Name of inspector, when possible, during inspections.

9.3

9.2

RECORDKEEPING

9.1

Company/Organization: TBD Name: TBD

9.3.1 Individual(s) Responsible for Training

Record Keeping and Training

36

Prior to the commencement of earth-disturbing activities or pollutant-generating activities, whichever occurs first, training on the pollution prevention measures outlined in this SWPPP shall be provided to staff and subcontractors.

TRAINING

The log of changes to the SWPPP is maintained in Appendix G and includes additions of new BMPs, replacement of failed BMPs, significant changes in the activities or their timing on the project, changes in personnel, changes in inspection and maintenance procedures and update to site plans.

LOG OF CHANGES TO THE SWPPP

Date(s) when an area is either temporarily or permanently stabilized: See Appendix I – Grading and Stabilization Activities Log

Date(s) when construction activities temporarily or permanently cease on a portion of the site: See Appendix I – Grading and Stabilization Activities Log

T F A R D

Date(s) when major grading activities occur: See Appendix I – Grading and Stabilization Activities Log

The following records shall be kept at the project site and shall be available for inspectors to review. These records shall be retained for a minimum period of at least 3 years after the permit is terminated.

A copy of the SWPPP, along with all inspection reports and corrective action logs are required to be stored at an accessible location at the site, and shall be made available upon request of the EPA, or state or local agency approving stormwater management plans.

RECORDKEEPING AND TRAINING

9.0

Record Keeping and Training

T F A R D

37

Formal training shall be provided to all staff and subcontractors with specific stormwater responsibilities, such as installing and maintaining BMPs. The formal training shall cover all design and construction specifications for installing the BMPs and proper procedures for maintaining each BMP. Formal training shall occur before any BMPs are installed on the site. (See Appendix J – Training Log)

Informal training shall be conducted for all staff, including subcontractors, on the site. The training shall be conducted primarily via tailgate sessions and shall focus on avoiding damage to stormwater BMPs and preventing illicit discharges. The tailgate sessions shall be conducted biweekly and shall address the following topics: Erosion Control BMPs, Sediment Control BMPs, Non-Stormwater BMPs, Waste Management and Materials Storage BMPs, and Emergency Procedures specific to the construction site. (See Appendix J – Training Log)

9.3.2 Description of Training Conducted

SIGNATURE, PLAN REVIEW, AND MAKING PLANS AVAILABLE

10.1

T F A R D

NOTICE OF PERMIT COVERAGE

x

x x x

Certification and Notification

38

The NPDES Permit Tracking Number, A contact name and phone number for obtaining additional construction site information, The Uniform Resource Locator (URL) for the SWPPP (if available), or the following statement: “If you would like to obtain a copy of the Stormwater Pollution Prevention Plan (SWPPP) for this site, contact the EPA Regional 1 Office at (617) 918-1038, The following statement “If you observe indicators of stormwater pollutants in the discharge or in the receiving waterbody, contact the EPA through the following website: https://www.epa.gov/enforcement/report-environmental-violations.”

A sign must be posted at a safe, publicly accessible location in close proximity to the construction site detailing the permit coverage. The notice must be located so that it is visible from the public road that is nearest to the active part of the construction site, and it must use a font large enough to be readily viewed from a public right-of-way. At a minimum, the notice must include:

10.2

A copy of the SWPPP (including a copy of the Construction General Permit, NOI, and acknowledgement letter from EPA shall be retained at the construction site (or other location easily accessible during normal business hours to EPA, a state, tribal or local agency approving sediment and erosion plans, grading plans, or storm water management plans; local government officials; the operator of a municipal separate storm sewer receiving discharges from the site; and representatives of the U.S. Fish and Wildlife Service or the National Marine Fisheries Service) from the date of commencement of construction activities to the date of final stabilization. A copy of the SWPPP shall be available at a central location on-site for the use of all those identified as having responsibilities under the SWPPP. If an on-site location is unavailable to store the SWPPP when no personnel are present, notice of the plan’s location shall be posted near the main entrance at the construction site.

CERTIFICATION AND NOTIFICATION

10.0

000000RP000

Project Name Stormwater Pollution Prevention Plan (SWPPP) Town, Massachusetts

10.3

Certification and Notification

T F A R D

Signature:________________________________ Date:_______________________

Name:___________________________________ Title:_______________________

39

I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gathered and evaluated the information submitted. Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering the information, the information submitted is, to the best of my knowledge and belief, true, accurate, and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations.

OWNER CERTIFICATION

10.4

Certification and Notification

T F A R D

Signature:________________________________ Date:_______________________

Name:___________________________________ Title:_______________________

40

I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gathered and evaluated the information submitted. Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering the information, the information submitted is, to the best of my knowledge and belief, true, accurate, and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations.

OPERATOR CERTIFICATION

T F A R D

APPENDICES

T F A R D General Location Map

Appendix A

T F A R D

Site Plans

Appendix B

Appendix C

https://www.epa.gov/sites/production/files/2017-02/documents/2017_cgp_final_permit_508.pdf

Construction General Permit

T F A R D

Appendix D NOI and Acknowledgement Letter from EPA

T F A R D

Inspection Reports

Appendix E

The following four pages should be copied and completed for each inspection. All inspection forms should be compiled in a binder to prove compliance with this SWPPP.

Inspections under this SWPPP shall be conducted in accordance with each installed BMPs recommended maintenance requirements. This inspection frequency may be reduced to at least once every month if: a) the entire site is temporarily stabilized, b) runoff is unlikely due to winter conditions (e.g. site is covered with snow, ice, or the ground is frozen), or c) construction is occurring during seasonal arid periods in arid areas and semi-arid areas. If an inspection report is filed according to this modified schedule it shall be noted at the end of the report under the “NOTES” section.

T F A R D

Are there any discharges at the time of inspection? ‰Yes If yes, describe:

‰No

‰ High Winds ‰No

‰ Fog ‰ Snowing Temperature: Have any discharges occurred since the last inspection? ‰Yes If yes, describe:

Weather at time of this inspection? ‰ Clear ‰Cloudy ‰ Rain ‰ Sleet ‰ Other:

Approx. Amount of Precipitation (in):

‰ During storm event ‰ Post-storm event Weather Information Has there been a storm event since the last inspection? ‰Yes ‰No If yes, provide: Storm Start Date & Time: Storm Duration (hrs):

Inspector’s Contact Information Inspector’s Qualifications Describe present phase of construction Type of Inspection: ‰ Regular ‰ Pre-storm event

Inspector’s Title(s)

T F A R D

Start/End Time

Date of Inspection Inspector’s Name(s)

Location

General Information

NPDES Tracking No.

Project Name

Stormwater Pollution Prevention Plan: Inspection Checklist

E-1

BMP

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

Corrective Action Needed and Notes

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

T F A R D

BMP Maintenance Required?

BMP Installed?

E-2

Site-specific BMPs x Number the structural and non-structural BMPs identified in your SWPPP on your site map and list them below (add as many BMPs as necessary). Carry a copy of the numbered site map with you during your inspections. This list will ensure that you are inspecting all required BMPs at your site. x Describe corrective actions initiated, date completed, and note the person that completed the work in the Corrective Action Log.

Are vehicle and equipment fueling, cleaning, and maintenance areas free of spills, leaks, or any other deleterious material?

Are washout facilities (e.g., paint, stucco, concrete) available, clearly marked, and maintained?

Is trash/litter from work areas collected and placed in covered dumpsters?

Is the construction exit preventing sediment from being tracked into the street?

Are storm drain inlets properly protected?

Are discharge points and receiving waters free of any sediment deposits?

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

Maintenance Required?

E-3

Corrective Action Needed and Notes

T F A R D

‰Yes ‰No

Are natural resource areas (e.g., streams, wetlands, mature trees, etc.) protected with barriers or similar BMPs?

‰Yes ‰No

‰Yes ‰No

Are all slopes and disturbed areas not actively being worked properly stabilized?

Are perimeter controls and sediment barriers adequately installed (keyed into substrate) and maintained?

Implemented?

BMP/activity

Overall Site Issues Below are some general site issues that should be assessed during inspections. Customize this list as needed for conditions at your site.

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

‰Yes ‰No

Are non-stormwater discharges (e.g., wash water, dewatering) properly controlled?

(Other)

Corrective Action Needed and Notes

Date:_____________________

Signature:_________________________________________________________

___________________________________________________________________________

Print name and title:

E-4

“I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gathered and evaluated the information submitted. Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering the information, the information submitted is, to the best of my knowledge and belief, true, accurate, and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations.”

CERTIFICATION STATEMENT

Describe any incidents of non-compliance not described above:

Non-Compliance

T F A R D

‰Yes ‰No

‰Yes ‰No

Are materials that are potential stormwater contaminants stored inside or under cover?

Maintenance Required?

Implemented?

BMP/activity

T F A R D

Corrective Action Log

Appendix F

Date

Additional Action Items

T F A R D

Activity Description

F-1

Use this form to note the date and activity for accurate record keeping (make additional copies as necessary). Examples include the restaking or reinforcement of the erosion control barrier, site watering to prevent dust erosion, street sweeping, equipment and machinery repair, etc.

Corrective Action Log

Appendix G

Based on the results of an inspection, the SWPPP shall be modified as necessary to include additional or modified BMPs designed to correct problems identified. Revisions to the SWPPP shall be completed within seven (7) calendar days following the inspection. Implementation of these additional or modified BMPs shall be accomplished as described in Subpart 3.6B of the Construction General Permit (located in Appendix C).

The SWPPP shall be amended if during inspections or investigations by site staff, or by local, state, tribal or federal officials, it is determined that the SWPPP is ineffective in eliminating or significantly minimizing pollutants in storm water discharges from the construction site.

The SWPPP, including the site plans, shall be amended whenever there is a change in design, construction, operation, or maintenance at the construction site that has or could have a significant effect on the discharge of pollutants to the waters of the United States that has not been previously addressed in the SWPPP.

SWPPP Amendment Log

T F A R D

Amendment No.

Date of Amendment

T F A R D

Description of the Amendment

SWPPP Amendment Log

G-1

Amendment Prepared by (Name(s) and Title)

Appendix H Subcontractor Certifications/Agreements

T F A R D

T F A R D

Date:

Title:

Signature:

Type of construction service to be provided:

Telephone Number:

Address:

Company:

This certification is hereby signed in reference to the above named project:

I certify under the penalty of law that I have read and understand the terms and conditions of the SWPPP for the above designated project and agree to follow the practices described in the SWPPP.

Each subcontractor engaged in activities at the construction site that could impact stormwater must be identified and sign the following certification statement:

As a subcontractor, you are required to comply with the Stormwater Pollution Prevention Plan (SWPPP) for any work that you perform on-site. Any person or group who violates any condition of the SWPPP may be subject to substantial penalties or loss of contract. You are encouraged to advise each of your employees working on this project of the requirements of the SWPPP. A copy of the SWPPP is available for your review at the office trailer.

Operator(s):

Project Title:

Project Number:

SUBCONTRACTOR CERTIFICATION STORMWATER POLLUTION PREVENTION PLAN

Sample Subcontractor Certifications/Agreements

Appendix I

Site Plans in Appendix B should be annotated to indicate areas where final stabilization has been accomplished and no further construction-phase permit requirements apply.

Grading and Stabilization Activities Log

T F A R D

Date

Description

T F A R D

Location on Property

Grading and Stabilization Activities Log

I-1

The following records are to be kept by each Site Operator throughout the construction period and maintained in the SWPPP. Insert additional documentation for record keeping as necessary.

T F A R D

Training Log

Appendix J

Date

Training Log Attendee

T F A R D

Training Topic

Signature of Training Coordinator

J-1

T F A R D

Delegation of Authority

Appendix K

Date:

Signature:

Title:

Company:

Name:

I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gathered and evaluated the information submitted. Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering the information, the information submitted is, to the best of my knowledge and belief, true, accurate, and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations.

By signing this authorization, I confirm that I meet the requirements to make such a designation as set forth in Appendix I of EPA’s Construction General Permit (CGP), and that the designee above meets the definition of a “duly authorized representative” as set forth in Appendix I.

T F A R D

________________________________________ (name of person or position) ________________________________________ (company) ________________________________________ (address) ________________________________________ (city, state, zip) ________________________________________ (phone)

I, _______________________ (name), hereby designate the person or specifically described position below to be a duly authorized representative for the purpose of overseeing compliance with environmental requirements, including the Construction General Permit, at the ____________________________________ construction site. The designee is authorized to sign any reports, stormwater pollution prevention plans and all other documents required by the permit.

Delegation of Authority

Sample Delegation of Authority Form

Appendix L Endangered Species Documentation

T F A R D

Appendix M

Historic Preservation Documentation

T F A R D

Appendix N Temporary Sediment Basin Sizing Calculations

T F A R D

Appendix O

Natural Buffer Equivalency Calculations

T F A R D

September 19, 2017 Department of Land Use, Planning & Permitting Hopkinton Planning Board 80 South Main Street Hopkinton, MA 01748 Attn.: Ms. Jennifer Burke, Principal Planner Re:

Hopkinton – 147 Lumber Street – CEC Solar Site Plan Review Peer Review

Dear Ms. Burke: BETA Group, Inc. (BETA) has reviewed the Application for Special Permit, Stormwater Permit and Notice of Intent for the proposed CEC Solar #1206, LLC facility located at 147 Lumber Street in accordance with BETA’s agreement with the Town dated March 31, 2016. This letter is provided to outline BETA’s findings, comments and receomendations. BASIS OF REVIEW The following documents were received by BETA and will form the basis of the review: ·

·

·

·

Application for Special Permit dated August 24, 2017 including the following attachments: o Cover Letters o Project Narrative o Clean Energy Results Document o Abutter Information o Application for Special Permit o Stormwater Management Information Application for Stormwater Management Permit dated August 24, 2017 including the following attachments: o Cover Letter o Abutter Information o Stormwater Management Permit o Exhibits Application o Stormwater Management Report Notice of Intent dated August 24, 2017 including the following attachments: o Cover Letter o Stormwater Management Information o Notice of Intent Forms o Wetland Boundary Documentation o Project Narrative o Plans o Abutter Information Site Plans (19 sheets) entitled “CEC Solar #1206. LLC in Hopkinton, Massachusetts (Middlesex County)” dated August 10, 2017 prepared by Beals and Thomas, Inc., Southborough, MA

Review by BETA will include the above items along with the following: · · · ·

Town of Hopkinton Zoning Bylaws revised through October, 2016 Town of Hopkinton Massachusetts Zoning Map dated May 7, 2012 Water Resource Protection Overlay District (Map) Hopkinton, MA March 2011 Town of Hopkinton Chapter 172 Stormwater Management and Erosion Control Bylaw

BETA GROUP, INC. 315 Norwood Park South, 2nd Floor, Norwood, MA 02062 P: 781.255.1982 | F: 781.255.1974 | W: www.BETA-Inc.com

Department of Land Use, Planning & Permitting September 19, 2017 Page 2 of 6 · ·

Town of Hopkinton Stormwater Management Regulations, amended August 11, 2014 Town of Hopkinton Wetlands Protection Bylaw and Regulations, updated June 16, 2003

INTRODUCTION The project site includes two parcels, 147 Lumbers Street and an adjacent landlocked Parcel 3 to the east totaling 41.5± acres. The project area portions of the parcels are currently wooded. The site is located within the Agriculture (A) Zoning District and portions are within the Water Resources Protection Overlay District (WRPOD-1). The submitted documents indicate that the 2.9 MW (DC) solar array installation will occupy 11.4± acres. The project proposes work within wetland resource areas that requires conforming to the Massachusetts Wetlands Protection Act and Hopkinton Wetlands Protection Bylaw and obtaining an Order of Conditions from the Hopkinton Conservation Commission. The project is proposing stormwater management system expansion which will need to comply with the MassDEP Stormwater Management Standards and the Hopkinton Stormwater Management Bylaw and regulations. GENERAL G1.

Provide details or catalog cuts for equipment to be installed (inverters, switchgear, etc. ).

G2.

Provide AutoTURN plan that indicates access drive and turnaround can accommodate maintenance and emergency vehicles.

ZONING BETA reviewed the Hopkinton Zoning Bylaws in the following applicable sections: Article V Agricultural (A) District The majority of the project is located within the Agricultural District. The parcel is currently nonconforming relative to minimum lot frontage, and the project does not propose a change. Except for frontage, the project meets the minimum dimensional requirements of this section including lot area, lot coverage, setbacks and building coverage. Article XII Water Resources Protection Overlay District (WPROD-1) The project is also located within the Water Resources Protection Overlay District. MassDEP requires that solar arrays be modeled as impervious area, unconnected, therefore the project will exceed the threshold for impervious area. The project however, incorporates required systems of groundwater recharge. Article XVIII Supplementary Regulations (as applicable) The project proposes clearing up to the property line. The proposed nonresidential use does not meet the minimum required buffer zone (75 feet for Agricultural District). The following sections of the Zoning Bylaw are applicable. §210.121.1.A. - A lot which contains a nonresidential use in a Residence A, Residence B, Residence Lake Front or Agricultural District shall contain a buffer area at the perimeter of the lot. The buffer area shall consist of trees, shrubs, vegetation and topographic features sufficient to separate and/or visually screen the use from abutting properties in a residential district and shall be located on the same lot as the nonresidential use.

Department of Land Use, Planning & Permitting September 19, 2017 Page 3 of 6 §210.121.1.B. - The buffer shall be no less than 25 feet wide in a Residence A District; 50 feet wide in a Residence B and Residence Lake Front District; and 75 feet wide in an Agricultural District…. §210.121.1.E. - Upon a finding by the Planning Board that a buffer of lesser width would be sufficient to screen and/or separate the use from adjacent property, the width of the buffer may be reduced. … In those circumstances, it is the intent of the Board not to waive the buffer requirement, but, rather, to provide alternative screening arrangements, such as fencing and planting where possible. Z1.

Revise the design to provide required buffer/screening or provide alternative screening arrangements and request finding from the Planning Board in accordance with §210.121.1.E.

Article XXXI Commercial Solar Photovoltaic Installations Commercial solar photovoltaic installations shall conform to the following provisions: A.

B.

A commercial solar photovoltaic installation may be erected, upon the issuance of a special permit by the Planning Board, on a lot containing a minimum of three (3) acres. Lot contains in excess of 3 acres – conforms. All setback, yard, buffer and screening requirements applicable in the zoning district in which the installation is located shall apply. See Z1 above.

C.

All security fences surrounding the installations shall be set back from the property line a distance equal to the setback requirement applicable to buildings within the zoning district in which the installation is located. Security fencing located outside setback areas – conforms.

D.

The provisions of Article XX, Site Plan Review, shall not apply to commercial solar photovoltaic installations. Site Plan Review not required. The visual impact of the commercial solar photovoltaic installation, including all accessory structures and appurtenances, shall be mitigated. All accessory structures and appurtenances shall be architecturally compatible with each other. Whenever reasonable, structures shall be shielded from view by vegetation and/or joined and clustered to avoid adverse visual impacts. Methods such as the use of landscaping, natural features and fencing may be utilized. See Z1 above.

E.

F.

Lighting shall not be permitted unless required by the Planning Board or by the State Building Code. Where used, lighting shall be directed downward and full cut-off fixtures shall be used. No lighting proposed – conforms.

G.

All utility connections from the commercial solar photovoltaic installation shall be underground unless otherwise specifically permitted otherwise by the Planning Board in the special permit. Electrical transformers and inverters to enable utility interconnections may be above ground if required by the utility provider. Plans indicate underground electric except for the pad mounted switchgear, disconnect and interconnect poles near Lumber Street – conforms.

Approval Criteria: In reviewing any application for a special permit pursuant to this Article, the Planning Board shall give due consideration to promoting the public health, safety, convenience and welfare; shall encourage the most appropriate use of land and shall permit no building or use that is injurious, noxious, offensive or detrimental to its neighborhood. Before the Planning Board may issue such a special permit, it shall determine each of the following: (1)

The commercial solar photovoltaic installation conforms to the provisions of this Article. See above.

Department of Land Use, Planning & Permitting September 19, 2017 Page 4 of 6 (2)

The commercial solar photovoltaic installation will not be detrimental to the neighborhood or the Town. The project will not generate traffic, noise and light impacts. It will not require town services. See Z1

(3)

Environmental features of the site and surrounding areas are protected, and specifically surrounding areas will be protected from the proposed use by provision of adequate surface water drainage. See comments on stormwater management and wetlands below.

(4)

The proposed use is in harmony with the general purpose and intent of this Chapter.

Stormwater Management Permit Review The project is subject to the Stormwater Management Standards (Stormwater Regulations (SWR) 7.0). The following are the 10 standards and relative compliance provided by the submitted documentation. No untreated stormwater (Standard Number 1): No new stormwater conveyances (e.g., outfalls) may discharge untreated stormwater directly to or cause erosion in wetlands or waters of the Commonwealth. The project does not propose untreated stormwater discharges to wetlands. Provided other comments as it relates to stormwater management are addressed – compliance with standard will be achieved. Post-development peak discharge rates (Standard Number 2): Stormwater management systems must be designed so that post-development peak discharge rates do not exceed pre-development peak discharge rates. Calculations provided indicate the project will not increase in peak runoff flows for the 2, 10, 25 and 100 year storm events utilizing rainfall data from the Northeast Regional Climate Center. The model for the proposed condition uses a “meadow, non-grazed” to approximate the surface characteristic when fully constructed. However, once constructed, the surface will not receive rainfall evenly. Some areas under arrays will receive direct rainfall and based on how runoff travels once it falls off the array (sometime under the array and sometime parallel based on the topography) and there will also be some maintenance (mowing) of the grass. SW1.

Based on this BETA recommends revising the calculations using “>75% Grass cover” for CN values under arrays to more closely model expected conditions.

SW2.

Use “water surface” to compute CN values for infiltration basins.

SW3.

P-DA-1B Tc path for developed condition will include flow over grass, revise calculation.

Recharge to groundwater (Standard Number 3): Loss of annual recharge to groundwater should be minimized through the use of infiltration measures to maximum extent practicable. The site is comprised of predominately soils rated in Hydrologic Soil Groups (HSG) A and B in upland areas. The plans indicate that the three infiltration basin areas are to be used as temporary infiltration basins during construction. SW4.

Provide provision to protect infiltrative properties of basins during construction.

SW5.

Provide soil test data within limits of stormwater infiltration basins to identify seasonal high groundwater elevations and to confirm soil classification.

The plans include three infiltration basins but exfiltration is not included in the HydroCAD model. SW6.

Recommend including expected exfiltration based on Rawls rates for the soils confirmed by soil testing to quantify the proposed volume of runoff from the development.

Department of Land Use, Planning & Permitting September 19, 2017 Page 5 of 6 80% TSS Removal (Standard Number 4): For new development, stormwater management systems must be designed to remove 80% of the annual load of Total Suspended Solids. Stormwater runoff from the site discharges to the adjacent wetland areas. The plans include recharge infiltration basins to provide recharge. Higher Potential Pollutant Loads (Standard Number 5): Stormwater discharges from Land Uses with Higher Potential Pollutant Loads require the use of specific stormwater management BMPs. This project documentation does not propose Land Uses with Higher Potential Pollutant Loads – not applicable. Critical Areas (Standard Number 6): Stormwater discharges to critical areas must utilize certain stormwater management BMPs approved for critical areas. A portion of the project area is located with a Zone II Wellhead Protection Area. Project is not likely to generate pollutants that would adversely impact groundwater supplies. It provides treatment of runoff and recharge via infiltration basins – complies with standard. Redevelopment (Standard Number 7): Redevelopment of previously developed sites must meet the Stormwater Management Standards to the maximum extent practicable. This project does not meet the definition of a redevelopment – not applicable. Construction Period Erosion and Sediment Controls (Standard Number 8): Erosion and sediment controls must be implemented to prevent impacts during construction or land disturbance activities. The project site is greater than 1 acre in area and land disturbance activities will require a Notice of Intent with EPA and a Stormwater Pollution Prevention Plan (SWPPP). Site Preparation Plans and a draft Stormwater Pollution Prevention Plan (SWPPP) were provided. SW7.

Include erosion control barriers on sheet C2.2.

SW8.

To reduce potential spread of invasive species, recommend using staked compost filter sock or straw wattle in lieu of staked hay bales.

SW9.

Temporary Sediment Basin Sizing Calculations are not included in Appendix K, provide.

SW10. Recommend that a condition be included that requires submission of copy of NOI submitted to EPA and the final completed and signed SWPPP to Planning Board prior to construction. Operations/Maintenance plan (Standard Number 9): A long-Term Operation and Maintenance Plan shall be developed and implemented to ensure that stormwater management systems function as designed. An Operation and Maintenance Plan was included in the Stormwater Drainage Report. SW11. Provide the names and daytime telephone numbers and signatures of the Responsible Parties SW12. Include map (preferably 11” x 17”) with the Long-Term Operation and Maintenance Plan (LTOMP) to identify and highlight BMP locations to be maintained. SW13. Include provisions for maintaining vegetative cover and the repairing of areas subject to erosion – Appendix C was not included. SW14. Maintenance plan should also include provisions for selective tree maintenance. SW15. Provide provision to notify Planning Board of ownership change. SW16. Add the Planning Board to the list of parties whom are allowed access to inspect stormwater management system and whom the O&M records (2.3) will be made available. Illicit Discharges (Standard Number 10): All illicit discharges to the stormwater management systems are prohibited. An unsigned Illicit Discharge Compliance Statement was included.

Department of Land Use, Planning & Permitting September 19, 2017 Page 6 of 6 SW17. Provide a signed Illicit Discharge Compliance Statement. WETLANDS Portions of the development area are located within the buffer zone of wetland resources and require an Order of Conditions from the Hopkinton Conservation Commission and MassDEP. Limits of work are shown just outside 50 foot buffer zone of bordering vegetated wetlands and 100 feet from potential vernal pool. Parcel 3 slopes down moderately and uniformly to the east wetland resource areas under existing conditions. The proposed plan includes a swale that intercepts runoff at the buffer zone and routes it to the north to an infiltration basin. W1. Consider alternatives to distribute runoff/recharge more uniformly to mimic current conditions and reduce potential impacts to wetland resource areas. If we can be of any further assistance regarding this matter, please contact us at our office. Very truly yours, BETA Group, Inc.

Philip F Paradis, Jr., PE Associate cc:

Don MacAdam

M:\2 Proposals\2017\9058 Hopkinton - 147 Lumber St\147 Lumber St SW Peer Reveiw 9-19-17.docx

TOWN OF HOPKINTON CENTER SCHOOL RE-USE ADVISORY TEAM _____________________________

TOWN HALL 18 MAIN STREET HOPKINTON, MASSACHUSETTS 01748-3209

Dear Department Head or Chair of Board or Committee, With the upcoming opening of the Marathon Elementary School anticipated in the fall of 2018 the Board of Selectmen formed the Center School Re-use Advisory Team to explore the future of Center School. The Board of Selectmen’s charge to the Team is: The Center School Re-Use Advisory Team will recommend, for the Board of Selectmen’s consideration, a plan for the Center School building and property that will provide the Board with valuable outside viewpoints on the use and development of the property. This plan shall outline the community’s vision for the future use of the property and produce recommendations for the Board’s consideration that align with the aspirations of the community.

The Team would appreciate you completing the attached questionnaire to assist us in completing the Team’s mission. If your Department, Board or Committee expresses an interest in using the Center School property, our Team will follow up with you on a more detailed forecast of your needs / requirements and how Center School would need to be retrofitted / adapted to serve your needs. Please try to think long term when considering future needs – the Team is interested in future needs, not just immediate needs. Please complete and return the survey via email to Elaine Lazarus in the Town Manager’s office at [email protected], or on paper, delivered in person to 80 South St. or mailed to 18 Main St., preferably prior to October 1, 2017, and thank you.

Sincerely, Richard A. Flannery, Chair Center School Re-use Advisory Team

Center School Re-use Advisory Team Department and Board / Committee Questionnaire Department, Board or Committee Name: ______________________________________ 1. Is your Department, Board or Committee familiar with the Center School Building and grounds?

2. Does your Department, Board or Committee have any needs that could involve the use of the Center School building and/or grounds? (For example office space, storage space, gymnasium or recreational activities.)

3. Does your Department, Board or Committee have any suggestions or ideas for a Municipal use for the Center School building or grounds?

4. Does your Department, Board or Committee have any suggestions or ideas for a Community use for the Center School building or grounds?

5. Does your Department, Board or Committee have any other suggestions or ideas for a Private use of Center School building or grounds?

6. Does your Department, Board or Committee have any other suggestions or ideas for the use of Center School building or grounds?

7. Does your Department, Board or Committee have any concerns about the use of the Center School building or grounds?

8. Does your Department, Board or Committee have any other suggestion, idea or question regarding the Center School building or grounds that you would like the Team to consider?

HOPKINTON PLANNING BOARD Monday, August 28, 2017 7:30 P.M. HCAM Studio, 77 Main St./Lower Level, Hopkinton, MA

MINUTES MEMBERS PRESENT: John Ferrari, Chairman, Fran DeYoung, Vice Chairman, David Paul, Amy Ritterbusch, Kelly Karp, Frank D’Urso, Cliff Kistner, Irfan Nasrullah, Muriel Kramer Present: Jennifer Burke, Principal Planner; Cobi Wallace, Permitting Assistant Mr. Ferrari opened the meeting, and summarized the Agenda. 1. Continued Public Hearing – 50-60 West Main Street – Site Plan Review – Phase 3 Golden Pond Expansion Project - Golden Pond Resident Care Corporation Kerry Kunst, Golden Pond Resident Care Corporation, applicant, Wayne Davies, attorney, and Joe Marquedant, J.D. Marquedant & Associates, Inc., surveyor, appeared before the Board. Mr. DeYoung, Planning Board project liaison for this application, opened the continued public hearing. Ms. Burke noted the applicant and his engineer met with her, Don MacAdam, Conservation Commission (ConCom) Administrator, and Phil Paradis, BETA Group, Inc., the Board's engineering consultant, on August 2, primarily to discuss drainage and stormwater basin related issues. She stated she believes the meeting was productive although additional information regarding currently still outstanding issues has not yet been submitted. Mr. Davies stated Mr. Marquedant has talked with BETA and progress has been made, with a few things still to be resolved. He referred to Ms. Burke's summary on page 2 of her memorandum to the Board. He noted during Phase 2 of the Golden Pond expansion project, the Fire Dept. had requested that access between the two buildings be preserved but is now reconsidering that requirement. He noted Golden Pond is currently working on plan modifications, including revised landscape and lighting plans, to reflect the Fire Dept.'s change in approach. Mr. DeYoung noted Mr. Paradis previously had identified a number of issues, and it appears the consultants are working together, therefore perhaps their comments can be consolidated. Mr. D’Urso asked for clarification regarding the status of the stormwater basin issue, and Mr. Davies stated the ConCom has concurrent jurisdiction here but there is no agreement yet. Mr. Marquedant stated they have looked at past data and reached out to the engineer who did the site work for Phase 2 to determine why the basin is not functioning correctly, and hopefully they will be able to come up with a solution. Mr. DeYoung asked if the work on Phase 3 will take care of the issue automatically, and Mr. Davies stated they plan to resolve the outstanding issues with the ConCom. Mr. Paradis stated he has been to the site a couple of times observing conditions firsthand, however, the cause of the problem is a bit of a mystery. He noted as discussed on August 2 there is a lot of available data but more research is needed and he has not heard back from the applicant. Mr. DeYoung suggested the applicant continue working with BETA, and Mr. Marquedant noted he anticipates making progress on the issue.

1

The Board discussed Item 7, Traffic, on the public hearing outline prepared for this proposal. Mr. Marquedant stated a traffic study was submitted and reviewed in 2012, and Ron Müller of Ron Müller & Associates, was asked to look at the impact of Phase 3. He quoted from the summary on page 2 of Mr. Müller's report dated May 2, 2017, and stated traffic impact of this phase will be negligible, maintaining safe traffic flow and pedestrian/vehicle access conditions once construction is done. Mr. Paradis noted BETA agrees with Mr. Müller's conclusions. The Board moved on to the next item on the outline, Building Design. Ms. Burke noted the applicant met with the Design Review Board (DRB), but the members had no specific comments and/or recommendations and there were no changes to the plans as a result of the meeting. Ms. Kramer arrived at this time. Mr. D'Urso asked about the lack of street views, and Mr. Davies noted the building is in the back and the illustrations included in the application are clear in that respect. Mr. D’Urso noted the building can be seen from Elm St. He noted Golden Pond did a good job in Phase 2 and he is not too concerned but thought BETA had asked about it. Ms. Ritterbusch stated the DRB had no concerns and it appears the addition will be tucked in there, but privacy of Phase 2 vs. Phase 3 residents may be an issue. Mr. Davies questioned how that would fall within the DRB jurisdiction and assured the Board it will not be a problem. The Board referred to the Stormwater item on the public hearing outline, and Mr. Davies stated he feels the issue should be continued to the next meeting. Mr. DeYoung asked about the parking lot design, and Mr. Davies noted there will be no significant changes to the lot. Reference was made to snow removal provisions, and Mr. Marquedant noted the current plan sets aside a couple of spaces for temporary snow storage and it has worked out ok since 2012. Mr. Nasrullah asked if Phase 3 will require additional parking spaces, and Mr. Marquedant stated the number of spaces constructed in 2013 satisfies the requirement for the entire expansion project and they have what they need. Mr. Davies stated the facility actually has 14 more spaces than needed under the bylaw. Mr. DeYoung asked about parking spaces for cars belonging to permanent Golden Pond residents, and Mr. Davies noted this is an assisted living facility and a significant number of people don't drive at all. Mr. D’Urso referred to a BETA comment regarding light spillage onto adjacent property, and Mr. DeYoung noted it will be addressed as part of the BETA issues still outstanding. Mr. Davies reminded the Board they are currently still relying on Phase 2 landscaping and lighting plans which will be supplemented for Phase 3 now that the Fire Chief has been a little more flexible with respect to access requirements. Stephen Slaman, Fire Chief, noted the Fire Dept. reviewed the plans a few weeks ago, and is now considering changing its approach with respect to access between the Phase 2 and Phase 3 buildings additional analysis. Mr. Paul asked about landscaping/screening concerns, and Mr. Davies noted they have not been able to provide a new plan but are not aware of any concerns. Mr. DeYoung asked about Utilities, and Mr. Marquedant stated a new water loop and a municipal sewer connection through the emergency access on Elm St. were handled in 2012, and no additional changes are anticipated at this time. Reference was made to BETA's most recent comment letter, and Mr. Marquedant noted it may be necessary to move the sewer force main if during construction is it found to be too close to the footing system for the Phase 3 addition. Ms. Burke asked if the applicant has received an answer from John Westerling, Director of Public Works, with respect to the request for an increase of sanitary flow from the facility, and Mr. 2

Marquedant noted the request was discussed with the Water/Sewer Superintendent but he is still waiting to hear from Mr. Westerling. In response to comments from Board members, Mr. Marquedant indicated he will follow up with Mr. Westerling on behalf of the applicant on a few issues related to this project. Mr. Kistner referred to the BETA comment regarding a retaining wall south of the new building, and Mr. Marquedant noted this issue is part of the access area mentioned by the Fire Chief and may be resolved by a revised design. It was determined to leave the Utilities item open pending the response from the DPW Director. Mr. Paul asked if the applicant would be willing to add curbing along West Main St. as part of this project, and Mr. Kunst stated yes, to the extent that it is similar to what was done further down the street. Mr. Paul noted it would make it look a little nicer and keep sand/salt off the grass. Mr. Marquedant referred to the proposed Construction Management Plan and noted the focus is on the southerly side of the site to address concerns regarding delivery vehicles access and parking for subcontractors during construction. He described the proposed traffic pattern and noted the applicant also controls the property at 62 West Main St. for temporary storage and additional parking. He noted it is felt the proposed arrangement will make sure Golden Pond residents can still use the northerly part of the site for walking and exercise. Ms. Ritterbusch asked about access for emergency vehicles during construction, and Chief Slaman noted he is not sure whether there is a plan yet, noting it was difficult during the first phases as well as the most recent small addition, and perhaps they will need the Police Dept. to monitor the site especially as the facility continues to expand. Ms. Burke asked where the construction workers are going to park, and Mr. Marquedant noted throughout the site and in dedicated spots. Mr. Davies noted a lot of these issues will be under the supervision of the Building Inspector, but if necessary, Golden Pond will find more offsite parking to address any concerns. Mr. Paul read through the draft conditions of approval listed in Ms. Burke's memo to the Board, and stated that 4 out of 7 are construction related. Mr. D'Urso noted these are just draft conditions and the Board may make changes and/or add to them. The Board closed out the Construction Management Plan item, and noted that as far as comments/input from other Boards or Committees are concerned, the project was ok'd by the DRB while an agreement on conservation issues is still outstanding. Ms. Burke noted the ConCom continued its hearing on this proposal to September 18. Mr. Davies summarized the outstanding issues. Ms. Kramer moved to continue the public hearing to September 25, 2017 at 7:30 P.M., Mr. D'Urso seconded the motion, and the Board voted unanimously in favor. 2. Legacy Farms North Villages - Pulte Homes - Request for Signage off Premises Reid Blute, Pulte Homes, proponent, appeared before the Board. Mr. Blute stated Pulte Homes has been in Hopkinton for a number of years developing residential portions of the overall Legacy Farms project, is about to finish the Legacy Farms South and currently in the beginning phases of the Legacy Farms North villages. He noted Pulte Homes up to now had a temporary sales sign for the Legacy Farms South development on the south side of East Main St. near the intersection with Legacy Farms South, and would like to install a similar sign to advertise for the new homes in Legacy Farms North, thinking that simply switching it to the other side of the street would make the most sense. He noted it is important for people to be able to easily locate the new homes which are quite a distance from East Main St., and a sign on the main road would 3

address that need and minimize confusion. He noted they have submitted an application to install the sign, and feel the proposed location is a good spot, considering the south and north developments are essentially part of one overall project in the OSMUD (Open Space Mixed Use Development) zoning district. Ms. Burke noted the OSMUD district has its own design guidelines and sign stipulations requiring real estate signs to be on the premises, and placement across the street would clearly be offsite. She added the Planning Board has the ability to waive the requirement under the bylaw. It was noted there currently is a small "New Homes" sign about 150 ft. in from East Main St., and Mr. Blute stated that if the Town allows his request, those would no longer be needed. Ms. Ritterbusch asked if the sign is proposed to be installed on the property with the historical home, and Mr. Blute stated yes, on the corner at the intersection with Legacy Farms North. Mr. Blute used a map of Legacy Farms to explain the location of the new homes, noting that signage as proposed would avoid confusion. Ms. Ritterbusch stated she understands the desire to avoid confusion, but does not like this type of signage near a historic home. Mr. D'Urso stated the two Pulte development parcels are not contiguous and he is not in favor of granting a waiver, and in this day and age prospective customers should not have any problems finding the new homes. Mr. Blute noted Pulte Homes noted they could uncover and keep the current sign, and Ms. Burke noted it would still need Planning Board permission. Mr. Paul noted moving the sign across the street would a "net zero" in his opinion and it would be better than having signs stapled to telephone poles. Mr. Ferrari asked how long the requirement has been in effect, and Ms. Burke stated for 7 years. Mr. Ferrari stated the Town has lived with this requirement all this time, and he is not looking to go back questioning the decision of a previous board to put the restriction in place. He noted if the Board grants a waiver, assuming Legacy Farms North will be under construction for another 6 or 7 years, the Town essentially will end up having a temporary sales sign for up to 14 years. The Board continued the discussion of Mr. Blute's request and the implications of granting a waiver. Ms. Burke noted that the previous board would not have included a waiver provision if it did not anticipate a need for it at some point during the life of the overall OSMUD development. Mr. D'Urso stated no one has mentioned input from Frankland Road residents on this issue, and based on that he supports the regulation as it stands. He moved to deny the request. Mr. Ferrari stated part of the issue is the size of the Legacy Farms North street sign which is not easy to spot, and perhaps a more visible sign would allow easier identification of the new homes while also indicating the location of the new bypass road. Mr. Blute stated Pulte Homes was not involved with the design and installation of the street sign, and Mr. Paul stated he is not in favor of a different style for the Legacy Farms neighborhoods. Ms. Burke stated Legacy Farms is not yet an accepted road and the Board is getting off topic. Mr. Nasrullah seconded the motion. Ms. Ritterbusch stated off premises real estate signs are not allowed in other parts of Town and granting the request would set a precedent. Robert Falcione, editor, HopNews, provided his opinion as a downtown business owner, and noted signage on East Main St. would be helpful from a business perspective and encourage people to use the Legacy Farms North shortcut. Chief Slaman stated Mr. Ferrari's idea of a larger Legacy Farms North street sign would be 4

interesting and beneficial from his perspective. Mr. DeYoung stated he agrees with Mr. Falcione that the temporary real estate sign would reduce confusion, stay true to the OSMUD design ideas, and it will not be a blight. Ms. Kramer noted she likes the idea of attractive identifying signs for the Legacy Farms developments eventually, also from a public safety perspective, but she cannot imagine the risk of confusion is that great and she does not a see a reason to change the bylaw to accommodate a private business. Ms. Karp stated she is willing to grant the waiver and review any future such requests on a case-by-case basis. Ms. Burke noted this concerns a regulation, not a bylaw. Mr. Nasrullah noted he agrees with Ms. Kramer and waiving the requirement may set a precedent. 3. Public Hearing - Minor Project Site Plan Review - 52 Wilson St. - A/Z Corporation Ms. Kramer moved to open and continue the public hearing upon the conclusion of the request of Pulte Homes for an off premise real estate sign for the Legacy Farms North villages, the motion was seconded and the Board voted unanimously in favor. 4. Legacy Farms North Villages - Pulte Homes - Request for Signage off Premises Continued Discussion Mr. Blute offered to work with someone on making the Legacy Farms North street sign more visible. Mr. Paul stated the Town in general has decided to make new development inclusive and is not in favor of variations on permanent street signs. The Board voted to deny Pulte Home's request 5 in favor (Kramer, Ritterbusch, Ferrari, Nasrullah, D'Urso) and 4 opposed (Paul, DeYoung, Karp, Kistner). Mr. Blute thanked the Board for its time. The Board took a 5 minute break. Ms. Kramer suggested making decisions on applications by making motions in the affirmative, making the outcome easier to understand. 5. Continued Public Hearing - Minor Project Site Plan Review - 52 Wilson St. - A/Z Corporation Ms. Kramer moved to reopen the public hearing, Mr. Ferrari seconded the motion, and the Board voted unanimously in favor. Glenn Stewart and Richard Drake, A/Z Corporation, applicant, and James Blackburn, Project Manager, Eversource Energy, appeared before the Board. Ms. Burke noted this is a minor site plan application for construction of a warehouse/machine shop accessory building at 52 Wilson St. She noted the application was submitted in May of this year but the public hearing process was delayed pending the outcome of a legal opinion by Town Counsel as to compliance with the zoning bylaw. She noted there were some discussions between Eversource and Town Counsel, and in July the decision was made in July that construction of the proposed building is allowed as an accessory use under site plan review. Mr. Blackburn provided background information on the facility which has been there for 47 years, and noted they propose to construct a new structure on site to increase and improve storage space for equipment and consumables in a more secure, temperature controlled indoor space. 5

Mr. Drake explained the proposal in more detail, noting it concerns the construction of a preengineered structure less than 5,000 s.f. in size, in compliance with the minimum setback requirements under the zoning bylaw in an area of the site that is currently empty. He described the floor plan which was revised from the original submission as a result of the Board of Health's requirements for hand wash and bathroom facilities. In response to a question of Mr. Kistner, Mr. Blackburn indicated the type of materials that will be stored in the new building, noting that currently some of these items are kept in boxes. Mr. DeYoung asked if the new building will be visible from the street or the Legacy Farms North development, and Mr. Blackburn stated people will not be able to see it from Wilson St. and he does not think it will be noticeable from the Legacy Farms walking trails. In response to a question of Mr. Paul regarding utilities, it was noted that everything is above ground with cable trays throughout the facility. The applicant described the building design in detail, including elevations and exterior finish. The Board discussed lighting, and Mr. Drake noted there will be wall packs above the door openings, with more conventional fixtures on the inside, all LID. Mr. Ferrari asked if there will be changes to landscaping or screening, and Mr. Blackburn stated they do not intend to change anything. Mr. Paul asked for clarification regarding the initial zoning concerns, and Ms. Burke explained that the use is not allowed in the Agricultural district, but that the facility is operating under an exemption issued by the Dept. of Public Utilities. She noted it was not clear at first if construction of this particular building was included in the existing DPU zoning exemption, but Town Counsel determined that there was no reason to go back to the DPU. In response to a question of Mr. D'Urso, Mr. Blackburn stated this particular proposal is not at all related to anything else Eversource is doing in Town, and is strictly a standalone project. Mr. D'Urso asked if it is still possible to locate the gas metering station planned for Elm St. at the Wilson St. campus instead, and Mr. Blackburn stated he personally believes it will not work from a spacing standpoint. In response to a question of Mr. Paul, Mr. Blackburn noted Air Products has operated the facility for 47 years and is currently contracted by Eversource who has owned it for the last 43 years. Mr. Ferrari asked about the process for approval, and Ms. Burke stated it is the same as for other site plan applications. Reference was made to Ms. Burke's memo to the Board, and the Board reviewed the draft conditions with the applicant. At the request of Ms. Karp, the applicant clarified existing utilities and noted that the application was accurate when originally filed but needed to be modified due to the Board of Health requirements. Mr. D'Urso suggested an additional condition requiring signoff from the Board of Health, and Ms. Burke stated the building permit process already addresses that requirement. Mr. D'Urso moved to find that the proposal concerns a minor site plan application, the application complies with the standards of site plan approval under the bylaw, and to approve the site plan with the following conditions: 1. The applicant shall be responsible for mitigating all construction related impacts, including erosion, siltation and dust control in a timely manner. (Site Plan Standard G) 2. The applicant shall regularly remove construction trash and debris from the site in accordance with good construction practice. No tree stumps, demolition material, trash or debris shall be burned or buried on the site. (Site Plan Standard G)

6

3. Mechanical equipment or other utility hardware on the roof, grounds or buildings shall be screened from view from the ground. (Site Plan Standard Q) 4. The Director of Municipal Inspections inspects Site Plans under construction for compliance with the approved Decision of Site Plan Review. If the Director of Municipal Inspections determines at any time before or during construction that a registered professional engineer or other such outside professional is required to assist with the inspections of the storm water management system or any other component of the Site Plan, the Applicant shall be responsible for the cost of those inspections. (All Site Plan Standards & § 210-137) 5. In accordance with § 210-138 of the Zoning Bylaw, the Applicant shall provide a performance guarantee in the amount of $3,000 to the Town prior to the commencement of construction pursuant to this Decision. The guarantee shall consist of a deposit of money or negotiable securities in a form selected by the Planning Board to guarantee that any unforeseen problems which arise, such as erosion and sedimentation and the correction of site lighting problems, are addressed. The funds will be held by the Town and returned to the Applicant upon completion of the project. (All Site Plan Standards & § 210-137) 6. Construction may occur only between the hours of 7:00 AM and 7:00 PM Monday through Friday and Saturdays between 8:00 AM and 4:00 PM pursuant to Chapter 141 Article 1 of the Town of Hopkinton General Bylaws. Mr. Paul seconded the motion and the Board voted unanimously in favor. Ms. Kramer moved to close the public hearing, Ms. Karp seconded the motion, and the Board voted unanimously in favor. 6. Box Mill Road (off Leonard St. Subdivision) - Rick Barbieri - Set Performance Guarantee Rick Barbieri, developer, appeared before the Board. Ms. Burke stated Mr. Barbieri submitted an estimate of remaining work, and the Board's inspecting engineer came back with a revised estimate in the amount of $97,560.00, which includes a 20% contingency. She noted the Board typically adds another $5,000.00 for legal fees for street acceptance resulting in a total amount of $102,560.00. Mr. Barbieri stated the amount is acceptable. Ms. Burke stated this particular development is somewhat unique as it concerns a subdivision through the approval-not-required (ANR) plan process, not involving lot releases from a conditional approval agreement, but requiring a performance guarantee to be established prior to the issuance of building permits. Mr. D'Urso asked about the number of homes to be built, and Mr. Barbieri stated there will be 3 in total and he plans to start as soon as the bond is posted. He noted the sewer stubs are in and the wells are installed. In response to a question of Mr. D'Urso, Mr. Barbieri stated he decided on private wells because the Town just replaced a 2 in. pipe with another 2 in. pipe which is inadequate. Mr. Kistner moved to establish a performance guarantee for Box Mill Road in the amount of $102,560.00, Ms. Kramer seconded the motion, and the Board voted unanimously in favor. Mr. Barbieri requested to discuss another issue related to Box Mill Road, and it was determined only the performance guarantee discussion was scheduled on tonight's agenda. The Board suggested that Mr. Barbieri follow up with Ms. Burke in the office. Mr. Kistner stepped off the Board at this time. 7. Saddle Hill Road - Scenic Road Violation - Saddle Hill Realty LLC - Discussion 7

John Parsons, and Victor Galvani, Saddle Hill Realty LLC, and David Anderson, Parsons Commercial Group, Project Manager, appeared before the Board. Ms. Burke noted a week and half ago she was informed by Bryan Besso, Board of Health Agent, about the removal of a section of stone wall and trees for site work at the Saddle Hill Road property owned by Saddle Hill Realty LLC. She noted she subsequently received an email from Mr. D'Urso with the same information, after which she contacted Mr. Galvani, issued an immediate Cease & Desist, and agreed to meet the developers on site the next day. She stated she met with Mr. Galvani and others on site the next day, looked at the area in question, measured the opening in the wall, and asked Mr. Galvani to appear before the Board tonight to discuss the violation. She stated it appeared that 23 ft. of stone wall was removed, resulting in a maximum fine of 23 x $300.00/linear foot for a total of $6,900.00. She stated they then walked along Saddle Hill Road and determined there was an existing opening further south with only low ground cover but no stones, and gave the developers permission to access the site there to continue the work as long as they restored the other opening to its original condition by noon the next day. She noted on the following Monday she met Mr. D'Urso on site after he informed her of another violation, which is the subject of some disagreement. Mr. Ferrari noted he walked the site more than a year ago when the property was evaluated for potential purchase as open space. but at this point there is a clear violation, amounting to 23 ft. of stone wall disturbance. He noted the Board will discuss the issue tonight, and perhaps a site walk will be helpful to take a look at conditions firsthand. Mr. D'Urso noted he feels there are 2 areas that were violated, with a third open to discussion based on input from neighbors who contacted him as well as one abutter who contacted Ms. Burke directly. He noted he does not understand how the work was allowed to start, without any notification of abutters, followed almost immediately with a scenic road violation and damage to the road. He noted people are concerned about the process and he asked for clarification as to what is expected as part of the ANR approval process. Ms. Burke noted abutter notification is not required under an ANR plan, and the lots in question have frontage on Saddle Hill Road. She noted the owners are therefore allowed to do site work and cut trees on their own property without prior approval as long as they are outside the wetlands buffer zone. Mr. D'Urso noted he feels the developers should not have been allowed to continue working for 8 days once the scenic road violation was identified. He stated he was also told that a tractor trailer brought onto the site would be removed, and that did not happen. Mr. Anderson referred to the section of stone wall removed without prior permission, and noted he believed it would be ok as long as they kept the stones for reuse. He noted he has done a lot of work in Hopkinton but has never been before the Board and apparently did not talk to the right people and ask the right questions. He noted when informed of the violation they immediately stopped the work and the wall was restored before noon the next day. He stated they clearly did the wrong thing, but truly value the scenic road character and take full responsibility. Ms. Kramer asked if any trees were cut as part of the violation, and Ms. Burke noted her inspection did not show any evidence of that. It was noted the work was prompted by the need for site testing, and Mr. Galvani stated they had all intentions to do this the right way and he was very disappointed to see the extent of the break in the wall. Ms. Karp asked if there any photos of the area from before this event, and Mr. Ferrari suggested using Google Earth. He suggested setting 8

up a site visit and continue the discussion at the next meeting. Mr. Nasrullah noted from his perspective this concerns an open violation and there is a process to be followed where the appropriate parties have a chance to take a look before anything else happens. Ms. Karp noted she is not questioning Ms. Burke's decision but feels the Board should have the opportunity to do some additional investigation before making further determinations. Josh Deisenroth, 74 Saddle Hill Rd. noted there are definitely 3 violations, 2 near Palomino Dr., already identified, the 3rd opening approved for access by the Principal Planner, and other locations where on numerous occasions the rocks were removed temporarily and put back later. Ms. Burke stated she disagrees and believes that is not what happened. Mr. D'Urso stated he disagrees on the process followed and does not understand how the developer is allowed to continue work with an additional violation without having to answer for the initial ones. He noted he feels Ms. Burke as an individual or employee of the Town did not have the authority to allow access through the opening further down. He noted only the Board as a whole has the authority to allow or disallow further work upon further investigation. Mr. Paul asked about the plan going forward, and Ms. Burke noted the developer has already submitted scenic road applications for 4 driveway openings. Mr. Paul stated he does not see a reason for asking the developer to stop work based on the available information. Ms. Karp noted it seems clear there was a violation, but she is not sure the applicants are continuing to violate. Mr. D'Urso noted only the Planning Board can make that decision. Ms. Kramer stated Saddle Hill Road residents have observed stones being moved, which would be a problem, and Mr. Anderson stated he is not aware of that happening. Mr. D'Urso noted the developers promised that the tractor trailer would be removed, and he has a photo of the northernmost stone wall section which shows that 14.9 ft. and 23 ft. sections were removed in that location. Ms. Burke noted she would like the record to show that she was never told the tractor trailer would be removed. Mr. D'Urso moved to require the proponents to stop all work until further investigation of the areas in question, Ms. Kramer seconded the motion. Mr. D'Urso noted he has pictures and a video to help make his point. Mr. Paul noted the developer will need approval for a total of 11 breaks in the wall, and asked about a complete plan. Mr. Parsons stated they need additional testing and the engineering has not been completed yet. Mr. Paul stated he feels the developers are going about this the wrong way, and asked about their decision to withdraw the subdivision plan, and Mr. Parsons noted it would have been very expensive and too time-consuming from a marketing perspective. Mr. Parson asked the Board to let them continue cutting trees as the issue is access to the property. The Board voted unanimously in favor of the motion. Mr. Kistner returned to the Board at this time. The Board scheduled a site walk for Saddle Hill Road on Saturday, September 9, 2017, at 9:00 A.M. to view the area of the scenic road violation discussed tonight. ADJOURNED: 10:15 P.M. Submitted by: Cobi Wallace, Permitting Assistant Approved ________________ Documents used at the Meeting:

9

  



   

Agenda for August 28, 2017 Planning Board meeting Memorandum from Jennifer Burke, Principal Planner, to Planning Board, dated August 23, 2017 re: Items on August 28, 2017 Planning Board Agenda Public Hearing Outline – Site Plan Review – 50-60 West Main St. – Golden Pond Expansion Project, Phase 3; Plans entitled “The Lofts at Golden Pond”, dated May 15, 2017 revised through July 17, 2017, prepared by J.D. Marquedant & Assoc., Inc.; letter to Town of Hopkinton Planning Board, Attn: Ms. Jennifer Burke, Principal Planner, from Philip F. Paradis, Jr. and Christopher Luppino, dated July 24, 2017, re: Site Plan Review Update for The Golden Pond Residential Care Corporation – Hopkinton, MA Public Hearing Outline – Site Plan Review – 52 Wilson Street; Letter to Jennifer Burke, Principal Planner from J. Raymond Miyares, Miyares and Harrington LLP, dated July 21, 2017 re: HOPCO Warehouse; Application for Site Plan Review, 52 Wilson St., Glenn Stewart, A/Z Corporation, for Air Products Warehouse Bldg; Memorandum from Bryan Besso, BOH Health Agent, to Cobi Wallace, Permitting Assistant, DLUPP, dated August 8, 2017, re: 52 Wilson St./Hopkinton LNG Corporation - Air Products Warehouse Maintenance Building - Minor Site Plan Review; Plans entitled Air Products Warehouse Building 52 Wilson Street, Hopkinton, Massachusetts, prepared by Loureiro Engineering, dated May 8 th, 2017, revised through August 28, 2017 Box Mill Road (off Leonard Street Subdivision) – Proposed Performance Guarantee, marked up by Bayassociates, Inc., dated 08/17/17 Legacy Farms North – Proposed “New Homes” Sign, & Locus Plan - Pulte Homes Draft Minutes – August 14, 2017 Missed Meeting Certificate – Frank D’Urso (July 24, 2017/Golden Pond Phase 3)

10