April 4, 2017 Mr. Alex Baylor AHERA / Environmental Inspector Environmental Safety Office 13306 Old Marlboro Pike Upper Marlboro, MD 20772 RE:

via email: [email protected]

Indoor Air Quality (IAQ) Assessment District Heights Elementary School 2200 County Road, District Heights, MD 20747 Tidewater Project No.: 1117-XXX

Dear Mr. Baylor: On March 30th, and March 31st, 2017, Tidewater, Inc. (Tidewater), represented by Project Manager Mr. Skanda Abeyesekere MS, CIH, CSP, CHMM, performed an Indoor Air Quality (IAQ) assessment at District Heights Elementary School located at 2200 Country Road in District Heights, Maryland. Tidewater performed the IAQ testing at the request of Prince Georges’ County Public Schools (PGCPS) representative, Mr. Alex Baylor, to establish baseline IAQ measurements in select occupied areas of the school. The scope of work for the IAQ assessment included: •

Visual inspection for evidence of potential indoor air quality problems (including suspect microbial growth, water damage, chemical use/storage, drain traps, sources of allergens/contaminants, etc.) that might contribute to indoor air quality problems;

•

Comfort parameter air testing in select occupied areas: direct read measurements for temperature (T), relative humidity (RH), carbon monoxide (CO), and carbon dioxide (CO2) for comparison with guidelines established by the American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) Standard 62.1–2016, Ventilation for Acceptable Indoor Air Quality, and the Indoor Air Quality Association (IAQA);

•

Air Sampling for bioaerosols in select occupied areas for airborne fungal spores using Allergenco-D cassettes affixed to a Buck BioAireTM Model B520 Bioaerosol Sampling Pump for total airborne fungal spore analysis; and

•

Air sampling for Total (nuisance) dust in select occupied areas using PVC PW 37mm cassettes with pre-weighed filters, attached to a low-volume air sampling pumps.

Visual Observations Tidewater’s assessment included a visual inspection of the Main Office area, Vice Principal’s Office, Classroom 4, Classroom 17, Classroom K-2, Classroom 10, Storage Room, Media Room, Classroom 7B, and Classroom M-18. The results of Tidewater’s visual inspection are as follows: •

In general, the Main Office area, Vice Principal’s office, Classroom 4, Classroom 17, Classroom K-2, Classroom 10, Media Room, Classroom 7B, and Classroom M-18 appeared to be relatively clean, which provides evidence of good housekeeping practices in the building; 6625 Selnick Drive, Suite A, Elkridge, MD 21075 (410) 540-8700 p (410) 997-8713 f www.tideh2o.net

•

The air supply/return diffusers observed in the Main Office area, common areas, the classrooms and other areas appeared to be generally clean;

•

Tidewater did not observe any standing water or active water intrusion during the visual inspection. However, water-stained ceiling tiles were observed in the main office room, storage room, and classroom 4;

•

Tidewater detected a food odor emanating from classroom K-2 which was conducted around 9:00am; and

•

The office areas are serviced by ceiling mounted air supply vents and return air grills. The HVAC systems in some office areas were in operation at the time of the inspection, while the HVAC systems in other office areas were shut off at the time of the inspection. The air in Classroom 7B and Classroom K-2 was stagnant and the general air circulation was poor.

Comfort Parameter Air Testing During the assessment, Tidewater recorded temperature, relative humidity, carbon dioxide (CO2), and carbon monoxide (CO) measurements in select areas of District Heights Elementary School using a Metrosonics Indoor Air Quality instrument (Model Number AQ-5000, Serial Number 2157.) Tidewater recorded these measurements after allowing the device to become acclimated to the ambient temperature and relative humidity for five (5) minutes. Tidewater programmed the Metrosonics Indoor Air Quality (IAQ) instrument to sample every 30 seconds for a period of 10 minutes at each location, and the average concentration of each comfort parameter was recorded. Tidewater also obtained a background sample from outside the main entrance to the school building for comparison. The results of the IAQ comfort parameter monitoring are provided in Table 1 below. Table 1: March 30, 2017 Indoor Air Quality Comfort Parameters District Heights Elementary School Location

Temperature (°F)

Carbon Dioxide (ppm)

Relative Humidity (%)

Carbon Monoxide (ppm)

Main Office

73.8

910

28.8

0.0

Vice Principal’s Office

74.9

710

28.2

0.0

Classroom 17

76.0

696

27.0

0.0

Storage Room

76.9

687

31.9

0.0

Classroom K-2

78.5

1,287

30.8

0.0

Classroom 10

77.1

1,892

35.0

0.0

Media Room

77.6

533

25.6

0.0

Classroom 7B

78.0

2,200

36.9

0.0

Page 2 of 7

Table 1: March 30, 2017 Indoor Air Quality Comfort Parameters District Heights Elementary School Location

Temperature (°F)

Carbon Dioxide (ppm)

Relative Humidity (%)

Carbon Monoxide (ppm)

Classroom 4

77.7

2,346

35.8

0.0

Classroom M-18

69.8

448

27.5

0.0

Background

53.6

466

39.5

0.0

According to the American Society for Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) guidelines Standard 62.1 – 2016, the temperature range in summer months should be maintained between 73°F and 79°F for maximum occupant comfort. The ASHRAE guideline for temperature for winter months is between 68.0°F and 74.5°F. The indoor temperature levels within the areas sampled ranged between 73.8°F and 78.0°F. The background temperature level outside the building on the day of the survey was 53.6°F. The majority of the temperature levels recorded within the select indoor locations were within temperature levels typically found during spring transitional months. The temperature levels in the media room, classrooms 4, 10, 7B, and K-2 marginally exceeded the limit. Per the same guideline, a maximum recommended relative humidity level of 65.0% is recommended to reduce the likelihood of condensation on cold surfaces. Relative humidity levels within the indoor locations ranged between 25.6% and 36.9%. The background relative humidity level was 39.5% outside the building. The relative humidity readings in the indoor locations were below the ASHRAE recommended maximum relative humidity level of 65%. ASHRAE Standard 62.1 – 2016 recommends that indoor CO2 levels not exceed 700 ppm above the outdoor background CO2 level. The CO2 levels in the indoor locations ranged between 448 ppm to 2,346 ppm. The background CO2 level outside the building was 466 ppm. The CO2 levels within Classrooms K-2, 10, 7B, and 4 exceeded 700 ppm above the outdoor background CO2 level (466), which is the maximum ASHRAE recommended guideline for CO2 in indoor environments. The elevated CO2 levels in these office areas indicate inadequate air supply to these office areas. There were over 20 students in each of these classrooms during the inspection. Tidewater did not detect CO in all indoor areas assessed, and therefore were below the maximum guideline of 9 ppm recommended by the Indoor Air Quality Association (IAQA) for CO in occupied indoor environments. Spore Trap Bioaerosol Sampling One March 30, 2017, Tidewater collected a total of 11 spore trap air samples using Allegenco-D cassettes to characterize potential airborne fungal spores within the school building. Ten (10) indoor samples were collected from select areas of the building and one (1) background sample (Sample # A-O-11) was collected outside the building for comparative purposes.

Page 3 of 7

Tidewater obtained these samples using Allergenco-D cassettes to characterize potential airborne fungal spores in the assessed areas. Air samples were collected for total fungal spores using the pump from a Buck BioAire™ Bioaerosol Sampling Pump (Pump Model Number B520 and Serial Number B151491) calibrated to a flow rate of 15.0 Liters per minute. Each sample was run for a period of five (5) minutes at each location to collect a total sample volume of 75 liters of air. Once collected, the samples were transported to EMSL Analytical Laboratory (EMSL) located in Beltsville, Maryland for analysis with a same day turnaround time. The samples were transported following rigorous chain-of-custody guidelines to ensure proper handling and delivery of the samples. EMSL is accredited in the American Industrial Hygiene Association (AIHA) Environmental Microbiology Laboratory Accreditation Program (EMLAP) and is a successful participant in AIHA’s Environmental Microbiology Proficiency Analytical Testing (EMPAT) program (Laboratory Number 102891.) The samples were analyzed via light microscopy at the standardized magnification of 600X. This technique does not allow for the differentiation between Aspergillus and Penicillium spores because they are morphologically identical. Additionally, the technique does not allow for cultivation, or the identification of spores to the species level, except in a few cases. The summary of the results for the spore trap sampling are provided in Table 2 below. The laboratory analytical results, including speciation and chain of custody forms for the spore trap samples are included as Attachment A. Table 2: March 30, 2017 Spore Trap Sampling Results District Heights Elementary School Sample Number

Sample Location

Sample Volume (L)

Total Fungi Concentration (Counts/m3)

A-O-1

Main Office

75

230

A-O-2

Vice Principal’s Office

75

240

A-O-3

Classroom 17

75

130

A-O-4

Storage Room

75

600

A-O-5

Classroom K-2

75

240

A-O-6

Classroom 10

75

450

A-O-7

Media Room

75

530

A-O-8

Classroom 7B

75

340

A-O-9

Classroom 4

75

1,250

A-O-10

Classroom M-18

75

200

A-O-11

Background (Ambient)

75

990

Page 4 of 7

There are no universally accepted federal or State of Maryland standards for acceptable airborne concentrations of bioaerosols in an indoor occupational environment. In general, airborne concentrations indoors should be less than that found in the outdoor air, with similar species composition. Indoor spore counts significantly greater than those outdoors, or the presence of large numbers of different types of spores indoors that are not found outdoors, may indicate contamination and potential indoor air quality problems. The total mold spore counts for the samples collected inside the affected classrooms ranged from 130 to 1,250 spores per cubic meter (spores/m3). The total mold spore concentration in the outdoors (background) sample was 990. The mold spore concentration in the majority of indoor samples were below the outdoors (background) sample total count of 990 spores/m3. The total mold spore concentration in Classroom 4 was 1,250 and was marginally above the background concentration. No significant concentrations of individual fungal species were identified in the assessed indoor area samples. These results do not suggest the presence of a significant indoor source of fungal contamination that would adversely affect indoor air quality within the sampled areas. Ambient weather conditions were noted to be approximately 53.60 Fahrenheit, mild precipitation, and gloomy conditions. Particulate Sampling for Total (Nuisance) Dust Particulate sampling for total dust was conducted in select areas of the District Heights Elementary School building. The sampling was conducted using low-volume air pumps to draw air through sample cassettes containing filters that would collect dust, fibers and other particulates. The low-volume pumps were calibrated at 2.0 liters per minute using a calibration device. The sampling media used were cassettes with 37 mm mixed cellulose ester (MCE) preweighed filters, open faced (0.8 micrometer pore size preloaded in three-piece cassette.) Tidewater shipped the samples to SGS Galson Laboratories located in East Syracuse, New York with a 24-hour turnaround time following rigorous chain-of-custody guidelines to ensure proper handling and delivery of the samples. SGS Galson Laboratories is accredited in the American Industrial Hygiene Association (AIHA) Industrial Hygiene Laboratory Accreditation Program (IHLAP) and is a successful participant in AIHA’s Industrial Hygiene Proficiency Analytical Testing (IHPAT) program (AIHA-LAP #100324; and DOH ELAP #11626.) The samples were analyzed using the Total Dust Analysis (Gravimetric) via NIOSH Method 0500, Issue 2, 8/15/94. The total (nuisance) dust results are summarized on Table 3. The laboratory analytical results are included in Appendix B.

Page 5 of 7

Table 3: March 31, 2017 Respirable Dust Sampling District Heights Elementary School Sample Number

Building Location

Dust concentration (mg/m3)

Z2010955

Main Office

<0.38

Z2010933

Assistant Principal’s Office

<0.42

Z2010958

Classroom 17

<0.42

Z2010930

Classroom 10

<0.42

Z2010969

Classroom K-2

<0.42

Z2010973

Media Room

<0.42

Z2010943

Classroom 7B

<0.42

Z2010954

Classroom 4

<0.42

The laboratory results indicate that the total particulate levels in all of the samples collected were below the OSHA 8-hour Permissible Exposure Limit (PEL) of 15 mg/m3 for total (nuisance) dust levels in office environments. Conclusions Based on this IAQ assessment, Tidewater offers the following conclusions: •

Tidewater’s visual inspection of the select occupied areas of the District Heights Elementary School did not reveal any visible evidence of ongoing water intrusion on the walls, floors or ceiling in any of the office areas inspected. However, stained ceiling tiles, indicating signs of past water intrusion were observed in the Main Office, Storage Room, and Classroom 4;

•

The average temperature readings in the select indoor areas ranged between 73.8°F and 78.0°F. Majority of these occupied spaces had temperature levels within the typical temperature level recommended by ASHRAE for spring months. However, the temperature levels in the media room, classrooms 4, 10, 7B, and K-2 marginally exceeded the temperature range typically observed for spring transitional months;

•

The average relative humidity levels in the select indoor areas ranged between 25.6% and 36.9%. These temperature levels were below the ASHRAE recommended maximum relative humidity level of 65%;

•

The CO2 levels within Classrooms K-2, 10, 7B, and 4 exceeded 700 ppm above the outdoor background CO2 level (466), which is the maximum ASHRAE recommended guideline for CO2 in indoor environments. The elevated CO2 levels indicate inadequate air supply to these classrooms;

•

Tidewater did not detect CO in all indoor locations assessed; Page 6 of 7

•

The spore trap air sample (non-viable) results do not indicate the presence of a significant indoor source of fungal contamination that would adversely affect indoor air quality within the assessed areas of the building; an

•

Particulate sampling for total (nuisance) dust analytical results are all of the samples collected were below the OSHA 8-hour Permissible Exposure Limit (PEL) of 15 mg/m3 for total (nuisance) dust.

Recommendations Based on these findings, Tidewater recommends the following steps: •

Investigate above the water stained ceiling tiles in the main office, storage room and classroom 4 for any ongoing water leaks. If any leaks are detected, repair them immediately. Replace all water-stained ceiling tiles in the main office, storage room and classroom 4;

•

Ensure the Heating Ventilation and Air Conditioning (HVAC) System supplying air to the classrooms and offices is properly maintained and balanced per the design requirements in order to ensure adequate ventilation throughout the building;

•

Adjust the HVAC system in order to increase the number of air exchanges to Classroom 4, Classroom K-2, Classroom 10, Classroom 7B and the Media Room. This will help lower the overall CO2 levels to a standard below 700ppm above the background levels.

Qualifications Tidewater has endeavored to investigate existing conditions in select areas of the school building at the District Heights Elementary School located at 2200 Country Road, District Heights, Maryland as they pertain to indoor air quality. Our conclusions and recommendations are based on the observations made on the day of our assessment, laboratory data from the time of the assessment, and information provided by both our Client and the area occupants. Actual conditions vary from day to day throughout the year. Tidewater appreciates the opportunity to provide consulting services for Prince Georges County Public Schools. Please contact us should any questions arise concerning this report or if we may be of further assistance. Sincerely, Tidewater, Inc.

Skanda Abeyesekere, MS, CIH, CSP, CHMM Project Manager

Jonathan N. Schatz, MS, CES, CEI Manager, IH Services

SA/JNS Attachments:

Attachment A – Laboratory Results for Non-Viable Spore Trap Sampling Attachment B – Laboratory Results for Total Dust and Particulates

Page 7 of 7

Attachment A Laboratory Results for Non-Viable Spore Trap Sampling

EMSL Analytical, Inc.

Order ID: Customer ID: Customer PO: Project ID:

10768 Baltimore Avenue Beltsville, MD 20705 Phone/Fax: (301) 937-5700 / (301) 937-5701 http://www.EMSL.com / [email protected] Phone: Fax: Collected: Received: Analyzed:

Attn:

Skanda Abeyeskere Tidewater, Inc. 6625 Selnick Drive Suite A Elkridge, MD 21075

Proj:

DISTRICT HEIGHTS E3

191703581 TIDE50

(410) 997-4458 (410) 997-8713 03/30/2017 03/30/2017 03/31/2017

Test Report: Allergenco-D(™) Analysis of Fungal Spores & Particulates by Optical Microscopy (Methods EMSL 05-TP-003, ASTM D7391) Lab Sample Number: Client Sample ID: Volume (L): Sample Location:

Spore Types Alternaria Ascospores Aspergillus/Penicillium Basidiospores Bipolaris++ Chaetomium Cladosporium Curvularia Epicoccum Fusarium Ganoderma Myxomycetes++ Pithomyces Rust Scopulariopsis Stachybotrys Torula Ulocladium Unidentifiable Spores Zygomycetes Dicyma Total Fungi Hyphal Fragment Insect Fragment Pollen Analyt. Sensitivity 600x Analyt. Sensitivity 300x Skin Fragments (1-4) Fibrous Particulate (1-4) Background (1-5)

191703581-0001 A-0-1 75 MAIN OFFICE

191703581-0002 A-0-2 75 VICE PRINC OFFICE

191703581-0003 A-0-3 75 CLASSROOM 17

Raw Count

Count/m³

% of Total

Raw Count

Count/m³

% of Total

Raw Count

Count/m³

% of Total

-

-

-

-

-

-

-

-

-

-

-

-

1

40

16.7

-

-

-

2

90

39.1

-

-

-

-

-

-

-

-

-

3

100

41.7

2

90

69.2

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

2

90

39.1

2

90

37.5

1

40

30.8

1*

10*

4.3

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

1

40

17.4

1*

10*

4.2

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

6

230

100

7

240

100

3

130

100

1

40

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

1*

10*

-

-

44

-

-

44

-

-

44

-

-

13*

-

-

13*

-

-

13*

-

-

4

-

-

2

-

-

2

-

-

1

-

-

1

-

-

1

-

-

2

-

-

1

-

-

1

-

Bipolaris++ = Bipolaris/Drechslera/Exserohilum Myxomycetes++ = Myxomycetes/Periconia/Smut No discernable field blank was submitted with this group of samples.

Stefanie Schneider, Microbiology Lab Manager or Other Approved Signatory

High levels of background particulate can obscure spores and other particulates leading to underestimation. Background levels of 5 indicate an overloading of background particulates, prohibiting accurate detection and quantification. Present = Spores detected on overloaded samples. Results are not blank corrected unless otherwise noted. The detection limit is equal to one fungal spore, structure, pollen, fiber particle or insect fragment. "*" Denotes particles found at 300X. *-* denotes not detected. EMSL maintains liability limited to cost of analysis. This report relates only to the samples reported above and may not be reproduced, except in full, without written approval by EMSL. EMSL bears no responsibility for sample collection activities or analytical method limitations. Interpretation and use of test results are the responsibility of the client. Samples received in good condition unless otherwise noted. Samples analyzed by EMSL Analytical, Inc. Beltsville, MD AIHA-LAP, LLC--EMLAP Lab 102891

Initial report from: 03/31/2017 10:37:50 For Information on the fungi listed in this report please visit the Resources section at www.emsl.com

Test Report SPVER3-7.30.4 Printed: 3/31/2017 10:37:50AM

Page 1 of 4

EMSL Analytical, Inc.

Order ID: Customer ID: Customer PO: Project ID:

10768 Baltimore Avenue Beltsville, MD 20705 Phone/Fax: (301) 937-5700 / (301) 937-5701 http://www.EMSL.com / [email protected] Phone: Fax: Collected: Received: Analyzed:

Attn:

Skanda Abeyeskere Tidewater, Inc. 6625 Selnick Drive Suite A Elkridge, MD 21075

Proj:

DISTRICT HEIGHTS E3

191703581 TIDE50

(410) 997-4458 (410) 997-8713 03/30/2017 03/30/2017 03/31/2017

Test Report: Allergenco-D(™) Analysis of Fungal Spores & Particulates by Optical Microscopy (Methods EMSL 05-TP-003, ASTM D7391) Lab Sample Number: Client Sample ID: Volume (L): Sample Location:

Spore Types Alternaria Ascospores Aspergillus/Penicillium Basidiospores Bipolaris++ Chaetomium Cladosporium Curvularia Epicoccum Fusarium Ganoderma Myxomycetes++ Pithomyces Rust Scopulariopsis Stachybotrys Torula Ulocladium Unidentifiable Spores Zygomycetes Dicyma Total Fungi Hyphal Fragment Insect Fragment Pollen Analyt. Sensitivity 600x Analyt. Sensitivity 300x Skin Fragments (1-4) Fibrous Particulate (1-4) Background (1-5)

191703581-0004 A-0-4 75 STORAGE ROOM

191703581-0005 A-0-5 75 K-2 CLASSROOM

191703581-0006 A-0-6 75 ROOM 10

Raw Count

Count/m³

% of Total

Raw Count

Count/m³

% of Total

Raw Count

Count/m³

-

-

-

-

-

-

-

-

% of Total -

-

-

-

-

-

-

1*

10*

2.2

9

400

66.7

-

-

-

1

40

8.9

4

200

33.3

3

100

41.7

2

90

20

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

2

90

37.5

5

200

44.4

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

1

40

16.7

1

40

8.9

-

-

-

1*

10*

4.2

1

40

8.9

-

-

-

-

-

-

2*

30*

6.7

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

13

600

100

7

240

100

13

450

100

-

-

-

-

-

-

1

40

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

44

-

-

44

-

-

44

-

-

13*

-

-

13*

-

-

13*

-

-

3

-

-

4

-

-

4

-

-

1

-

-

1

-

-

1

-

-

1

-

-

1

-

-

2

-

Bipolaris++ = Bipolaris/Drechslera/Exserohilum Myxomycetes++ = Myxomycetes/Periconia/Smut No discernable field blank was submitted with this group of samples.

Stefanie Schneider, Microbiology Lab Manager or Other Approved Signatory

High levels of background particulate can obscure spores and other particulates leading to underestimation. Background levels of 5 indicate an overloading of background particulates, prohibiting accurate detection and quantification. Present = Spores detected on overloaded samples. Results are not blank corrected unless otherwise noted. The detection limit is equal to one fungal spore, structure, pollen, fiber particle or insect fragment. "*" Denotes particles found at 300X. *-* denotes not detected. EMSL maintains liability limited to cost of analysis. This report relates only to the samples reported above and may not be reproduced, except in full, without written approval by EMSL. EMSL bears no responsibility for sample collection activities or analytical method limitations. Interpretation and use of test results are the responsibility of the client. Samples received in good condition unless otherwise noted. Samples analyzed by EMSL Analytical, Inc. Beltsville, MD AIHA-LAP, LLC--EMLAP Lab 102891

Initial report from: 03/31/2017 10:37:50 For Information on the fungi listed in this report please visit the Resources section at www.emsl.com

Test Report SPVER3-7.30.4 Printed: 3/31/2017 10:37:50AM

Page 2 of 4

EMSL Analytical, Inc.

Order ID: Customer ID: Customer PO: Project ID:

10768 Baltimore Avenue Beltsville, MD 20705 Phone/Fax: (301) 937-5700 / (301) 937-5701 http://www.EMSL.com / [email protected] Phone: Fax: Collected: Received: Analyzed:

Attn:

Skanda Abeyeskere Tidewater, Inc. 6625 Selnick Drive Suite A Elkridge, MD 21075

Proj:

DISTRICT HEIGHTS E3

191703581 TIDE50

(410) 997-4458 (410) 997-8713 03/30/2017 03/30/2017 03/31/2017

Test Report: Allergenco-D(™) Analysis of Fungal Spores & Particulates by Optical Microscopy (Methods EMSL 05-TP-003, ASTM D7391) Lab Sample Number: Client Sample ID: Volume (L): Sample Location:

Spore Types Alternaria Ascospores Aspergillus/Penicillium Basidiospores Bipolaris++ Chaetomium Cladosporium Curvularia Epicoccum Fusarium Ganoderma Myxomycetes++ Pithomyces Rust Scopulariopsis Stachybotrys Torula Ulocladium Unidentifiable Spores Zygomycetes Dicyma Total Fungi Hyphal Fragment Insect Fragment Pollen Analyt. Sensitivity 600x Analyt. Sensitivity 300x Skin Fragments (1-4) Fibrous Particulate (1-4) Background (1-5)

191703581-0007 A-0-7 75 MEDIA ROOM

191703581-0008 A-0-8 75 CLASSROOM 7-B

191703581-0009 A-0-9 75 CLASSROOM-4

Raw Count

Count/m³

% of Total

Raw Count

Count/m³

% of Total

Raw Count

Count/m³

% of Total

-

-

-

1*

10*

2.9

1

40

3.2

2

90

17

-

-

-

-

-

-

-

-

-

-

-

-

3

100

8

9

400

75.5

1

40

11.8

-

-

-

-

-

-

-

-

-

1

40

3.2

-

-

-

-

-

-

-

-

-

1

40

7.5

5*

70*

20.6

12

530

42.4

-

-

-

1*

10*

2.9

1*

10*

0.8

-

-

-

-

-

-

1

40

3.2

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

4

200

58.8

10

440

35.2

-

-

-

1*

10*

2.9

1

40

3.2

-

-

-

-

-

-

1*

10*

0.8

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

12

530

100

13

340

100

31

1250

100

-

-

-

-

-

-

4

200

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

44

-

-

44

-

-

44

-

-

13*

-

-

13*

-

-

13*

-

-

2

-

-

4

-

-

4

-

-

1

-

-

1

-

-

1

-

-

1

-

-

2

-

-

2

-

Bipolaris++ = Bipolaris/Drechslera/Exserohilum Myxomycetes++ = Myxomycetes/Periconia/Smut No discernable field blank was submitted with this group of samples.

Stefanie Schneider, Microbiology Lab Manager or Other Approved Signatory

High levels of background particulate can obscure spores and other particulates leading to underestimation. Background levels of 5 indicate an overloading of background particulates, prohibiting accurate detection and quantification. Present = Spores detected on overloaded samples. Results are not blank corrected unless otherwise noted. The detection limit is equal to one fungal spore, structure, pollen, fiber particle or insect fragment. "*" Denotes particles found at 300X. *-* denotes not detected. EMSL maintains liability limited to cost of analysis. This report relates only to the samples reported above and may not be reproduced, except in full, without written approval by EMSL. EMSL bears no responsibility for sample collection activities or analytical method limitations. Interpretation and use of test results are the responsibility of the client. Samples received in good condition unless otherwise noted. Samples analyzed by EMSL Analytical, Inc. Beltsville, MD AIHA-LAP, LLC--EMLAP Lab 102891

Initial report from: 03/31/2017 10:37:50 For Information on the fungi listed in this report please visit the Resources section at www.emsl.com

Test Report SPVER3-7.30.4 Printed: 3/31/2017 10:37:50AM

Page 3 of 4

EMSL Analytical, Inc.

Order ID: Customer ID: Customer PO: Project ID:

10768 Baltimore Avenue Beltsville, MD 20705 Phone/Fax: (301) 937-5700 / (301) 937-5701 http://www.EMSL.com / [email protected] Phone: Fax: Collected: Received: Analyzed:

Attn:

Skanda Abeyeskere Tidewater, Inc. 6625 Selnick Drive Suite A Elkridge, MD 21075

Proj:

DISTRICT HEIGHTS E3

191703581 TIDE50

(410) 997-4458 (410) 997-8713 03/30/2017 03/30/2017 03/31/2017

Test Report: Allergenco-D(™) Analysis of Fungal Spores & Particulates by Optical Microscopy (Methods EMSL 05-TP-003, ASTM D7391) Lab Sample Number: Client Sample ID: Volume (L): Sample Location:

Spore Types Alternaria Ascospores Aspergillus/Penicillium Basidiospores Bipolaris++ Chaetomium Cladosporium Curvularia Epicoccum Fusarium Ganoderma Myxomycetes++ Pithomyces Rust Scopulariopsis Stachybotrys Torula Ulocladium Unidentifiable Spores Zygomycetes Dicyma Total Fungi Hyphal Fragment Insect Fragment Pollen Analyt. Sensitivity 600x Analyt. Sensitivity 300x Skin Fragments (1-4) Fibrous Particulate (1-4) Background (1-5)

191703581-0010 A-0-10 75 M-18

191703581-0011 A-0-11 75 BACKGROUND

191703581-9901 Dummy Dummy Dummy

Raw Count

Count/m³

% of Total

Raw Count

Count/m³

% of Total

-

-

-

-

-

-

1*

10*

1

-

-

-

2*

30*

15

1

40

4

-

-

-

-

-

-

9

400

40.4

-

-

-

1

40

20

5

200

20.2

-

-

-

1*

10*

5

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

6

300

30.3

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

1

40

4

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

1

40

20

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

6*

80*

40

-

-

-

-

-

-

11

200

100

23

990

100

-

-

-

1

40

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

2

90

-

-

-

-

-

44

-

-

44

-

-

-

-

-

13*

-

-

13*

-

-

-

-

-

3

-

-

1

-

-

-

-

-

1

-

-

1

-

-

-

-

-

1

-

-

2

-

-

-

-

Bipolaris++ = Bipolaris/Drechslera/Exserohilum Myxomycetes++ = Myxomycetes/Periconia/Smut No discernable field blank was submitted with this group of samples.

Stefanie Schneider, Microbiology Lab Manager or Other Approved Signatory

High levels of background particulate can obscure spores and other particulates leading to underestimation. Background levels of 5 indicate an overloading of background particulates, prohibiting accurate detection and quantification. Present = Spores detected on overloaded samples. Results are not blank corrected unless otherwise noted. The detection limit is equal to one fungal spore, structure, pollen, fiber particle or insect fragment. "*" Denotes particles found at 300X. *-* denotes not detected. EMSL maintains liability limited to cost of analysis. This report relates only to the samples reported above and may not be reproduced, except in full, without written approval by EMSL. EMSL bears no responsibility for sample collection activities or analytical method limitations. Interpretation and use of test results are the responsibility of the client. Samples received in good condition unless otherwise noted. Samples analyzed by EMSL Analytical, Inc. Beltsville, MD AIHA-LAP, LLC--EMLAP Lab 102891

Initial report from: 03/31/2017 10:37:50 For Information on the fungi listed in this report please visit the Resources section at www.emsl.com

Test Report SPVER3-7.30.4 Printed: 3/31/2017 10:37:50AM

Page 4 of 4

OrderID: 191703581

Page 1 Of

2

OrderID: 191703581

Page 2 Of

2

Attachment B Laboratory Results for Nuisance Dust and Particulates Analysis