Pipeline Association for Public Awareness

Recommended Minimum Evacuation Distances For

Natural Gas Pipeline Leaks and Ruptures (Not applicable for Butane, Propane, or other Hazardous Liquids)

Pressure (psig)

Pipeline Size (inches)

100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000 2100 2200

4 91 129 158 182 204 223 241 258 274 288 302 316 329 341 353 365 376 387 398 408 418 428

6 137 193 237 274 306 335 362 387 410 433 454 474 493 512 530 547 564 580 596 612 627 642

8 182 258 316 365 408 447 483 516 547 577 605 632 658 682 706 730 752 774 795 816 836 856

10 228 322 395 456 510 558 603 645 684 721 756 790 822 853 883 912 940 967 994 1020 1045 1069

12 274 387 474 547 612 670 724 774 821 865 907 948 986 1024 1060 1094 1128 1161 1193 1224 1254 1283

16 365 516 632 730 816 894 965 1032 1094 1154 1210 1264 1315 1365 1413 1459 1504 1548 1590 1631 1672 1711

20 456 645 790 912 1020 1117 1206 1290 1368 1442 1512 1580 1644 1706 1766 1824 1880 1935 1988 2039 2090 2139

22 502 709 869 1003 1122 1229 1327 1419 1505 1586 1664 1738 1809 1877 1943 2006 2068 2128 2186 2243 2299 2353

24 547 774 948 1094 1224 1340 1448 1548 1642 1730 1815 1896 1973 2047 2119 2189 2256 2322 2385 2447 2508 2567

30 684 967 1185 1368 1529 1675 1810 1935 2052 2163 2269 2369 2466 2559 2649 2736 2820 2902 2981 3059 3134 3208

36 821 1161 1422 1642 1835 2011 2172 2322 2462 2596 2722 2843 2959 3071 3179 3283 3384 3482 3578 3671 3761 3850

42 958 1354 1659 1915 2141 2346 2534 2709 2873 3028 3176 3317 3453 3583 3709 3830 3948 4063 4174 4283 4388 4492

Table 1 - Evacuation Distance in Feet The applicable leak or rupture condition is that of a sustained trench fire fueled by non-toxic natural gas escaping from two full bore pipe ends. Blast overpressure is not addressed. The distances shown in Table 1 are intended to provide protection from burn injury and correspond to a thermal heat flux exposure level of 450 Btu/hr ft2. This is the accepted limit of heat exposure for unprotected outdoor areas where people congregate; as established by the US Department of Housing & Development Code 24CFR51, Subpart C, Siting of HUD Assisted Projects Near Hazardous Operations Handling Conventional Fuels or Chemicals of an Explosive or Flammable Nature. The formula used to calculate distance was taken from the Gas Research Institute Report GRI-00/0189, A Model for Sizing High Consequence Areas Associated with Natural Gas Pipelines, 2001, prepared by C-FER Technologies. That model does not take into account wind or other factors which may greatly influence specific conditions. Users are advised that the distances shown in Table 1 are considered to be “general information” only and are not intended to replace a site specific risk analysis. The Pipeline Association for Public Awareness makes no warranty with respect to the usefulness of this information and assumes no liability for any and all damages resulting from its use. Anyone using this information does so at their own risk.