Default Total Hydrocarbon Leaker Emission Factors

Equipment components Emission factor (scf total hydrocarbon/hour/component) If you survey using Method 21 as specified in § 98.234(a)(2)(i) If you survey using Method 21 as specified in § 98.234(a)(2)(ii) If you survey using any of the methods in § 98.234(a)(1), (3), or (5) Leaker Emission Factors—Onshore Natural Gas Processing, Onshore Natural Gas Transmission Compression—Compressor Components, Gas Service Valve 1 14.84 9.51 24.2 Connector 5.59 3.58 9.13 Open-Ended Line 17.27 11.07 28.2 Pressure Relief Valve 39.66 25.42 64.8 Meter 19.33 12.39 31.6 Other 2 4.1 2.63 6.70 Leaker Emission Factors—Onshore Natural Gas Processing, Onshore Natural Gas Transmission Compression—Non-Compressor Components, Gas Service Valve 1 6.42 4.12 10.5 Connector 5.71 3.66 9.3 Open-Ended Line 11.27 7.22 18.4 Pressure Relief Valve 2.01 1.29 3.28 Meter 2.93 1.88 4.79 Other 2 4.1 2.63 6.70 Leaker Emission Factors—Underground Natural Gas Storage—Storage Station, Gas Service Valve 1 14.84 9.51 24.2 Connector (other) 5.59 3.58 9.13 Open-Ended Line 17.27 11.07 28.2 Pressure Relief Valve 39.66 25.42 64.8 Meter and Instrument 19.33 12.39 31.6 Other 2 4.1 2.63 6.70 Leaker Emission Factors—Underground Natural Gas Storage—Storage Wellheads, Gas Service Valve 1 4.5 3.2 7.35 Connector (other than flanges) 1.2 0.7 1.96 Flange 3.8 2.0 6.21 Open-Ended Line 2.5 1.7 4.08 Pressure Relief Valve 4.1 2.5 6.70 Other 2 4.1 2.5 6.70 1 Valves include control valves, block valves and regulator valves. 2 Other includes any potential equipment leak emission point in gas service that is not specifically listed in this table, as specified in § 98.232(d)(7) for onshore natural gas processing, § 98.232(e)(8) for onshore natural gas transmission compression, and as specified in § 98.232(f)(6) and (8) for underground natural gas storage. [89 FR 42325, May 14, 2024]