40 C.F.R. § Table W-4A to Subpart W of Part 98

Current through September 30, 2024
Appendix Table W-4A to Subpart W of Part 98 - [Removed effective 1/1/2025] Default Total Hydrocarbon Leaker Emission Factors for Underground Natural Gas Storage

Underground natural gas storageEmission factor
(scf/hour/component)
If you survey using any of the methods in § 98.234(a)(1)
through (6)
If you survey using Method 21 as
specified in
§ 98.234(a)(7)
Leaker Emission Factors-Storage Station, Gas Service
Valve114.849.51
Connector (other)5.593.58
Open-Ended Line17.2711.07
Pressure Relief Valve39.6625.42
Meter and Instrument19.3312.39
Other24.12.63
Leaker Emission Factors-Storage Wellheads, Gas Service
Valve14.53.2
Connector (other than flanges)1.20.7
Flange3.82.0
Open-Ended Line2.51.7
Pressure Relief Valve4.12.5
Other24.12.5

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(f)(6) and (8) .

40 C.F.R. §Table W-4A to Subpart W of Part 98

81 FR 86517, Nov. 30, 2016
81 FR 86517, 1/1/2017; 89 FR 42325, 1/1/2025