Regulations last checked for updates: May 18, 2024

Title 40 - Protection of Environment last revised: May 16, 2024
Appendix - Table W-3A to Subpart W of Part 98—Default Total Hydrocarbon Leaker Emission Factors for Onshore Natural Gas Transmission Compression
Link to an amendment published at 89 FR 42325, May 14, 2024.
Onshore natural gas transmission compression Emission 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—Compressor Components, Gas Service
Valve 114.849.51
Connector5.593.58
Open-Ended Line17.2711.07
Pressure Relief Valve39.6625.42
Meter or Instrument19.3312.39
Other 24.12.63
Leaker Emission Factors—Non-Compressor Components, Gas Service
Valve 16.424.12
Connector5.713.66
Open-Ended Line11.277.22
Pressure Relief Valve2.011.29
Meter or Instrument2.931.88
Other 24.12.63

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(e)(8).

[81 FR 86516, Nov. 30, 2016]
source: 74 FR 56374, Oct. 30, 2009, unless otherwise noted.