40 CFR Appendix Table W-4A to Subpart W of Part 98 - Default Total Hydrocarbon Leaker Emission Factors for Underground Natural Gas Storage

Table W-4A to Subpart W of Part 98 - Default Total Hydrocarbon Leaker Emission Factors for Underground Natural Gas Storage
Underground natural gas storage 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 - Storage Station, Gas Service
Valve 1 14.84 9.51
Connector (other) 5.59 3.58
Open-Ended Line 17.27 11.07
Pressure Relief Valve 39.66 25.42
Meter and Instrument 19.33 12.39
Other 2 4.1 2.63
Leaker Emission Factors - Storage Wellheads, Gas Service
Valve 1 4.5 3.2
Connector (other than flanges) 1.2 0.7
Flange 3.8 2.0
Open-Ended Line 2.5 1.7
Pressure Relief Valve 4.1 2.5
Other 2 4.1 2.5

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).

[81 FR 86517, Nov. 30, 2016]