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

Link to an amendment published at 89 FR 42325, May 14, 2024.
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 ServiceValve 114.849.51 Connector (other)5.593.58 Open-Ended Line17.2711.07 Pressure Relief Valve39.6625.42 Meter and Instrument19.3312.39 Other 24.12.63 Leaker Emission Factors—Storage Wellheads, Gas ServiceValve 14.53.2 Connector (other than flanges)1.20.7 Flange3.82.0 Open-Ended Line2.51.7 Pressure Relief Valve4.12.5 Other 24.12.5

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).

[81 FR 86517, Nov. 30, 2016]