Table W-7 to Subpart W of Part 98—Default Methane Emission Factors for Natural Gas Distribution

Link to an amendment published at 89 FR 42327, May 14, 2024.

Natural gas distribution	Emission factor (scf/hour/ component)	Leaker Emission Factors—Transmission-Distribution Transfer Station 1 Components, Gas Service		Connector	1.69	Block Valve	0.557	Control Valve	9.34	Pressure Relief Valve	0.27	Orifice Meter	0.212	Regulator	0.772	Open-ended Line	26.131	Population Emission Factors—Below Grade Metering-Regulating station 1 Components, Gas Service 2		Below Grade M&R Station, Inlet Pressure >300 psig	1.30	Below Grade M&R Station, Inlet Pressure 100 to 300 psig	0.20	Below Grade M&R Station, Inlet Pressure <100 psig	0.10	Population Emission Factors—Distribution Mains, Gas Service 3		Unprotected Steel	12.58	Protected Steel	0.35	Plastic	1.13	Cast Iron	27.25	Population Emission Factors—Distribution Services, Gas Service 4		Unprotected Steel	0.19	Protected Steel	0.02	Plastic	0.001	Copper	0.03

1 Excluding customer meters.

2 Emission Factor is in units of “scf/hour/station.”

3 Emission Factor is in units of “scf/hour/mile.”

4 Emission Factor is in units of “scf/hour/number of services.”

[76 FR 80594, Dec. 23, 2011]