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 Code of Federal Regulations (Last Updated: May 6, 2024)
 Title 40 - Protection of Environment
 Chapter I - Environmental Protection Agency
 SubChapter C - Air Programs
 Part 98 - Mandatory Greenhouse Gas Reporting
 Subpart W - Petroleum and Natural Gas Systems

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

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  • 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
    Valve1 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
    Other2 4.1 2.63
    Leaker Emission Factors - Storage Wellheads, Gas Service
    Valve1 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
    Other2 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]