This page provides an overview of the other emissions from equipment leaks estimated using emission factors source type reporting requirements for Subpart W.
Please see Reporting Form Instructions on downloading the blank reporting form and uploading the completed reporting form.You may also refer to Optional Calculation Spreadsheet Instructions to download the Subpart W calculation spreadsheet.
This page provides an overview of the emissions from equipment leaks estimated using emission factors source type is applicable to following industry segments:
Onshore petroleum and natural gas production [98.230(a)(2)]
Onshore natural gas processing [98.230(a)(3)]
Onshore natural gas transmission compression [98.230(a)(4)]
Underground natural gas storage [98.230(a)(5)]
Liquefied Natural Gas (LNG) storage [98.230(a)(6)]
LNG import and export equipment [98.230(a)(7)]
Natural gas distribution [98.230(a)(8)]
Onshore petroleum and natural gas gathering and boosting [98.230(a)(9)]
Indicate the method used to calculate emissions for this source type via the picklist selection. 
If you have questions about how you should respond to the applicability questions, follow this link for additional help content.
If the facility has the source type, then indicate whether missing data procedures were used.
Reporting Requirements
Table Q.1 Leak Survey Characterization
Facilities that completed a leak survey must report the following data elements:
- Number of complete equipment leak surveys performed during the calendar year (98.236(q)(1)(i))
- For Natural gas distribution facilities conducting multi-year surveys, number of years in the leak survey cycle (98.236(q)(1)(ii))
- Each type of method that was used to conduct leak surveys as described in §98.234(a) (98.236(q)(1)(v))
- Optical gas imaging instrument as specified in §60.18 (98.234(a)(1))
- Method 21 (98.234(a)(2))
- Infrared laser beam illuminated instrument (98.234(a)(3))
- Acoustic leak detection devices (98.234(a)(5))
- Optical gas imaging instrument as specified in §60.5397a (98.234(a)(6))
- Method 21 as specified in §60.5397a (98.234(a)(7))
Table Q.2.i Leak Survey Calculation Method
Facilities that completed a leak survey must report the following data elements, based on the Calculation Method used:
Table Q.2.ii: Emissions Calculated for Component Types Using Default Emissions Factors per Calculation Method 1.
Facilities that use Calculation Method 1 for estimating emissions for equipment leaks found in each equipment leak survey must report the following data elements. Report the count of components surveyed by component type and the emissions from those component types (as calculated by Equation W-30) for your industry segment.
NOTE: Certain component types are only required if they are subject to the well site or compressor station fugitive emissions standards in 40 CFR 60.5397a or if the facility elected to comply with 98.236(q) as indicated in the applicability questions. If no leaks were identified from any components of a component type during the leak survey, enter "0" (zero) in columns G through K for that component type. Required data elements include:
- Component type [98.236(q)(2)(ii)] - this data element is autofilled in the Smart Form
- Emission Factor Used [98.236(q)(2)(iv)]
- Total Number of Components Surveyed by Type [98.236(q)(2)(v)]
- Number of Leaks Identified for the Specified Component Type [98.236(q)(2)(vi)]
- Average Duration of Leaks for the Specified Component Type (hours) [98.236(q)(2)(vii)]
- CO2 Emissions (Surveyed Components Identified as Leaking Only)(mt CO2)[98.236(q)(2)(viii)]
- CH4 Emissions (Surveyed Components Identified as Leaking Only) (mt CH4) [98.236(q)(2)(ix)]
Table Q.2.iii: Emissions Calculated for Component Types Using Direct Measurements per Calculation Method 2.
Facilities that use direct measurements per Calculation Method 2 for equipment leaks found in each equipment leak survey must report the following data elements. Report the count of components surveyed of all component types and the emissions from those component types (as calculated by Equation W-30) for your industry segment.
NOTE: Certain component types are only required if they are subject to the well site or compressor station fugitive emissions standards in 40 CFR 60.5397a or if the facility elected to comply with 98.236(q) as indicated in the applicability questions. If no leaks were identified from any components of a component type during the leak survey, enter "0" (zero) in columns H through K for that component type. Required data elements include:
- Component Type [98.236(q)(2)(ii)] - this data element is autofilled in the Smart Form
- Measurement Method Used [98.236(q)(2)(iv)]
- Total Number of Components Surveyed by Type [98.236(q)(2)(v)]
- Number of Leaks Measured for the Specified Component Type [98.236(q)(2)(vi)]
- Average Duration of Leaks for the Specified Component Type (hours) [98.236(q)(2)(vii)]
- CO2 Emissions (Surveyed Components Identified as Leaking Only) (mt CO2) [98.236(q)(2)(viii)]
- CH4 Emissions (Surveyed Components Identified as Leaking Only) (mt CH4) [98.236(q)(2)(ix)]
Table Q.3 Natural gas distribution facility activity and emissions
Facilities with emission sources listed in 98.232(i)(1) must additionally complete the following data elements. Report the leak survey data from above grade T-D transfer stations and meter/regulator runs for the calendar year and for the current leak survey cycle.
NOTE: If you do not have any metering-regulating stations or transmission-distribution (T-D) transfer stations, enter "0" (zero) into these fields; do not leave the fields blank.
- For leaks surveyed in the calendar year:
- Total number of above grade T-D transfer stations surveyed in the calendar year (98.236(q)(3)(i))
- Number of meter/regulator runs at above grade T-D transfer stations surveyed in the calendar year (98.236(q)(3)(ii))
- Average time meter/regulator runs surveyed in calendar year were operational (98.236(q)(3)(iii))
- For leaks surveyed in the current leak survey cycle:
- Number of above grade T-D transfer stations surveyed in current leak survey cycle (98.236(q)(3)(iv))
- Number of meter/regulator runs at above grade T-D transfer stations surveyed in current leak survey cycle (98.236(q)(3)(v))
- Average time that meter/regulator runs surveyed in the current leak survey cycle were operational (98.236(q)(3)(vi))
- Meter/regulator run CO2 emission factor based on all surveyed T-D transfer stations in current leak cycle, Average of current survey (standard cubic feet per operational hour of all meter/regulator runs) (98.236(q)(3)(vii))
- Meter/regulator run CH4 emission factor based on all surveyed T-D transfer stations in current leak cycle, Average of current survey (standard cubic feet per operational hour of all meter/regulator runs) (98.236(q)(3)(viii))
- Does the facility perform equipment leak surveys across a multiple year leak survey cycle? If 'yes' (98.236(q)(3)(ix)):
- Total number of meter/regulator runs at above grade T-D station facilities (98.236(q)(3)(ix)(A))
- Average estimated time that each meter/regulator run at above grade T-D transfer stations was operational in the calendar year (hours) (98.236(q)(3)(ix)(B))
- Annual CO2 emissions from all above grade T-D transfer stations combined (mt CO2) (98.236(q)(3)(ix)(C))
- Annual CH4 emissions from all above grade T-D transfer stations combined (mt CH4) (98.236(q)(3)(ix)(D))
Table R.1 Equipment leaks calculated using population counts and factors (for Onshore Petroleum and Natural Gas Production and Onshore Petroleum and Natural Gas Gathering and Boosting only)
Facilities that are covered by Onshore petroleum and natural gas production or Onshore petroleum and natural gas gathering and boosting industry segments are required to reporting the following data elements.
NOTE: Do not complete this table for any emission source types/components that are subject to the well site or compressor station fugitive emissions standards in 40 CFR 60.5397a or emission source types/components for which the facility elected to comply with 98.236(q) according to 98.233(q)(1)(iv).
- Geographic Location (according to Table W-1D) [98.236(r)(1)(i)]
- Total number of emission source type, Counte (for gathering pipelines, this value is the number of miles of pipeline per material type) [98.236(r)(1)(ii)]
- Average estimated time that the emission source type was operational in the calendar year, Te (hours) (98.236(r)(1)(iii))
- CO2 emissions (mt CO2) (98.236(r)(1)(iv))
- CH4 emissions (mt CH4) (98.236(r)(1)(v))
Table R.2 Emissions calculated for component types by population count
Facilities that are covered by Underground natural gas storage [98.230(a)(5)], Liquefied Natural Gas (LNG) storage [98.230(a)(6)], LNG import and export equipment [98.230(a)(7)], or Natural gas distribution [98.230(a)(8)] industry segments must complete the following data elements for each component type that uses the population count method for estimating emissions from equipment leaks using Equation W-32A.
NOTE: Do not complete this table for any emission source types/components that are subject to the well site or compressor station fugitive emissions standards in 40 CFR 60.5397a or emission source types/components for which the facility elected to comply with 98.236(q) according to 98.233(q)(1)(iv).The required data elements include:
- Emission Source Type (Eq. W-32A) [98.232] [98.233(r)(1)] - this data element is autofilled in the Smart Form
- Total number of emission source type, Counte [98.236(r)(1)(ii)]
- Average estimated time that the emission source type was operational in the calendar year, Te (hours) [98.236(r)(1)(iii)]
- CO2 Emissions (mt CO2) [98.236(r)(1)(iv)]
- CH4 Emissions (mt CH4) [98.236(r)(1)(v)]
Table R.2 Emissions calculated for component types by population count
Table R.3 Equipment leaks calculated using population counts and factors
Facilities that are covered by the Natural gas distribution [98.230(a)(8)] industry segment are required to report the following data elements, as applicable:
NOTE: If you do not have any above grade transmission-distribution transfer stations or above grade metering-regulating stations that are not T-D stations, enter zero, do not leave blank.
- Number of above grade T-D transfer stations at the facility [98.236(r)(2)(i)]
- Number of above grade metering-regulating stations that are not T-D transfer stations [98.236(r)(2)(ii)]
- Total number of meter/regulator runs at above grade metering-regulating stations that are not above grade T-D transfer stations, CountMR [98.236(r)(2)(iii)]
- Average estimated time that each meter/regulator run at above grade metering-regulating stations that are not above grade T-D transfer stations was operational in the calendar year, Tw,avg (hours) [98.236(r)(2)(iv)]
If your facility has above grade metering-regulating stations that are not above grade T-D transfer stations AND your facility also has above grade T-D transfer stations, you must report the following emissions:
Annual CO2 emissions from above grade metering-regulating stations that are not above grade T-D transfer stations (mt CO2) [98.236(r)(2)(v)(A)]
Annual CH4 emissions from above grade metering-regulating stations that are not above grade T-D transfer stations (mt CH4) [98.236(r)(2)(v)(B)]
Table R.4 Major Equipment Type
Facilities covered by the Onshore petroleum and natural gas production \[98.230(a)(2)\] and Onshore petroleum and natural gas gathering and boosting \[98.230(a)(9)\]
industry segments are required to complete the following data elements.
NOTE: Do not complete this table for any emission source types/components that are subject to the well site or compressor station fugitive emissions standards in 40 CFR 60.5397a or emission source types/components for which the facility elected to comply with 98.236(q) according to 98.233(q)(1)(iv).
- Component count calculation method for all emission source types in Table R.1 other than gathering pipelines (98.236(r)(3)(i))
- Major equipment type (98.236(r)(3)(ii)) - this data element is autofilled in the Smart Form Equipment type present at the facility (98.236(r)(3)(ii)(A))
- Count of major equipment type in Eastern and/or Western US (98.236(r)(3)(ii)(B))
Table R.4 Major Equipment Type (for Onshore Petroleum and Natural Gas Production and Onshore Petroleum and Natural Gas Gathering and Boosting only) 
Table QR.1 Missing Data Table
Facilities that relied on missing data procedures to develop data elements used in calculating emissions from equipment leaks are required to complete the following data elements.
NOTE: Complete only the applicable sections (note that the ID columns are tailored to the different Tables):
- Emission Source Type/ Major Equipment Type
- Service Type
- Component Type
- Geographic Location
- Parameters
- Calculation Method 1 or Calculation Method 2 Used
- Emission Factor or Measurement Method Used
- Measurement Frequency
Number of quarters missing data procedures were used \[98.236(bb)(1)\]
- Total number of hours in the year missing data procedure was used \[98.3(c)(8)\] \[98.236(bb)(2)\]
Procedures used \[98.235(h)\]
Total Emissions
The total emissions roll-up at the top of the sheet reflects the sum of each gas emission reported for the source type. These summations are calculated automatically by the Smart Form and tabulated on the Introduction tab.
