This page provides an overview of the reporting requirements for the flare stacks source type 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.

The flare stack emissions source type is applicable to Onshore petroleum and natural gas production (98.236(a)(2)), Onshore natural gas processing (98.236(a)(3)), Onshore natural gas transmission compression (98.236(a)(4)), Underground natural gas storage (98.236(a)(5)), Liquefied Natural Gas storage (98.236(a)(6)), LNG import and export equipment (98.236(a)(7)), and Onshore petroleum and natural gas gathering and boosting (98.236(a)(9)) facilities.

Emissions from flares at subpart W facilities are reportable under one of three authorities within part 98, including:

• Flare stack emissions, as calculated under 98.233(n), are a reportable source for Onshore petroleum and natural gas production (per 98.232(c)(9)) facilities, Onshore natural gas processing facilities (per 98.232(d)(6)), Onshore natural gas transmission compression (per 98.232(e)(6)), Underground natural gas storage (per 98.232(f)(4)), LNG storage (per 98.232(g)(4)), LNG import and export equipment (per 98.232(h)(5)), and Onshore petroleum and natural gas gathering and boosting (per 98.232(j)(7)) facilities.
• Source-specific flared emissions reporting; as specified in 98.236 for dehydrators (98.236(e)), well completions and workovers with hydraulic fracturing (98.236(g)), gas well completions and workovers without hydraulic fracturing (98.236(h)), hydrocarbon liquids sent to atmospheric tanks (98.236(j)), transmission tanks (98.236(k)), well testing (98.236(l)), and associated gas venting and flaring (98.236(m)); and
• For Offshore Petroleum and Natural Gas Production facilities, per 98.232(b), emissions from flares are reported separately on the Offshore Emission Source tab.

Because flare stack emissions at Subpart W facilities are potentially reported in a number of places, the EPA has offered the following simple hierarchy among the reporting categories to ensure that emissions from flares are not double counted per 98.233(n)(9):

1. If emissions are reported under a source-specific flared reporting type, as listed above, those specific emissions should be reported under that source and not reported under the flare stacks emission source per 98.233(n) in the facility’s annual GHG report.
   
   
2.  Flare stack emission at Onshore petroleum and natural gas production, Onshore natural gas processing, Onshore natural gas transmission compression, Underground natural gas storage, LNG storage, LNG import and export equipment, and Onshore petroleum and natural gas gathering and boosting facilities that are not captured under item (1) should be reported under the flare stack emission per 98.233(n). To the extent that monitoring information includes amounts associated with reported emission under (1), those emissions should be deducted from the total emissions reported according to the methods in 98.233(n). If all emissions are deducted, then report 0 for the emissions and report all of the other required data elements. 

Please refer to FAQ 667 for further information on the applicability of combustion emissions at Subpart W facilities.

Indicate if the facility has the source type via the radio buttons.

If the source type is present you must report required elements

If the facility has the source type, then indicate whether missing data procedures were used.

Reporting Requirements

Table N.1  Flare Stacks required data elements include:

For each flare, the facility is required to report:

• Unique name or ID number for the flare stack (98.236(n)(1))
• Were CEMS used to measure CO₂ emissions for the flare stack? (98.236(n)(8) and (12))
  • If Yes, report CO₂ emissions (mt CO₂) (98.236(n)(9))
    • Do not report data for the remaining emissions and activity data fields
  • If No, report:
    • Does the flare have a continuous flow monitor? (98.236(n)(2))
    • Does the flare have a continuous gas analyzer? (98.236(n)(3))
    • Volume of gas sent to flare (standard cubic feet) (98.236(n)(4))
    • Fraction of feed gas sent to un-lit flare (98.236(n)(5))
    • Flare combustion efficiency (decimal value) (98.236(n)(6))
    • Mole fraction of CH₄ in flare feed gas (98.236(n)(7))
    • Mole fraction of CO₂ in flare feed gas (98.236(n)(8))
    • CO₂ emissions (mt CO₂) (98.236(n)(9))
    • CH₄ emissions (mt CH₄) (98.236(n)(10))
    • N₂O emissions (mt N₂O) (98.236(n)(11))

Note that reported CO₂, CH₄, and N₂O emissions should reflect the total emissions after subtracting the amounts reported as flared emissions for other emission source types.

 

Table N.1  Flare Stacks

Enlarge View of Table N.1  Flare Stacks

Enlarge View of Table N.1  Flare Stacks (continued)

Table N.2 Missing data procedures used for Flare Stacks emission calculations is required if your facility relied on missing data procedures to develop data elements used in calculating emissions for flare stacks:

• Unique name or ID number for the flare stack

• Parameters 

• Measurement Frequency

• Number of quarters missing data procedures were used [98.236(bb)(1)] (required only if the measurement frequency was quarterly)

• Total number of hours in the year missing data procedure was used [98.3(c)(8)], [98.236(bb)(2)] (required unless the measurement frequency was quarterly, annually, biannually, or N/A)

• Procedures used for missing data [98.235(h)]

Table N.2 Missing data procedures used for Flare Stacks emission calculations

 

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.