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 Subpart W reporting requirements for the flare stacks source category and emissions from flares.

The flare stack emissions category is applicable to Onshore Petroleum and Natural Gas Production and Onshore Natural Gas Processing segments.

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 facilities and Natural Gas Processing facilities, per §98.232(c)(9) and §98.232(d)(6), respectively
• Source-specific “vented to flare” emissions reporting; as specified in §98.236 for dehydrators, gas well completions and workovers, gas from produced oil sent to atmospheric tanks, transmission tanks, well testing, associated gas venting and flaring, centrifugal compressors, and reciprocating compressors; and
• For Offshore Petroleum and Natural Gas Production facilities, per §98.236(b) emissions from flares are reported separately on the Offshore Emission Source tab.

Because flare stack emission 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)(10):

1. If emissions are reported under a source-specific “vented to flare” reporting category, as listed above, those specific emissions should be reported under that source and not reported under the flare stack emission per §98.233(n) in the facility’s annual GHG reporting.
2. Flare stack emission at Onshore Petroleum and Natural Gas Production facilities and Natural Gas Processing 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).

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

The reporting of flare stack emissions on the Flare Stacks tab in the Subpart W Reporting Form is composed of several elements as follows:

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, the Best Available Monitoring Methods and Missing Data table must be completed.

• For further information, see Best Available Monitoring Methods and Missing Data Reporting.

Reporting Requirements

For each flare, the facility is required to report:

• Unique name or ID number for the flare stack (98.236(c)(12)(x)) - this data element is only required for Onshore Natural Gas Processing facilities
• Does the flare have a continuous flow monitor? (Yes or No) (98.236(c)(12)(i))
• Percent of gas sent to un-lit flare determine by engineering estimate and process knowledge based on best available data and operating records (98.236(c)(12)(iii))
• Does the flare have a continuous gas analyzer? (Yes or No) (98.236(c)(12)(iv))
• Were CEMS used to measure CO₂ emissions for the flare stack? (Yes or No) (98.236(c)(12)(xi))
  • If Yes, the facility must report:
    • If CEMS were used, combusted and uncombusted CO₂ (98.236(c)(12)(iii))
    • Do not report data for the remaining emissions fields
  • If No, the facility must report:
    • Uncombusted CO₂ emissions (98.236(c)(12)(vii))
    • Uncombusted CH₄ emissions (98.236(c)(12)(vi))
    • Combusted CO₂ emissions (98.236(c)(12)(viii))
    • N₂O emissions (98.236(c)(12)(ix))
    • Volume of gas sent to flare (actual cubic feet per year) (98.236(c)(12)(ii))
    • Flare combustion efficiency (decimal value) (98.236(c)(12)(v))
    • Do not report data for "If CEMS were used, combusted and uncombusted CO₂"

Total Emissions

The total emissions roll-up at the top of the sheet reflects the sum of the CO₂ equivalents of each gas emission reported for the source type.  These summations are reflected and aggregated on the Introduction tab.