Q484. Section 98.230(a)(3) states that processing plants "that do not fractionate but have an annual average throughput of 25 MMscf per day or greater" are included in the source category. Is this based on annual average daily flow or max design capacity?

A484. Please note that the 25 MMscf per day threshold in 40 CFR 98.230(a)(3) applies only for Reporting Years (RY) up to and including RY 2024. The 25 MMscf per day threshold is based on annual average daily throughput, which is calculated as the total annual volume of gas received by the plant divided by the number of days of operation during the year. The processing plant throughput must be re-evaluated and compared to the threshold annually.

If your processing operations at a facility as defined in 40 CFR 98.6 do not fractionate, have a throughput of 25 MMscf per day or greater, and meet other criteria specified in 40 CFR 98.230(a)(3) in RY 2024 or any prior reporting year, then you must submit a report for an onshore natural gas processing facility in that reporting year.

If, in any subsequent year up through RY 2024, your annual average daily throughput is less than 25 MMscf per day, you are not required to calculate and report GHG emissions from gas processing in that subsequent year because gas processing would not be an applicable segment. Except as noted below in the discussion of gathering and boosting facilities, you would still be required to report other covered emissions at your facility (e.g., combustion emissions reported under subpart C) in the subsequent year, even if facility-wide emissions are less than 25,000 mt O2e, and you would continue to report until you meet the criteria in 40 CFR 98.2(i) for ceasing to report.  

However, for RY 2016 through RY 2024, you should evaluate whether any operations that do not meet the definition of the onshore natural gas processing industry segment in 40 CFR 98.230(a)(3) are part of a “facility with respect to onshore petroleum and natural gas gathering and boosting” as defined 40 CFR 98.238 and if so, whether emissions from all sources that are part of that “facility with respect to onshore petroleum and natural gas gathering and boosting” exceed the reporting threshold in 40 CFR 98.231(a)(3). If you determine that the processing operations should be reported under the Onshore Petroleum and Natural Gas Gathering and Boosting industry segment, then please note that due to differences in the basin-level definition of a “facility with respect to onshore petroleum and natural gas gathering and boosting” as defined by 40 CFR 98.238 and the contiguous facility definition in 40 CFR 98.6 used for the Onshore Natural Gas Processing segment, reporters that need to change reporting from one segment to the other are encouraged to register these as different facilities within e-GGRT. If you do not already report a gathering and boosting facility in the applicable basin, you are encouraged to register a separate facility (i.e., a separate e-GGRT ID) for the subpart W gathering and boosting facility that covers all gathering and boosting operations in the basin, including processing operations that do not meet the industry segment definition in 40 CFR 98.230(a)(3) if applicable.

Beginning in RY 2025, the 25 MMscf per day throughput threshold is no longer used to define onshore natural gas processing in 40 CFR 98.230(a)(3). If you reported a non-fractionating processing facility with throughput greater than or equal to 25 MMscf per day in RY 2024 that does not meet the definition of onshore natural gas processing in the amended 40 CFR 98.230(a)(3) in RY 2025 (e.g., it was a processing facility solely because it separated CO₂ from natural gas), then as noted above for years prior to RY 2025, you must determine whether the processing operations should be reported under the Onshore Petroleum and Natural Gas Gathering and Boosting industry segment in RY 2025.