Q494. What is the basis for the 25 MMscfd threshold for gas processing facilities in 98.230(a)(3) and how often must a facility re-evaluate whether it falls below this threshold?

A494. However, please note that if, in year 2, your throughput capacity is less than 25 MMscf per day, you are not required to calculate and report GHG emissions from gas processing in year 2.  You would still be required to report other covered emissions at your facility.  This is because gas processing would not be an applicable segment for year 2.  Nevertheless, your facility would still be required to report in year 2, even if facility-wide emissions are less than 25,000mt CO2e, and would continue to report until you meet the criteria in 98.2(i) for ceasing to report.  The gas processing plant throughput threshold in 98.230(a)(3) is based on annual average throughput.  This throughput is re-evaluated annually.  Once you are subject to the rule (e.g., your facility contains a source category listed in Table A-4), your facility must continue complying with all the requirements of this part, even if the facility does not meet the applicability requirements in a future year (i.e., 25,000 mtCO2e for petroleum and natural gas systems). The definition of the source category for petroleum and natural gas systems, under onshore natural gas processing, refers to a processing facility that does not fractionate and has a throughput of 25MMscf per day or greater.  Because a gas processing facility that is over 25 MMscf per day meets the definition of the source category for subpart W, any facility that becomes subject to the rule in whole or in part because of a natural gas processing facility, would have to continue reporting until it meets the conditions for cessation of reporting in 98.2(i).