Q498. Under subpart W, are we required to calculate potential GHG emissions from compressors at a natural gas processing facility that are only used for refrigeration and use 100% propane?

A498. 98.232 (d) states that “for onshore natural gas processing, report CO2, CH4, and N2O emissions from the following sources”.  For example, if the compressor stream is 100% propane then the emissions will not include CO2, CH4 and N2O emissions and therefore will not have to be reported under subpart W.  However, if the facility exceeds the 25,000 mtCO2e threshold then the owner or operator must report combustion emissions for this compressor under subpart C.