Q617. Does EPA offer guidance on estimating a worst case scenario for emissions from transmission storage tanks (i.e., onshore transmission compression and underground storage facilities, beginning in RY 2025) for the purpose of determining applicability?

Q617. Does EPA offer guidance on how to estimate a worst case scenario for GHG emissions from transmission storage tanks (i.e., condensate storage tanks for both onshore natural gas transmission compression facilities and underground natural gas storage facilities, beginning in RY 2025) for the purpose of determining applicability?

A617. The applicability tool does not provide a methodology for estimating the emissions from transmission (condensate) storage tanks because EPA did not have sufficient data to characterize emissions from this source type at the time the applicability tool was developed. Now that emissions have been reported since reporting year 2011, the EPA recommends that a potential reporter check the data for this source type in FLIGHT or Envirofacts for information on the range of typical emissions. Ultimately, it is the facility’s responsibility to consider whether this is a significant source that will affect whether the facility is subject to reporting.