Q512. Does Subpart W require reporting of emissions during the salt dome mining process to create an underground natural gas storage facility or does reporting start only when natural gas is introduced for load balancing or storage?

A512. Under 40 CFR 98.230(a)(5) salt dome caverns are part of the underground natural gas storage industry segment when they “store natural gas that has been transferred from its original location.” Emissions reporting is only required  when the storage facility is operational. Greenhouse gas emissions from building of a storage facility are not included in the reporting for subpart W.