The Air Permits Division prefers that permit applicants who are calculating fugitive emissions from equipment or lines use the following guidance documents to obtain emission factors.
Oil & Gas Facilities (Including Gas Plants)
Oil and gas facilities should use the guidance document Emission Factors for Oil and Gas Production Operations, API Publication 4615 -- American Petroleum Institute, January 1995. (Factors in this document are based on API data and EPA correlations.)
All Other Facilities