September 30, 2009: Guidance - Calculating VOC Flash Emissions from Crude Oil and Condensate Tanks at Oil and Gas Production Sites

One of the biggest sources of volatile organic compound (VOC) emissions from an oil and gas production site are oil or condensate storage tanks. Flash emissions occur when produced liquid (crude oil or condensate) is exposed to temperature increases or pressure drops during transfer from the production separators or similar sources into atmospheric storage tanks. New information and technology has led to many questions recently as to the various methodologies and their accuracy to estimate flash emissions at oil and gas sites from the oil and condensate tanks.

On December 17, 2008, the Air Permits Division posted a draft Oil and Gas Industry Flash Loss Calculation guidance for comments. Following this guidance, applicants and agency staff can evaluate flash emissions and the methodologies used to estimate these emissions. Please review the final guidance document and the response to comments.