The Gas Processors Association (GPA) filed comments with the U.S. Environmental Protection Agency (EPA) to recommend the EPA withdraw its proposed changes to section 13.5 of AP-42, Compilation of Air Pollutant Emission Factors. The EPA proposed a substantial increase in the emission factor for NOX emitted from industrial flares. GPA member companies own facilities using the AP-42 emission factors, and the proposed changes would increase the regulatory burdens on those companies.

The GPA expressed concern with the sample size used to develop the new emission factors, which was based on only five new data points, with one value from a facility “orders of magnitude higher than the average of the other four.”

GPA comments said that emission factors apply to different facility types within oil and gas operations, as well as other industry sectors, but EPA has based its proposed factors on flare data from one type of flare, from only one type of facility—petroleum refineries—plus a test facility.

“Refineries are large sources of air emissions and typically fall into major source categories. The majority of midstream facilities with flares are minor sources and use flares as control devices and stay below major source thresholds,” said GPA President and CEO Mark Sutton. “Increasing the NOX emission factor by a factor of 42 as proposed could result in hundreds of midstream facilities becoming inappropriately categorized as major sources. The increase in permit applications alone could result in a significant regulatory burden on both the regulatory authorities and the regulated community.”

The GPA recommended that all proposed changes to AP-42 Section 13.5 be withdrawn. The GPA suggested that new industrial flare emission factors be determined by using data from multiple industry segments. In addition, GPA asked the agency to consider determining separate factors for different flare types, feed composition and industrial applications before making any changes to the emission factors.