The U.S. Environmental Protection Agency (EPA) has agreed to review standards for measuring volatile organic compounds (VOC) from elevated and enclosed ground flares at natural gas production sites.

EPA earlier this month filed a consent decree in U.S. District Court for the District of Columbia in a case brought by Air Alliance Houston and other environmental groups. They said EPA had failed to review and, if necessary, revise the emissions factor for VOCs every three years, which is required under the Clean Air Act (CAA).

The decree said that by June 5, 2017 EPA will review and either propose revisions to the natural gas VOC emissions factor under CAA or propose a determination that revision is not necessary. Final revisions, or a determination that they are not necessary, are to be issued by Feb. 5, 2018.

There is no admission of negligence on the part of the EPA in the consent decree.

In their complaint, filed Oct. 6, the plaintiffs said EPA guidance documents define emission factors as “‘a tool that is used to estimate air pollutant emissions to the atmosphere.'”

Emission factors are used by industry in reporting air pollution to EPA and state regulators. “EPA and state agencies rely on this data to develop national, regional, state, and local emissions inventories,” plaintiffs said. “These emission inventories are the primary tool that EPA and state agencies use to develop emissions control strategies and make air quality management and permitting decisions.

“EPA published a VOC emission factor for flares at natural gas production facilities in 1985 and continues to maintain this emission factor…The agency has not reviewed or revised this emission factor in accordance with its duty under Section 130 of the Clean Air Act since its original publication.”

Other plaintiffs in the case are Community In-Power and Development Association Inc., Louisiana Bucket Brigade and Texas Environmental Justice Advisory Services. The case is Air Alliance Houston, et al versus Gina McCarthy, administrator U.S. EPA [1:16-cv-01998-RC].