The U.S. EPA agreed to re-evaluate for the first time inmore than 30 years how it assesses certain types of emissions from flaring atnatural gas production sites.
In a consent decree filed Oct. 7, the EPA said it would by mid-2017review the emissions factors it uses for determining volatile organic compound,or VOC, emissions from flares at natural gas production sites. The agency lastset these factors in 1985, according to the Environmental Integrity Project,whose lawsuit brought about the consent decree.
The group expects that the EPA will find that the emissionsfactors are far too low, Sparsh Khandeshi, attorney for the EnvironmentalIntegrity Project, said in an Oct. 7 interview. The EPA's notes on how theemissions factors were originally derived show that the agency assumed levelsof efficiency at the flares that were overly optimistic, Khandeshi said, andwhile the agency has revised these assumptions in other areas, the EPA has notyet applied its better understanding of flaring to VOC emissions at gasproduction sites.
He also questioned whether the EPA's calculations reflectthe appropriate composition of the material being burned at the flares.
Emissions factors have a host of implications. Certainregulations apply to facilities only if they reach particular thresholds ofemissions, so if the emissions factors are low, some facilities may escaperegulation entirely, Khandeshi noted. As the EPA decides what regulations toimpose and how to write them, the total emissions volumes play into whether arule will be cost effective and what technologies might apply, he added.
"Emissions factors are … used in almost every part ofthe Clean Air Act, and … where the technology isn't there to measure it comingout of the flare, it's especially important they get this right,"Khandeshi said, noting that the shale boom makes this a more pressing issue. "Thegrowth in the industry compounds any inaccuracy in the emissions factors."
The Environmental Integrity Project represented Air AllianceHouston, Community In-Power and Development Association, Inc., Louisiana BucketBrigade, and Texas Environmental Justice Advocacy Services in the lawsuit.These groups welcomed the consent decree.
"Members of industry have a saying, 'What gets measuredgets improved.' Only by accurately measuring emissions can we reduce pollutionand protect public health," Adrian Shelley, executive director at AirAlliance Houston, said in a statement.
The American Petroleum Institute said it is reviewing the decree.