State Tightens Air Regs at Gas Facilities

  • A natural gas compressor station in Hickory, PA. Photo: Reid R. Frazier

The Department of Environmental Protection announced it would tighten air regulations at natural gas compressor stations. The new standards will reduce emissions from the most common large engines used at these facilities by 75 to 90 percent, the Department estimates.

DEP will also accept public comment on a “proposed plan approval and operating permit exemption” for emission sources at well sites.

DEP Secretary Mike Krancer hailed the revised standards.

“The steps we are taking now mean far lower emissions at well sites and more efficient compressor stations, resulting in cleaner air as development, production and transmission take place,” Krancer said, in a press release.

The subject of air emissions from the drilling industry has generally taken a backseat to concerns about water quality, though scientists say Marcellus drilling could increase ground level ozone pollution in the coming years.

Clean Air Council’s Jay Duffy said the revisions to the permit, called a General Permit-5 or GP-5, appear to codify widely accepted industry practices, but hasn’t raised the bar on further reducing emissions from compressor stations.

“Yes, it’s an improvement on paper, but the old permit was so out-of-date” that most new equipment already exceeded the old emissions standards, Duffy said.

Kathryn Klaber, CEO of the Marcellus Shale coalition, praised the DEP's new standards in a statement.

"Actual data, from DEP, EIA, EPA and others, continues to further demonstrate the clear air quality benefits associated with natural gas. The revised GP-5 permit aims to reduce emissions by 75 to 90 percent from compressor stations and will further leverage technologies that continue to reduce our industry’s footprint.” 

Compressor stations separate out liquids and other impurities from natural gas extracted at the wellhead, and pressurize the gas to be sent along transmission lines. They are a source of pollution, as well: notably Nitrogen Oxides and Volatile Organic Compounds, which combined, form ground-level ozone in the presence of sunlight. Ozone can lead to respiratory problems, according to the EPA

The revised general permit applies to smaller sources of pollution. Bigger sources are subject to more stringent regulations. Environmental groups have pushed the DEP to “aggregate”, or group together, groups of compressor stations located near one another. This would subject them to stricter regulations. The DEP has resisted aggregating compressor stations located greater than ¼ mile away from one another.

The proposed changes for emissions standards at well sites allows drillers to get an exemption from certain approvals in exchange for controlling emissions and conducting leak detection on the wellhead. The DEP says this is more stringent than currently required by federal air rules.

DEP will accept comments on the proposed changes until March 19.