The U.S. Environmental Protection Agency (EPA) has been conducting inspections of natural gas development in Washington County, PA, to make sure it complies with federal environmental laws.

The on-site inspections in late September included well pads and compressor stations at “multiple locations owned by multiple companies,” according to EPA Region III spokeswoman Bonnie Smith.

“While natural gas operators employ various safeguards to minimize the risks inherent to the industry, legitimate concerns have emerged regarding potential environmental impacts,” Smith told NGI’s Shale Daily. Smith declined to comment further about the source or nature of those concerns, but added that, “one should not leap to the conclusion that because we did inspections there will be enforcement.”

The EPA conducts similar “multi-media investigations” across numerous industries to make sure that operations are complying with federal environmental laws for air, water and hazardous materials.

Smith described the multi-media investigations as “a regular part of what EPA does,” pointing to ongoing work in the vinyl chloride sector and among federal facilities. For instance, under a settlement announced in September 2001, Merck & Co. agreed to pay $1.5 million to settle alleged violations after a multi-media investigation of its pharmaceutical manufacturing facilities in Montgomery County, PA, in the Philadelphia area.

The EPA is assessing its findings from Washington County and won’t divulge any information about the operators or facilities involved until that work is complete sometime in the next few months, Bonnie said.

Range Resources Corp. is the most active driller in Washington County, but other operators include EQT Production Co., Chesapeake Appalachia LLC, Atlas Resources LLC and Chevron Appalachia LLC.

The EPA chose Washington County because of the “significant amount of oil and natural gas development occurring there,” Smith said. Although the county lags behind the prolific dry gas counties in the northeastern corner of the state, it is the most active county in liquids-rich southwestern Pennsylvania.

According to data from the Pennsylvania Department of Environmental Protection, from 2009 through January 2012, Washington County had the third most Marcellus wells drilled of any county in Pennsylvania. Bradford led the state with 928, followed by Tioga with 655 and Washington with 458.

The multi-media investigation in Washington is “completely separate” from both the federal study investigating the potential impacts of hydraulic fracturing on drinking water supplies — including a site in Washington County (see Shale Daily, June 24, 2011) — and from the ongoing efforts to gauge whether shale drilling contaminated drinking water supplies in Dimock Township, PA, (see Shale Daily, Jan. 27), Smith said.

“We’ve taken care to make sure that these two activities do not overlap,” she said.