"The U.S. Environmental Protection Agency is investigating whether specific Marcellus Shale drilling and compressor station operations in Washington County have caused environmental damage that violates federal regulations."

"The federal 'multi-media' investigation of air, water and hazardous materials impacts, which the EPA has not previously acknowledged, began in late September when on-site testing was done and is the initial stage of a possible enforcement action or actions.

'In Washington County, EPA has conducted inspections at active industrial operations including well pads and compressor stations," Terri White, an EPA spokeswoman at the agency's Philadelphia regional office, said in an email response to questions last week."

Don Hopey reports for the Pittsburgh Post-Gazette February 13, 2012. [2]