Chief Oil & Gas LLC has paid a $180,000 civil penalty for failing to report a hydraulic oil spill and waste pit liner violations at an idled Marcellus Shale gas well drilling pad in Jefferson Township, Somerset County, a year ago.

A "surprise" state Department of Environmental Protection inspection on June 10, 2010, found evidence that an undetermined amount of hydraulic oil had been discharged onto the ground and a waste pit was close to overflowing, according to Kevin Sunday, a department spokesman. Drilling companies are required to report such spills to the DEP because they are classified as residual waste.

Chief had stopped drilling at the location in March 2010, about two and a half months prior to the DEP inspection. Mr. Sunday said the company was charged with violations of the state Oil and Gas Act, the Clean Streams Law, and the Solid Waste Management Act.

Jefferson Township is five miles west of Somerset, in the headwater drainage of Laurel Hill Creek, a popular trout fishing stream. A majority of the township is in the Forbes State Forest, between Kooser State Park to the south and Laurel Ridge State Park to the north.

Mr. Sunday said he didn't know if any surface water or ground water was affected by the spill. He said the company has successfully remediated the site.