Pennsylvania environmental officials on Tuesday gave permission to an energy company to resume a gas drilling procedure that blasts chemical-laden water into the ground in a village where residents said their well water was polluted four years ago.

The Department of Environmental Protection said Houston-based Cabot Oil & Gas Corp. has met its obligations under a 2010 consent agreement and will be permitted to frack seven previously drilled wells in Dimock Township, a rural area in northeastern Pennsylvania.

Dimock residents have accused Cabot of polluting their water supply with methane gas and toxic chemicals. State regulators had previously blamed faulty wells drilled by Cabot for contaminating the aquifer with explosive levels of methane and had banned the company from drilling and fracking in a 9-square-mile area. Cabot denied it was the source of the pollution but has been working to satisfy regulators that it can operate safely in Dimock.

DEP spokesman Kevin Sunday said in a statement that Cabot needed to demonstrate "that these wells were in full compliance with the law; that their mechanical integrity is sound; and that the wells are not contributing to the previously discovered methane migration."

"Cabot has demonstrated that, and the wells can now be brought into production," the statement said.

Cabot spokesman George Stark said the company is pleased with the decision and intends to "add these wells to the high-producing, clean energy output of Susquehanna County."

The company is already one of the most successful drillers in the Marcellus Shale, a rock formation in Pennsylvania, New York, Ohio and West Virginia that contains the nation's largest reservoir of natural gas. To reach the gas, drillers frack the wells, injecting millions of gallons of water, along with sand and chemicals, to crack open the gas-bearing rock.

The DEP has not cleared Cabot to resume drilling any new wells in the Dimock area but said it may begin producing gas from seven existing wells that were drilled but not yet fracked.

Fracking, formally known as hydraulic fracturing, "was never determined to be a source of contamination, which is why that activity may resume," Scott Perry, the DEP's deputy secretary for oil and gas management, wrote Tuesday in a letter released by the department.

The U.S. Environmental Protection Agency tested wells serving 64 Dimock homes this year and said that contaminants were generally at low levels that did not require additional federal action, a conclusion disputed by some residents who still refuse to use their water wells.

Resident Scott Ely, who lives near one of the Cabot gas wells that is to be fracked, said he worries about the well's integrity and is skeptical that Cabot will safely bring it into production.

"I guess now we're just going to wait to see what comes flying out of our water wells next," said Ely, who asserts his well water is still foul.

Cabot is settling with 32 of 36 Dimock households that sued it in 2009.