The Pennsylvania Department of Environmental Protection (DEP) has determined that WPX Energy Inc.’s Marcellus Shale operations contaminated the water sources of three families living in Westmoreland County, and DEP has issued an order to permanently replace each of their supplies.

A water impoundment that once held treated flowback water is thought to be the cause of contamination, according to an attorney working closely with the families involved. It remains unclear, though, what caused the impoundment to fail.

DEP spokesman John Poister said he couldn’t comment because of pending litigation on the matter, but he issued a statement confirming the contamination and the agency’s order.

“We realize that this is a serious issue for these homeowners,” Poister said in an email. “If WPX fails to comply with this order, it will result in enforcement actions, which could include an immediate permitting freeze until the issue is addressed.”

WPX has drilled one well at the Kalp pad in southwest Pennsylvania’s Donegal Township, located about 50 miles southeast of Pittsburgh in a rural area, and holds two other permits to drill at the location. The well was spud in 2011. Nick Kennedy, an attorney with the Mountain Watershed Association, who has been working with the families, said DEP documents show WPX was cited for the impoundment leak in 2012 after it was discovered.

The families started complaining about fouled water that year, and the issue has been ongoing since then, Kennedy said.

“There is a process regarding orders and appeals, and the company in some cases may elect to appeal a DEP order, which certainly can add time,” Poister said. “In these three cases, there have been a number of complications, and while the company has provided the families with bottled water and other freshwater sources, it’s not a replacement for clean running water in the home.”

WPX has appealed one order to permanently replace drinking water with the state’s Environmental Quality Board. It’s unclear if it will appeal the other two orders, one of which was issued last week.

WPX, which started drilling for natural gas in the state in 2010, holds 500 unconventional permits in Pennsylvania, according to state records, with 131 of those in Westmoreland County. The company produced 88 MMcf/d in the Marcellus last quarter, which is small in comparison to some of its larger assets in the San Juan, Powder River and Piceance basins.

Company spokeswoman Susan Oliver said WPX is cooperating with the DEP investigation and conducting its own water tests, adding that crews were on site to take samples on Thursday. She said WPX will continue to provide fresh water, at its own expense, to all three families involved. Ultimately, she said, the goal is to provide them with “a permanent water solution.”

Kennedy told NGI’s Shale Daily that the Mountain Watershed Association became involved with the families problems after it was notified by a local activism organization. He said he’s been working on the families’ behalf to analyze test results, advise them of their rights and to stay in touch with state regulators.

“What we can say is that it’s required a lot of effort on our part to get clear information from the DEP,” he said. “We haven’t reached out directly to the company. We’ve been dealing primarily with the DEP, and it’s difficult because each family’s situation is a little different in each stage of the regulatory process.”

Kennedy added that WPX still has equipment on site, but he said it hasn’t been actively drilling there since the families began complaining about their water.

“We understand the process can be lengthy as there is litigation and scientific testing involved,” Oliver said. “We know this can be frustrating, but at no time were the families without fresh water once we learned of their situations.”

The DEP confirmed contamination after it conducted tests in June that found elevated levels of chloride, barium and magnesium, among other things, in the water. The company said the impoundment has since been filled and reclaimed.

Oliver said “there is an attorney working with a local activist group that wants to litigate the situation in the media,” referring to Kennedy, but she added that it won’t sway the company’s commitment to a “judicial process and a scientific investigation plan under way.”

Kennedy said he knows that one family has filed a lawsuit against the company seeking damages. Above all, he said, the families want their water sources to be permanently replaced, either with new wells or municipal supplies.