A WPX Energy Inc. affiliate has paid a $1.2 million civil penalty to Pennsylvania for a 2012 incident in which it was determined that a leaking impoundment at a well site in Westmoreland County contaminated five private water supplies, the state Department of Environmental Protection (DEP) said Monday.

The fine caps years of investigation into the matter. WPX cooperated with a goal of providing a permanent solution to the water problems. The impoundment, which held treated flowback water, at the Kalp well site in Donegal Township was drained within a week of the leak being discovered.

The fluid seeped into the groundwater at the site and affected the water supplies of families living nearby. Affected households were provided bottled water and treatment systems have been installed. The DEP said it continues to regularly monitor those systems.

While the incident occurred in September 2012, the agency said in 2014 that it determined WPX’s operations had contaminated the water sources. WPX Energy Appalachia paid the penalty to the state’s well plugging fund. DEP said it is based on the impacts to water supplies and the “severity of the leaks.”

The company is also required to remediate the site in accordance with state laws, which includes soil, groundwater and surface water remediation. Today, the company primarily operates in Colorado, Texas, North Dakota and New Mexico. It essentially exited Appalachia in 2014 when it put most of its assets there up for sale.