Exxon Mobile Corp., the world’s largest energy company, was charged with illegally dumping more than 50,000 gallons (189,000 liters) of wastewater at a shale-gas drilling site in Pennsylvania.

Exxon unit XTO Energy Inc. discharged the water from waste tanks at the Marquandt well site in Lycoming County in 2010, according to a statement on the website of Pennsylvania’s attorney general. The pollution was found during an unannounced visit by the state’s Department of Environmental Protection.

The inspectors discovered a plug removed from a tank, allowing the wastewater to run onto the ground, polluting a nearby stream. XTO was ordered to remove 3,000 tons of soil to clean up the area. Wastewater discharged from natural-gas wells can contain chlorides, barium, strontium and aluminum, the attorney general’s statement showed.

Full story: ‘Exxon charged with illegally dumping waste water in Pennsylvania’