The U.S. Environmental Protection Agency (EPA) has abandoned its own report linking groundwater pollution to the controversial gas drilling method known as hydraulic fracturing (or fracking).

EPA officials said they will not finalize a 2011 draft study that found contaminants in the groundwater of Pavillion, Wyoming, were consistent with chemicals used in fracking.

They also said they will not ask outside experts to review the EPA’s research. Instead, the agency will turn the matter over to the state of Wyoming, which intends to work with Encana, the company that conducted the fracking, to resolve the problem. Encana reportedly will pay the state $1.5 million to finish the study.

In 2010, EPA officials informed the residents of Pavillion that testing had revealed the presence of benzene, lead, phthalate, nitrate, 2-butoxyethanol phosphate, petroleum hydrocarbons, methane and high levels of sodium in wells and in groundwater, and they warned locals not to drink tap or well water. They also suggested the use of fans when showering or washing dishes in order to limit the risk of explosion.

Residents of Pavillion were angered by EPA’s decision.

“We went to EPA for help after the state of Wyoming and Encana refused to address the public health impacts of unbridled development in the Pavillion area,” John Fenton, chairman of the group Pavillion Area Concerned Citizens, told the Associated Press. “Now Encana has bought their way back in and is working with the state on a strategy to cover up the mess they've created. Our government's priority is clearly to protect industry rather than Wyoming citizens, our health and our property values.”

The Pavillion drilling is site is surrounded by land occupied by two Native American groups, the Northern Arapaho Tribe and the Eastern Shoshone Tribe. Tribal leaders say they were not consulted, as is legally required, and they claim that the Wyoming Oil and Gas Conservation Commission, which may play a critical role in the new study, is not allowed to make decisions about minerals on tribal land.

-Noel Brinkerhoff, David Wallechinsky

To Learn More:

Some Residents Oppose Wyo.-EPA Frack Study Deal (by Mead Gruver and Ben Neary, Associated Press)

EPA Abandons Study that Linked Fracking, Wyoming Water Pollution (by Ben Geman, The Hill)

Injection Wells: The Poison Beneath Us (by Abrahm Lustgarten, ProPublica)

Pavillion Groundwater Investigation (U.S. Environmental Protection Agency)

Positive University Study on Fracking Was Led by a Gas Company Insider (by Noel Brinkerhoff, AllGov)

Wyoming Town Warned to Use Fans While Showering to Avoid Chemical Explosions (by Noel Brinkerhoff and David Wallechinsky, AllGov)