Encana fights EPA’s water contamination allegations

A drilling rig in Pavillion, Wyo., used to drill a deep water well for testing. (Photo: EPA).

Encana Corp. today ratcheted up its attack on Environmental Protection Agency allegations that the company’s hydraulically fractured natural gas wells are to blame for contaminating groundwater in Wyoming.

The Alberta, Canada-based corporation has already broadly criticized the agency’s findings as flawed, and other industry representatives have joined in too. The American Petroleum Institute questioned the report’s validity, and Wyoming regulators have suggested the EPA’s own water well drilling techniques may be to blame for contaminants that surfaced during testing.

In a conference call with reporters today, Encana’s environmental, health and safety lead for the North Rockies, David Stewart, said the EPA bungled its study of possible contamination in Pavillion, Wyo:

“EPA made critical mistakes . . . at almost every step of the process, from the way it designed the study to the way it drilled and completed its wells, to the way it collected and interpreted its data and (ultimately) its decision to release a preliminary copy of its report without third-party review,” Stewart said.

Stewart said the EPA overlooked the possibility that some of the materials it detected were naturally occurring in the region, where methane is present at very shallow depths and water wells typically extend no lower than 300 feet because of the risk of drilling deeper.

The EPA found natural gas in deep test water wells it drilled in the region. But that gas “was put there by nature, not by Encana,” Stewart said.

The company also disputes EPA’s conclusion that acidity changes and man-made organic compounds the agency detected were linked to hydraulic fracturing. Instead, Encana argues, those materials and changes may have been introduced by the agency itself. Encana fingers the cement EPA used in constructing its monitoring wells as a possible source, especially since samples were drawn when cement may still have been curing.

“The majority of man-made organic compounds detected by the EPA are not used in hydraulic fracturing and were introduced by the EPA in the process of sampling or construction of the deep wells,” Stewart said. “And those that are used were (only detected once)” and haven’t been found again.

The EPA has said it will subject its study to an independent third-party review. The draft report, released earlier this month, represented the first time a federal agency had linked drinking water pollution with the hydraulic fracturing process that is key to extracting natural gas and oil from dense shale rock formations across the U.S. The technique involves pumping mixtures of water, sand and chemicals at high pressures deep underground to break up that rock and unlock the trapped hydrocarbons.

The agency monitored the region from March 2009 through April 2011. After initially discovering methane and dissolved hydrocarbons in some water samples, the EPA broadened its testing of groundwater from wells in the area and installed its own deep monitoring wells.

Ultimately, the agency discovered high concentrations of benzene, diesel range organics and other chemicals in groundwater samples taken from shallow monitoring wells near 33 surface pits used to hold wastewater and drilling material — indicating that they could be a source of contamination.

Other synthetic compounds associated with hydraulic fracturing fluids also were detected in the groundwater. Those included chemicals tied to components of surfactants, foaming agents, fuel additives and other materials often used as part of the fracturing process, including at least one the EPA said “is not expected to occur naturally in ground water.”