An Encana Corp. official Tuesday delivered a blistering response to the Environmental Protection Agency's (EPA) recent draft report linking water contamination in Pavillion, WY, to chemicals used in hydraulic fracturing (fracking).

The water well testing procedures used by federal officials near Encana's natural gas drilling sites in Pavillion were flawed, which led to results that failed to account for naturally occurring chemicals, said Encana's David Stewart told reporters in a conference call. Stewart runs Encana's environmental, health and safety operations in the Rocky Mountains region and he detailed the company's complaints.

Following two years of water sampling, the EPA claimed in a draft report earlier this month that the groundwater in Pavillion contained chemicals that were normally used in gas production practices, such as fracking (see Shale Daily, Dec. 9). It is the first time a federal agency has linked drinking water pollution with fracking.

Subsidiary Encana Oil & Gas USA Inc., which has developed gas wells in the Pavillion area, objected to the report and said last week many of the EPA's findings were "conjecture, not factual" and "only serve to trigger undue alarm" (see Shale Daily, Dec. 13). Stewart took the criticisms up a notch.

"EPA made critical mistakes at almost every step of the process," he told reporters, "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..." EPA, he said, made the "decision to release a preliminary copy of its report without third-party review."

Federal investigators, Stewart said, overlooked the possibility that some of the materials detected in the area groundwater were naturally occurring. Methane, for instance, often is present at shallow depths, and water wells typically extend no more than 300 feet deep. Natural gas was found in deep test water wells drilled by the EPA but that gas "was put there by nature, not by Encana," said Stewart. EPA's tests also found elevated levels of potassium and chloride, but Stewart countered that high concentrations of the two substances long have been found in the region by the U.S. Geological Survey.

Encana also disputes the acidity changes and man-made organic compounds found in the EPA groundwater tests, which federal regulators claimed could be linked to fracking stimulation practices. Rather, EPA may have introduced those materials when it constructed the monitoring wells since some water samples were taken when cement for the wells was 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," said Stewart. Only one of the EPA's samples found those specific chemicals, he said.

Encana plans to provide more details countering EPA's claims and make additional comments on the EPA draft report during the 45-day comment period, which ends Jan. 27, Stewart said.