Encana Oil & Gas (USA), owner of a natural gas field in Pavillion, WY, that the Environmental Protection Agency (EPA) claims is contaminated by chemicals used in production practices (including hydraulic fracturing, or fracking), has called on the agency to suspend the public comment period on a draft report issued in December.

Encana Oil & Gas, a subsidiary of of Encana Corp., “does not believe the data currently available [in the report] establish a connection between hydraulic fracturing and chronic water palatability concerns in Pavillion field. There are serious issues with the EPA’s well construction methods, sampling techniques and data analysis,” wrote John Schopp, vice president for Encana’s northern Rockies’ operations.

Encana asked the EPA to clarify the scope of the comments sought, specifically whether the agency is seeking comments based on the mandate of the EPA Office of Research and Development (ORD), which is focused primarily on quality assurance, science and methodology issues, or on the enforcement/oversight mandate of the agency’s Region VIII Office. The EPA’s Region VIII Office oversees environmental and regulatory issues in Colorado, Montana, North Dakota, South Dakota, Utah and Wyoming.

“There is some question in our mind about this,” said Encana spokesman Doug Hock.

Encana said it has filed a series of Freedom of Information Act [FOIA] requests with the EPA. “What Encana essentially seeks is the same information, and all of it, that the EPA had in hand when it went to prepare the Pavillion Report. Certain of this information is absolutely essential to any meaningful evaluation of the report,” Schopp said.

“Encana has yet to receive any information in response to its FOIA requests and has been told that a complete response will take some time. Given this, and the previously noted issues with the notice, ORD should suspend its request for comment until: 1) the scope of the comments being requests is defined; 2) the proposed charge to the peer review panel is made available to the public; and 3) the EPA provides the public with all of the information that is relevant to a meaningful evaluation of the EPA’s draft report,” the Denver-based producer said. The EPA should then give the public 90 days to comment on the draft report.

Given that the current deadline for public comments is Jan. 27, Encana has called on the EPA to respond quickly to its request.

The draft EPA report, released in early December, found that the groundwater in Pavillion contained chemicals that are normally used in natural gas production practices, such as fracking. Encana said the findings were “conjecture, not factual and only serve to trigger undue alarm,” while Wyoming Gov. Matt Mead classified the draft study as “scientifically questionable,” noting that more testing was needed (see Daily GPI, Dec. 23, 2011; Dec. 9, 2011).

At the request of Pavillion residents in 2008, the EPA began investigating water quality concerns in private drinking water wells. Since then the state of Wyoming, the community of Pavillion and Encana have joined EPA to assess the water quality and identify potential sources of contamination. After meeting with the Wyoming Department of Environmental Quality, EPA began sampling drinking water wells in 2009; a second sampling took place last year (see Daily GPI, Sept. 3, 2010; Aug. 28, 2009).

For the purposes of the test, the EPA constructed two deep monitoring wells to sample water in the aquifer. The draft findings indicated that the groundwater in the aquifer contained compounds likely associated with fracking, the agency said. The EPA also retested private and public drinking water wells in the community and found the samples were consistent with chemicals identified in earlier EPA results released in 2010 and are generally below established health and safety standards.

In addressing the EPA’s discovery of some synthetic chemicals — glycols and alcohols — in the deep monitoring wells, an Encana spokesman said it is just as likely that those chemicals were introduced in the sampling process the EPA used.

Encana said the drilling of gas wells began in the Pavillion area in 1960. Encana acquired the Pavillion asset through a corporate acquisition of Tom Brown Inc. in 2004. From 2004 to 2007 Encana drilled 44 wells. After drilling its last Pavillion well in 2007, Encana said it has not invested in growing production from this mature field where about 125 wells currently produce about 10 MMcf/d. Encana said as far back as the 1880s, the U.S. Geological Survey (USGS) reported about poor water quality in Pavillion. More recent USGS reports dating back to 1959 have documented Pavillion water as unsatisfactory for domestic use due to high concentrations of naturally occurring sulfate, total dissolved solids and pH levels, which commonly exceed state and federal drinking water standards.

Pavillion is a shallow natural gas field, the producer said. Naturally occurring methane exists throughout the subsurface geology, filling channel sands from millions of years ago. This gas is commonly known to have been present in groundwater from domestic wells for decades, dating back to well before any natural gas drilling started, the company said. Pavillion is unusual in that commercial natural gas is present at depths as shallow as 1,100 feet because there is no cap rock forming a barrier between the deeper natural gas and shallow intervals.