Residents of the area around Pavilion, Wyoming have complained about the quality of water from local wells, and some of them believe that hydraulic fracturing or other oil and gas activity may be to blame.  Late last week, the EPA released its draft report regarding its investigation of alleged ground water contamination near Pavillion, but the significance of the EPA's test results are disputed.  In a press release, the EPA stated: "EPA constructed two deep monitoring wells to sample water in the aquifer.  The draft report indicates that ground water in the aquifer contains compounds likely associated with gas production practice, including hydraulic fracturing."

The operator of the natural gas wells that the EPA believes caused the problem is Encana.  Encana issued a statement which noted that the EPA has tested water from monitoring wells that the EPA itself drilled just for the purpose of testing, and also water from domestic wells that local residents actually use to obtain water.  As for the monitoring wells, Encana stated that the EPA "drilled two deep monitoring wells into a natural gas reservoir," and it is "entirely expected" to find "components of natural gas" in such a reservoir.  Encana stated that the EPA's testing of domestic water wells "found no indication of impacts from oil and gas activity."  In addition, Encana stated:

The Pavillion area natural groundwater has a long history of poor quality.  Recent drinking water sample results are consistent with studies published by the U.S. Geological Survey and others over the past 50 years, prior to natural gas development in the area.

The Petroleum Association of Wyoming issued a statement that called the EPA's draft report "reckless" and "irresponsible."  The Association stated: "After several rounds of testing of private water wells, only one organic compound was found to exceed State or Federal Drinking Water standards.  This compound is an additive in plastics and one of the most commonly detected organic compounds in water." 

The EPA's report states that "[a]lternative explanations were carefully considered," but that the Agency believes oil and gas activity is the likely cause of the contamination the Agency claims to have found. 

Aside from the challenges that have been asserted to the EPA's conclusions, the Pavillion findings might have limited relevance to most circumstances in which companies perform hydraulic fracturing.  The EPA's own press release stated that the Agency's "draft findings are specific to Pavillion, where the fracturing is taking place in and below the drinking water aquifer and in close proximity to drinking water wells — production conditions different from those in many other areas of the country."  Indeed, in most shale plays, the formation being fractured is  more than a mile below drinking water aquifers, and often is separated by layers of impermeable rock.