USGS releases water sample findings from Pavillion

Sept. 27, 2012
The US Geological Survey has released its initial findings after taking samples taken from one of two deep monitoring water well outside Pavillion, Wyo., where some residents complained about drinking water, suggesting natural gas drilling and hydraulic fracturing contaminated certain water wells.

The US Geological Survey has released its initial findings after taking samples taken from one of two deep monitoring water well outside Pavillion, Wyo., where some residents complained about drinking water, suggesting natural gas drilling and hydraulic fracturing contaminated certain water wells.

USGS did not interpret its scientific findings, which were collected as part of a collaboration among the state of Wyoming, USGS, US Environmental Protection Agency, and the Wyoming Tribes. USGS posted two Pavillion documents on its web site. One describes its sampling and analysis plan for the groundwater, and the other provides information from the groundwater-quality samples. EPA constructed the two deep water monitoring wells.

“From a preliminary examination of the[se] data, there appears to be nothing surprising in these results,” Encana Oil & Gas USA spokesman Doug Hock said in an e-mail to OGJ from his Denver office. “More important is the fact that USGS only sampled one of the two monitoring wells. This goes to the heart of concerns raised by state and federal agencies, as well as Encana—EPA’s wells are improperly constructed.”

Hock noted that USGS seems to indicate the agency declined to sample the second monitoring well because the well could not provide a sample that was representative of actual water quality conditions.

Encana Oil & Gas (USA) owns wells in the area and questions the source of some chemicals found in the EPA water well samples (OGJ Online, Jan. 2, 2012).

The Calgary oil company argues contaminants found in Pavillion water wells are naturally occurring, and the two test wells that the EPA drilled in 2010 were improperly constructed.

An EPA draft report from last year identified levels of methane, ethane, diesel compounds, and phenol. Later, EPA retested the water in the Pavillion area.

During March 2009-April 2010, EPA workers collected samples from water wells near Pavillion gas field. In a statement about the draft report, EPA said fracing likely contributed to water well contamination.

In response to the USGS report, Wyoming Gov. Matt Mead said the collaborative effort used to gather these data allowed Wyoming experts to have a say about sampling methodology and testing procedures.

“I feel that the process used to acquire th[ese] data was an improvement on the process used for the draft EPA report last December,” Mead said. “We are now waiting as analysis of th[ese] data is done. It should help inform the peer review process.”

Contact Paula Dittrick at [email protected].