The Wyoming Department of Environmental Quality (WDEQ) has released the results of its study into water quality issues in the Pavillion Gas Field Cistern Area east of Pavillion, Wyoming.
This study was carried out from in response to a prior study which took place between 2009 and 2011, where the EPA conducted field investigations in response to complaints of taste and odor issues in well water from Pavilion residents. The report concluded that hydraulic fracturing fluids may have impacted groundwater in the area. Some reviews questioned the major findings in the original report.
Key points are summarized below. Click here for WDEQ’s final report on the investigation.
- Based on the Department’s June and August 2014 sampling of the 13 water supply wells in the area, no organic compounds were identified at concentrations exceeding applicable drinking water standards, other than a pesticide and a phthalate ester. Phthalate is used as a plasticizer in flexible PVC plastics and is a common laboratory contaminant.
- Any inorganic compounds found over applicable drinking water standards were associated with naturally occurring salts, metals and radionuclides. The commission notes that oil and gas drilling mud may have used some of these compounds.
- The study also found it unlikely that fracing had caused any impacts to the water-supply wells, as no evidence was found indicating that fracturing fluids had risen to shallow depths utilized by these wells.
- Gas found in the upper Wind River Formation appears to have originated from upward migration from deeper commercial gas-bearing zones but there is no evidence this has caused water quality issues. Evidence suggests that upward gas seepage was naturally occurring before well development.
- Some gas wells were found to be slowly seeping gas, although the contribution from wells versus natural upward gas migration was undefined and was described as “very difficult to quantify.” Communication between shallow water-bearing zones and intermediate zones was cited as a possible cause of poor water quality, such as higher dissolved solids concentrations, in the shallow zones.
- Taste and odor issues were likely due to bacteria in many of the water-supply wells.
The original study kicked off a controversy around hydraulic fracturing’s effect on groundwater, and in 2013 The Wyoming Oil and Gas Conservation Commission enacted groundwater baseline sampling, analysis and monitoring requirements, which require oil and gas operators to test existing water sources before and after drilling a well.
Landowners must give consent for operators to sample the permitted or adjudicated water sources. These sources include domestic, stock, industrial, irrigation, municipal or other permitted uses of water.
“To date, the State of Wyoming has spent $929,268 for the design, construction and installation of residential cistern systems and a water loading station in the Town of Pavillion. A total of 31 cisterns for 28 landowners have been installed,” a release from the office of Governor Matt Mead said. In 2014, Wyoming committed $400,000 to pay for water delivery to those cisterns.
For those landowners not participating in the cistern program, a bottled water delivery program was available and has been extended through March 31, 2017. The delivery program is provided to 11 homeowners.
