DEQ Confirms No Connection Between Oil And Gas And Pavillion Contaminated Water

Dec 24, 2019

Tested well locations around Pavillion
Credit Wyoming Department of Environmental Quality

Wyoming's Department of Environmental Quality's (DEQ) confirmed its 2016 findings that Pavillion, Wyoming's groundwater contamination is not connected to oil and gas activity.

It released a 4,228 page report Monday that dug into questions remaining from the previous version in 2016. The department used improved technology to dive into its past findings and ensure there wasn't some critical compound or bacteria missed.

"That helped in the conclusion of that this was not associated with hydraulic fracturing or other oil and gas activity that exists out there. The bacteria and geochemistry analysis identified the general geochemistry as a source of odor and taste issues that exist out there with a secondary source being sulfate reducing bacteria," said Lily Burkau, groundwater section manager for DEQ's Water Quality Division.

The report explains that gas in the upper Wind River Formation was making its make upward through the porous earth and into groundwater even before gas well development.

DEQ spokesman Keith Guille said that means there are some issues with water wells, but that they're naturally occurring. He also said the investigation is limited without baseline water quality data from before oil and gas development.

Burkau said analysis also uncovered some positive trends with decreasing sulfates, total dissolved solids, and problematic elements that exceeded water quality standards.

The state report is the latest addition to an 11-year-long investigation stemming from decades of water quality concerns in the small central Wyoming town. Analysis into the area's challenges passed from federal hands to state hands after controversial findings from the U.S. Environmental Protection Agency did connect water toxicity to fracking activity.

A model of how upward gas seepage can occur without oil and gas development
Credit Wyoming Department of Environmental Quality

In 2013, the DEQ began sampling 13 water supply wells with funds from Encana Oil and Gas - the operator with development in the area.

In 2014, Wyoming's legislature approved nearly a million dollars to supply 28 area landowners a system to receive clean water. A bottled water delivery program was also established to provide residents in the area with drinking water until March of 2017.

The Wyoming Oil and Gas Conservation Commission is still investigating historic pits operated by oil and gas for uses like production water. That looks into shallower groundwater and soil to see if contamination is there. If there is, the pit would join the DEQ's volunteer remediation program. Four are already under investigation in the area.

The DEQ is also continuing work with the EPA to plug and abandon two monitoring wells.

Have a question about this story? Contact the reporter, Cooper McKim, at cmckim5@uwyo.edu.