Shale Law in the Spotlight: Pavillion Groundwater Investigation

Wyoming DEQ Concludes That Water Contamination Was Not Caused by Hydraulic Fracturing

Investigations into the contamination of the drinking water supply near Pavillion, Wyoming, commenced nearly a decade ago after some changes were noticed by rural residents in the composition of the water in terms of its color, taste, and smell. Since that time, the causation of this water contamination and its possible connection to hydraulic fracturing specifically, and oil and gas development generally, have been hotly debated. The Pavillion investigation by federal and state authorities has attracted substantial attention because of its focus on the possibility of hydraulic fracturing itself directly leading to the contamination of underground freshwater aquifers. This blog post will review U.S. EPA’s investigative work, together with the work of agencies from the state of Wyoming relating to the Pavillion water well contamination.

The Pavillion investigation site is located within the Wind River Indian Reservation, near the town of Pavillion, in east-central Wyoming. The Wind River Reservation has significant oil and gas resources according to an EIA’s analysis. Between 1884 and the mid-1990s, more than 550 million barrels of crude oil and almost 3 trillion cubic feet of natural gas were produced from reservoirs in the Wind River Basin. The use of hydraulic fracturing started within the Basin in the 1970s.

In 2008, several residents living in Pavillion, Wyoming, complained about adverse changes in drinking water quality resulting in “black, foul-smelling water and health problems ranging from loss of taste and smell and rashes to acute respiratory illness, kidney disease, various cancers and severe neurological problems.” Accordingly, in March 2009, EPA began to test water from 37 private wells and 2 municipal wells in Pavillion, Wyoming, seeking, among other things, traces of volatile organic compounds (VOCs), semi-volatile organic compounds (SVOCs), metals, cyanide, pesticides, and petroleum hydrocarbons that could explain the water contamination. The EPA’s Analytical Results Report, dated August 2009, found VOC contaminants and low-level metal contamination in the water as well as traces of pesticides, iron and sulfate-reducing bacteria, total purgable hydrocarbons and arsenic. The Report stated that the investigation site “may benefit from additional investigation.” In January 2010, EPA released another Results Report analyzing drinking water samples from water and oil and gas wells and found elevated levels of petroleum hydrocarbon compounds and methane in sampled drinking water wells. EPA, however, emphasized that "it [has] not reached any conclusions about how constituents of concern are occurring in domestic wells."

In November 2011, EPA gathered all of the relevant information and data collected through the 2010-2011 sampling into one document. On December 8, 2011, EPA published a draft research report entitled “Investigation of Ground Water Contamination near Pavillion, Wyoming” highlighting the main issues and key findings. Interestingly, Lisa Jackson, then-EPA administrator, had previously made public statements that there had been no cases where hydraulic fracturing itself had contaminated drinking water sources whereas the draft report concluded that “inorganic and organic constituents associated with hydraulic fracturing have contaminated ground water at and below the depth used for domestic water supply” and that “gas production activities have likely enhanced gas migration at and below depths used for domestic water supply and to domestic wells in the area of investigation.”

The draft report was made available for public comment on December 14, 2011, and scientific peer-review on February 8, 2012. The public comment period was supposed to end on January 27, 2012, but in response to calls for further study of the area’s drinking water supply, it was later extended through October 2012.

The release of the draft report drew much criticism from the state of Wyoming and the oil and gas industry, particularly from Encana Oil & Gas Inc. which operated producing gas wells near Pavillion. Shortly after the draft report was released, Encana stated that it “strongly disagree[d]” with EPA’s conclusions condemning them as “irresponsible given the limited number of sampling events on the EPA deep wells and the number of anomalies seen in the data.” Encana added that “given the numerous flaws contained in this report, [it] believes genuine, qualified third-party review is essential.” As for the State of Wyoming, in a letter dated December 20, 2011, Wyoming Governor Matthew H. Mead stated he is “troubled by the EPA’s dismissal of the practical concerns raised by the Wyoming Oil and Gas Conservation Commission (WOGCC), Wyoming Department of Environmental Quality (DEQ) and Encana related to the nature and the protocols employed in conducting the sampling procedures.” Governor Mead then added that “ignoring these concerns while delaying further sampling quality adds to the cloud of the controversy surrounding the underlying work as well as the ultimate report.”

As for the scientific peer-review, EPA issued a statement on March 8, 2012, delaying the peer-review of the draft report “until a report containing the USGS data [was] publicly available.” On September 26, 2012, USGS released two data reports, respectively entitled “Groundwater-Quality and Quality-Control Data for Two Monitoring Wells near Pavillion, Wyoming, April and May 2012” and “Sampling and Analysis Plan for the Characterization of Groundwater Quality in Two Monitoring Wells near Pavillion, Wyoming.” Due to multiple re-sampling actions conducted together with the USGS, the State of Wyoming and the Northern Arapaho and Eastern Shoshone Tribes, EPA, again, extended the public comment period once through January 15, 2013, and another time through September 30, 2013, in order for the public to have sufficient time to review and consider the new collected data. 

On June 20, 2013, the state of Wyoming announced that it would further investigate the groundwater contamination in Pavillion, with the support of EPA.  The state of Wyoming’s investigation would be conducted by the Wyoming Department of Environmental Quality (DEQ) and the Wyoming Oil and Gas Conservation Commission (WOGCC). At that time, EPA stated that “while [it stood] behind its work and data, the agency recognize[d] the State of Wyoming’s commitment for further investigation and efforts to provide clean water and [did] not plan to finalize or seek peer review of its draft Pavillion groundwater released in December, 2011. Nor [did] the agency plan to rely upon the conclusions in the draft report.” EPA provided substantive input to Wyoming’s investigation through research on wellbore integrity and field pits as well as technical comments throughout the years.

In October 2014 and June 2015, after consideration of information compiled by EPA, the WOGCC issued final reports on well integrity and field pits.  Subsequently, on December 18, 2015, the[PR1]  Wyoming DEQ released a draft report entitled “Pavillion Domestic Water Well and Palatability Study” outlining the state of Wyoming’s continued investigation into drinking water quality concerns in the Pavillion area. The public comment period was open until March 18, 2016. On November 10, 2016, the Wyoming DEQ released its final report, entitled Pavilion, Wyoming Area Domestic Water Wells Final Report and Palatability Study and response to comments on the draft report. The Wyoming DEQ contended, amongst other things, that “it is unlikely that hydraulic fracturing fluids have risen to shallower depths intercepted by water-supply wells . . . The likelihood that the hydraulic fracture well stimulation treatments . . . employed in the Pavillion Gas Field have led to fluids interacting with shallow groundwater is negligible.”

With the issuance of this final report by the state of Wyoming, together with EPA’s statement that it would not finalize its draft report, the lengthy investigations into the Pavillion groundwater contamination incident should be concluded. Time will tell whether the matter has been truly resolved. Stay tuned to the Penn State Shale Law blog for any additional developments!

Written by Chloe Marie – Research Fellow