A Closer Look: The EPA’s Abandoned Pavillion, WY Investigation

EPA abandons fracking contamination studyIn 2011, the EPA issued a draft water contamination study with a groundbreaking assertion—fracking fluid has contaminated drinking water in Wyoming1.  The study represented the first time that such a claim had been made publicly by the EPA and the first time that such contamination had been scientifically proven.  By all estimates, these findings were about to revolutionize the fracking debate. Two years later, the study has been largely discredited, ignored by the media, and was recently completely abandoned by the EPA.  So what happened?  What’s the story with water contamination in Wyoming?

EPA investigates fracking and water contamination in Wyoming

Over the course of the four year study, a total of 5 test wells were drilled by the EPA after an initial round of testing showed the presence of methane and other hydrocarbons in several municipal and domestic water wells1.  As these substances can sometimes find their way into water wells through natural causes, EPA investigators installed three shallow and two deep monitoring wells to determine if nearby drilling was actually causing the contamination. So what did they find?

In the three shallow test wells drilled near drilling wastewater disposal pits, testing revealed elevated levels of BTEX chemicals, gasoline and diesel range compounds, and other hydrocarbons, indicating that groundwater near these pits was being contaminated by improper disposal of drilling waste products1. But was hydraulic fracturing actually causing pollution of drinking water deep underground?

Analysis of results from the 2 deep monitoring wells was more complex.  Testing of water samples from these wells showed elevated pH levels indicative of drilling activity1.  Chemicals present in drilling and fracking fluids such as potassium, chloride, synthetic organics, BTEX and other oil and gas compounds were also found in samples taken from the two deep test wells1.  This evidence, combined with the fact that logs from nearby oil and gas wells showed casing flaws, led investigators to conclude that hydraulic fracturing in the area had indeed led to deep groundwater pollution in the area1.  A thorough draft of the study was published and awaited peer review.  However, the wait began to extend longer and longer…and eventually the agency announced that the study would not be released for peer review at all3.  So what happened?  Why hold back such an apparently groundbreaking investigation?

Did the EPA frack up?

As it turns out the EPA may have been concerned that their results would not hold up under peer review.  In 2013, following public hearings and analysis by fellow government agencies such as the US Geological Survey, the US Bureau of Land Management, and the State of Wyoming, it became apparent that the EPA themselves had made some of the same drilling mistakes that they were trying to prevent in industry.

For example, according to the Wyoming Department of Environmental Quality (DEQ), the EPA did not case their monitoring wells correctly2.  In a contradiction of their own regulatory requirements, EPA drillers did not line their two deep test wells with stainless steel casing2.  Because the casing was carbon steel rather than stainless steel, it was susceptible to corrosion and thereby to affecting the chemical content of groundwater and fluids in the well.  According to the EPA’s own publication “Handbook of Suggested Practices for the Design and Installation of Ground-Water Monitoring Wells”,

‘the use of carbon steel, low-carbon steel and galvanized steel in monitoring well construction is not considered prudent in most natural geochemical environments…The presence of corrosion products represents a high potential for the alteration of ground-water sample chemical quality.

The surfaces on which corrosion occurs also present potential sites for a variety of chemical reactions and adsorption. These surface interactions can cause significant changes in dissolved metal or organic compounds in ground water samples …’2

EPA drilling mud

Drilling mud and cuttings from an EPA monitoring well.

Furthermore, the EPA failed to clear drilling mud and cuttings from the bottom of their wells, instead leaving debris behind to contaminate water samples with drilling related chemicals2. Consequentially, these combined missteps made it difficult to scientifically prove a link between deep groundwater contamination and fracking.  In mid-2013, under pressure from critics, the EPA abandoned the study altogether, handing it over to the State of Wyoming3. However, not all of the EPA’s findings have been debunked.

Did drilling companies frack up?

While the EPA’s methods in drilling the two deep test wells were indeed flawed, their remaining valid results have all but been forgotten under the cloud of skepticism.  In addition to its deep water testing, the study also found pollution of shallow groundwater with oil and gas compounds near wastewater disposal pits1.

According to all current reports, these results are based on reliable test methods and indicate a need for safer and more effective waste disposal methods by drilling companies. fracking geology diagramFuthermore, both the well casings and local geology made for risky drilling.  As mentioned previously, logs and completion reports for local wells showed sporadic bonding in intervals of casing.  Casings were also extremely shallow, with some extending as little as 110 meters underground—actually shallower than some local domestic wells.

Fracking also occurred at unusually shallow depths. To compound the issue, there is little vertical continuity of a lithographic layer in the Wind River Formation1.  A lithographic layer is a layer of dense shale rock that fluids and gases cannot flow through.  Normally, this layer forms a continuous “cap” over an underground fracking location, preventing contaminants from flowing out and into groundwater.  Because the composition of the Wind River Formation is so laterally variable, there is no such “cap”.

Combined, all these factors make for a high risk situation for water contamination to occur.  However, due to their drilling faux pas, the EPA’s study does not actually constitute proof.


1)       DiGiulio, D., Wilkin, R., Miller, C., & Oberley , G. Environmental Protection Agency, Office of Research and Development. (2012). Investigation of groundwater contamination near pavillion, wyoming draft

2)       Lomax, S. (2013, October 16). Enormous differences between usgs and epa on pavillion. Energy in Depth,

3)       Lustgarten, A. (2013, June 03). Epa abandons fracking study in pavilion, wyoming following similar closed investigations. Huffington Post

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