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January 04, 2012 Articles

EPA Issues Draft Report on Well Water Contamination in Wyoming

The EPA postulates that the well water contamination might be caused, at least in part, by hydraulic fracturing.

By Robert Carlton and Liz Klingensmith

In 2008, residents of Pavillion, Wyoming, began complaining of objectionable odors and tastes in their well water. In response, the EPA launched an investigation into possible water contamination from gas drilling in the area. The EPA conducted water sampling between March 2009 and April 2011, and released a draft report of its preliminary findings on December 8, 2011. In the draft, the EPA postulates that the well water is contaminated and that such contamination might be caused, at least in part, by hydraulic fracturing—or fracking—activity. While environmentalists have hailed the draft as definitively proving that fracking causes contamination, many in the industry have criticized it as being a premature statement of poor science. The draft is now open for 45-day public comment and 30-day peer-review periods. We review the draft’s contents and then summarizes the energy industry’s response to the draft.

The EPA’s water sampling proceeded in two different parts. First, the EPA sampled shallow well water from the aquifer and collected soil samples in the areas around the pits. The EPA took its shallow samples from wells as shallow as 30 meters below the surface. Next, it tested water from deep wells screened to as deep as nearly 300 meters, focusing on two monitoring wells screened to depths of around 200 to 300 meters. In analyzing the two parts together, the draft finds that the Pavillion aquifer is contaminated and that fracking causes the contamination.

Shallow Findings
In the first part of the investigation, the EPA tested groundwater from existing water wells of varying depths and from shallow monitoring wells that it drilled. In the existing water wells, the EPA detected methane and hydrocarbons. In the shallow monitoring wells near the pits, the EPA detected concentrations of benzene, xylenes, gasoline range organics, diesel range organics, and total purgeable hydrocarbons. The draft theorizes that these tests show that the pits do contaminate the shallow groundwater in the area of investigation. This finding could be significant for the community, as a number of the water wells in the area are shallow. In its early investigations, the EPA also found elevated levels of methane and diesel range organics in deep domestic water wells, prompting it to further investigate the deeper portions of the aquifer.

Deep Findings
To further investigate the findings of methane and diesel range organics in deep domestic water wells, the EPA drilled two deep monitoring wells away from gas production wells, known pit locations, and areas of domestic waste disposal. The EPA drilled one of the deep monitoring wells screened to a depth of 233–239 meters and the other to a depth of 293–299 meters. The draft bifurcates its analysis of the deep findings into an analysis of synthetic compounds and an analysis of methane.

Synthetic Compounds
The EPA found a number of synthetic organic compounds in the deep monitoring well water, including isopropanol, diethylene glycol, triethylene glycol, tert-butyl alcohol, benzene, toluene, ethylbenzene, xylenes (BTEX), trimethylbenzenes, gasoline range organics, and diesel range organics. The EPA found these compounds in concentrations far exceeding levels allowed by the Safe Drinking Water Act. According to the EPA, all of these synthetic organic compounds are either used in hydraulic fracturing or are daughter products of those used in hydraulic fracturing. In pinning the contamination on fracking, the EPA reasons:

  • The contaminants are all found in higher concentrations in the deeper of the two deep monitoring wells, suggesting a deep source of contamination, such as fracking.
  • There is an elevated pH in deep monitoring well water, which could have been caused by the addition of potassium hydroxide, which is used in a crosslinker and in a solvent in gas production.
  • There is elevated potassium and chloride concentrations in the deep monitoring wells as compared to shallow wells. Typically, in the region, chloride concentration decreases with depth, indicating a deep source for the increased concentration. Concentrated potassium and chloride solutions are both used in the fracking process.
  • Certain organic chemicals are more numerous and exhibit higher concentrations in the deeper of the deep monitoring wells. The natural breakdown products of organic contaminants like BTEX and glycols include acetate and benzoic acid. These breakdown products are more enriched in the shallower of the two deep monitoring wells, suggesting that there is a natural upward-lateral migration with a natural degradation and accumulation of daughter products. This upward migration supports the conclusion that the original compounds originated from deep hydraulic fracturing activity and that the daughter products moved up towards the shallow groundwater, which is why they were found in the shallow testing wells. The EPA, however, itself admits that the hydraulic gradients are undefined in the area. Thus, even if the EPA’s assertion that there is an upward migration is correct, it is impossible to know if the groundwater is moving fast enough to support the EPA’s causal theory between fracking and contamination.
  • Well completion drafts and cement bond/variable density logs in the area around the two deep monitoring wells demonstrate examples of sporadic bonding. This bonding takes place outside of production casing that is found directly above intervals of hydraulic fracturing. Inadequate construction of the cement casing around the wells causes the bonds.
  • In the formation, there is little lateral and vertical continuity of hydraulically fractured tight sandstones and no lithologic barrier to stop upward vertical migration of the aqueous constituents of hydraulic fracturing in the event of exclusion from fractures. As a result, there is nothing to stop the vertical migration of the aqueous constituents of hydraulic fracturing in the event of excursion from fractures. This supports the conclusion that contaminants enter the ground at the deep fracking sites and migrate up.

The draft not only draws conclusions based on the presence of synthetic organic compounds in the well water but it also looks to the presence of dissolved methane in well water to support its theory that hydraulic fracturing causes contamination. The tests did not detect methane in shallow well water (less than 50 meters in depth); however, water produced from the deeper wells exhibited near saturated levels of methane. Although some natural gas migration would be expected, the draft notes that natural methane seepage would be expected in levels much lower than those present at Pavillion. The EPA supports its conclusion that fracking causes the increased methane concentrations with the following evidence:

  • Methane concentration in the water wells generally increases the closer the water well is to a producing gas well.
  • The hydrocarbon and isotopic composition of the methane gas found in the water wells is similar to the isotopic composition of the gas produced near Pavillion from fracking.
  • There is inconsistent methane presence around three wells: PGDW30 (a domestic water well), PGDW05 (a domestic water well), and MW01 (one of the deep monitoring wells). During the testing, the highest methane level was detected at the PGDW30 site even though that well is only 80 meters deep. A blowout also occurred during drilling at a depth of only 159 meters adjacent to the PGD05 site. The owner of the PGD05 site also complained of—and the EPA verified—significantly decreased water pumping from the well after hydraulic fracturing began in the area.
  • There are problems with the wells’ cement liners and shallow surface casings. Normally, cement seals off the rock where the drill is welled from the rest of the formation, preventing migration of hydrocarbons or fracking chemicals into the general formation. In many of the wells at Pavillion, however, the cement lining is inadequate. In one gas well, for example, there is no cement liner above a depth of 671 meters even though there are fracking operations nearby above this depth. Additionally, surface casing in the area is generally inadequate. In hydraulically fractured wells, operators normally pour cement casing near the surface of their wells to protect the surface from contamination. In Pavillion, however, this casing often does not extend deeper than the deepest domestic water wells in the area. In fact, in some instances, the surface casing only extends down 110 meters. This combination of problems could allow contaminants to migrate into the un-cemented well and from there migrate to the aquifer.

The Industry’s Response to the Draft
Many in the general public and energy industry, including Encana, are unhappy with the draft’s release. In particular, Encana complains that the EPA should have submitted its findings to be independently peer reviewed before releasing them to the public. Encana also complains that the draft fails to note that numerous other studies in the region have all shown no connection between fracking activity and groundwater contamination. Specifically, Encana and the Wyoming State government conducted seven water quality tests beginning in 2005, which did not find any connection between fracking and poor water quality.

In addition to these general problems, Encana and the energy industry level numerous complaints on the EPA’s scientific findings. They sustain that the contaminants could have had another source. Additionally, they state general problems with the EPA’s testing. Furthermore, they note that the unique geology of the Pavillion area limits the applicability of the results to other parts of the country.

Possible Contamination Sources
One of the draft’s most common criticisms is that it fails to account for the possibility that the chemicals could have had another source. For example, the contaminants could have come from the EPA’s own drilling activity. In its response to the draft, Energy In Depth, an energy industry group, notes that many of the chemicals the EPA found in the deep monitoring wells are commonly used in the drilling of water wells, and thus, there is no way to be sure if those chemicals came from the fracking activity or the EPA’s own drilling. Many also note that the EPA admits that several of the chemicals detected in the monitoring wells, such as certain synthetic organic compounds and petroleum hydrocarbons, are not typically found in drilling additives. This means that those compounds became infused by some other process, which opens up the possibility that all of the contaminants entered the groundwater through another process.

Additionally, many, including Wyoming industry groups, point out that the EPA drilled the deep monitoring wells into gas bearing zones. Thus, it is not surprising that those wells contain gas. Furthermore, Encana notes that only the water from the deep monitoring wells exceeds federal and state drinking water quality standards for constituents related to oil and gas development, whereas the water from the domestic water wells do not. This reinforces that the cause of the EPA’s findings in the deep monitoring wells is that it drilled the wells directly into gas formations or that the chemicals came from the EPA’s own drilling activities. Encana also notes the EPA’s failure to consider other potential sources of contamination, such as septic systems, bacterial activity, and the legacy pits.

Problems with the EPA’s Testing 
Many question the validity of the EPA’s scientific process. For example, the Wyoming governor, among others, has two specific problems with the EPA’s assertion that it found tris (2-butoxyethyl) phosphate in some of the domestic water wells. First, the EPA asserts that it found 2-BE in the domestic well water (which is commonly used in the drilling process) when it actually found tris (2-butoxyethyl) phosphate, which is a common fire retardant used in drinking water wells. Additionally, and perhaps more significantly, two other labs that analyzed the exact same sample reported not being able to detect the compound. Bringing further skepticism to the EPA’s laboratory methodology is the finding of man-made chemicals in the “blank” quality control water samples. According to Encana, the blanks should only contain purified water. Thus, a finding of chemicals in the water “suggest[s] a more likely connection to what it found is due to the problems associated with EPA methodology in the drilling and sampling of these two wells.” Furthermore, many have complained that the EPA did not purge the test wells properly before sampling, the EPA did not mention in its report whether it tested water carried by a truck used in well drilling, and some of the EPA’s samples were improperly delayed, thereby calling its results into question.

Pavillion’s Unique Geology
Additionally, the industry points out that the EPA’s results can be explained by the unique geology of the region and not the fracking process. For example, the region has always been notorious for having poor drinking water. In fact, according to U.S. Geological Survey tests, many of the substances found in the water have been present in Pavillion since monitoring of the water began over 100 years ago, including sulfate, total dissolved solids, potassium, chloride, and high pH levels. Many of these are the same contaminants the EPA found, suggesting that many of the documented issues are preexisting and not related to drilling.

Further calling the EPA’s conclusions into question, its own data shows a decline in potassium in its first deep monitoring well and an increase in the second between October 2010 and November 2011. Scientists point out that this disparity could have only been caused by natural variations in groundwater flow, and thus, the potassium concentration could not have been caused by fracking activity. In fact, Encana maintains that it is the lack of a lithologic barrier or cap rock to stop the upward vertical migration of compounds from the gas formations to the aquifer that has caused the contamination.

Moreover, critics note that even if the EPA is right in some of its Pavillion assertions, its results are unique to Pavillion. First, in Pavillion, fracking takes place both in and just below the aquifer, at depths as shallow as 372 meters. This does not happen in other areas. Typically, fracking does not begin until at least 1,000 meters below the surface. Encana maintains that this unique geologic situation allows the upward migration of deeper natural gas to shallow depths in a completely natural process. Critics also complain that even if the drilling causes contamination, the EPA’s own conclusions show that fracking itself is not the culprit but rather inadequate well construction.

Fracking Future 
Despite the draft’s problems, those opposed to fracking will continue to champion it as definitive proof that more regulation, or perhaps even a total ban on fracking, must be put in place to protect the water table. Conversely, those for the practice will continue to cite the numerous problems with the draft as proof that the Obama EPA is unable to neutrally evaluate the practice. Through uncertainty, one fact remains clear: Fracking will remain a controversial and hotly debated issue.

Keywords: EPA, draft report, contamination, Wyoming, fracking

Robert Carlton and Liz Klingensmith are with Haynes and Boone, LLP, in Houston, Texas.

Copyright © 2012, American Bar Association. All rights reserved. This information or any portion thereof may not be copied or disseminated in any form or by any means or downloaded or stored in an electronic database or retrieval system without the express written consent of the American Bar Association. The views expressed in this article are those of the author(s) and do not necessarily reflect the positions or policies of the American Bar Association, the Section of Litigation, this committee, or the employer(s) of the author(s).