Reprinted with permission from Environment & Energy Publishing, LLC. Not for republication by Wyoming media.
When U.S. EPA issued a report last month on groundwater contamination in Pavillion, Wyo., many saw it as proof that hydraulic fracturing had contaminated drinking water.
Fracturing contaminated groundwater, EPA said. Not drinking water.
The distinction is important. People in the small central Wyoming town don’t drink from the aquifer, 800 feet down. They drink from water wells, which are generally much shallower.
Finding fracturing chemicals in any groundwater does puncture a big industry talking point — that fracturing has been used safely for 60 years and has never, ever contaminated groundwater. But fracturing done in Pavillion was much closer to the surface — and groundwater — than the mile-deep “fracking” in shale formations like Pennsylvania’s Marcellus.
The groundwater versus drinking water distinction has been lost in the finger-pointing between environmentalists and industry. So have some other key facts. Among them:
- Oil and gas production activities — drilling, not “fracking” — did contaminate wells as shallow as 15 feet with high concentrations of benzene, xylenes and other nasty stuff, according to EPA’s study. But those concentrations still have not been found in drinking water.
- “Material Safety Data Sheets” that the local driller, EnCana Corp., provided were not sufficient to determine what chemicals were in the fracturing fluid used, according to EnCana.
- None of the wells, save two, were sealed with concrete all the way below the drinking water zone. Some of those wells were drilled as recently as 2007.
The report is a draft, and its findings are going to be subjected to peer review. EnCana has disputed most of EPA’s findings and disparaged the agency’s methods. Wyoming’s state oil and gas supervisor, Tom Doll, even suggested that EPA could have contaminated the deep aquifer itself when it drilled deep monitoring wells.
But EPA is standing behind the report. Administrator Lisa Jackson last week sent a letter affirming her support but also explaining some nuances of the study.
EPA’s findings will be tested in the political arena. The House Science Committee is planning a Feb. 1 hearing on the Pavillion report. Republican committee leaders chose a title — “Fractured Science” — that leaves little doubt the report will be attacked.
But if EPA’s findings are accurate, they point to some very basic problems in Pavillion. Oil and gas operators dumped their waste into unlined pits, which was legal at the time. They also did not seal their wells off from drinking water by encasing them in concrete all the way through the drinking water zone, a basic drilling practice laid out in the American Petroleum Institute’s standards.
“At least in retrospect, it appears they didn’t have the wells sealed enough to make sure that fluid couldn’t move up the wellbore,” said Dave Yoxtheimer, a hydrogeologist at Penn State University’s Marcellus Initiative for Outreach and Research.
EnCana spokesman Doug Hock said that the wells in question are located far from drinking water wells and there is no indication they have leaked. He also said, “The contamination associated with these pits is isolated and there is no evidence of impacts to drinking water.”
Material Safety Data Sheets, or MSDS, have been the industry’s preferred method of public disclosure of hydraulic fracturing chemicals. Oil and gas companies have long argued that the sheets amount to full disclosure. Texas’ new public disclosure law requires disclosure only of chemicals from MSDS sheets. But the sheets, which are posted at work sites as instructions for what to do in the event of accidental contact with chemicals, are designed for worker safety rather than long-term water quality monitoring. In this case, an established operator is saying that its own MSDS sheets are not reliable.
As part of the study, EPA got the MSDS from EnCana and compared them to the chemicals it found in the Wind River Aquifer below Pavillion.
“Tert-butyl alcohol, was detected … a known breakdown product of … tert-butyl hydroperoxide (a gel breaker used in hydraulic fracturing),” EPA says on page 35 of its report.
But EnCana says EPA should not use MSDS to link fracturing to contamination in the aquifer.
“Peroxide breaker was never used in the field yet we did record it in the MSDSs because it is possibly used in hydraulic fracturing,” EnCana officials state in written materials prepared for a technical briefing for reporters. “Yet they chose to make that claim despite knowing that peroxide breaker was not used.”
EnCana says EPA never requested more detailed information about what chemicals were used in which specific areas.
“However,” Hock said, “we are planning to provide this information as part of our rebuttal to the draft report.”
EPA concluded that contamination from “constituents associated with hydraulic fracturing” are in the “drinking water aquifer,” around 800 feet down.
But those materials are different than contaminants EPA found in much shallower drinking water wells. And the agency says the contaminants in drinking water are “generally” below health and safety thresholds.
“We have absolutely no indication right now that drinking water is at risk,” Jackson said last year in a televised interview on Pavillion.
Still, after EPA found “petroleum compounds” in 17 of 19 drinking water wells in 2010, the U.S. Agency for Toxic Substances and Disease Registry recommended that some well owners use alternate sources of water for drinking and cooking. The agencies made no conclusion about where those compounds came from.
The EPA report notes that contaminants deeper in the aquifer could flow upward toward drinking water wells. Some stock ponds in the area flow, indicating that water moves up from below. They could also come up through old, forgotten oil and gas wells.
But they haven’t, or at least there is no indication of that in EPA’s study.
To reach most drinking water wells in Pavillion, the contaminants would need to rise upward several hundred feet. But to reach drinking water in shale formations, any contaminants would have to rise upward a mile or more.
In shales like the Marcellus or the Barnett in Texas, gas is trapped in hard rock a mile or so below the surface. Drillers inject millions of gallons of chemical-laced water at extremely high pressure to “fracture” the shale and allow the gas to flow out.
Because it is deeper, it requires more industrial activity at the surface. Drillers use exponentially more water than in the conventional production found in Pavillion, and the water is under exponentially higher pressure.
“I don’t think it’s something that can be extrapolated across formations all over the country,” Penn State’s Yoxtheimer said.
In dismissing the report, industry figures and Wyoming officials have said EPA itself might have contaminated the water in the aquifer when it drilled deep monitoring wells.
But Yoxtheimer said EPA documented a very careful approach to drilling the wells, monitoring everything that went into the wells. He does see a weakness in that the municipal water used to drill the monitoring wells was not tested and suggests its source could be tested, “to fill that gap.”
Some have noted that a portion of EPA’s samples were not tested within the proper time frame. Yoxtheimer said that might invalidate them in a court case, and EPA itself probably would not accept samples that had expired. But he said that given what they were testing for, the time lag probably did not affect the outcome and, if anything, would have shown less contamination because over time such chemicals diminish.
“Technically, the samples weren’t valid,” Yoxtheimer said. “But it probably didn’t affect the quality.”
More troubling to Yoxtheimer is how little data there is overall about fracturing chemicals. EPA said financial constraints prevented drilling more than two deep monitoring wells into the Wind River Aquifer.
“That’s a very limited data set,” he said. “It’s not a data set you can draw large conclusions from.”