The U.S. Environmental Protection Agency (EPA) on June 4 released a draft assessment of the potential impacts of hydraulic fracturing on the nation’s water supplies, concluding that there was no evidence of widespread impacts but conceding that data on the subject is limited.
The assessment, conducted at the request of Congress, follows water used for hydraulic fracturing from acquisition, through chemical mixing at the well site, injection of fracking fluids, collection of wastewater (including flowback and produced water), and treatment and disposal.
Hydraulic fracturing—commonly referred to as fracking—of shale gas and oil has led to a resurgence of production in the U.S., reversing decades-old trends toward greater reliance on imports and spawning once-unthinkable debates over exporting U.S. oil and gas. But the process has also been deeply controversial, with environmental groups charging that it is leading to widespread contamination of water resources. In response, Congress asked the EPA to conduct an assessment of existing data and report on the impacts.
Potential Impacts, but Little Evidence
The EPA report, which only reviewed existing data—the agency essentially conducted no original research or fieldwork—concluded that a number of mechanisms existed by which fracking has the potential to impact drinking water resources. These include, the EPA said, “water withdrawals in times of, or in areas with, low water availability; spills of hydraulic fracturing fluids and produced water; fracturing directly into underground drinking water resources; below ground migration of liquids and gases; and inadequate treatment and discharge of wastewater.”
And while the EPA was able to find specific examples of these impacts, including contamination of drinking water wells, “the number of identified cases . . . was small compared to the number of hydraulically fractured wells.”
Industry groups hailed the report as vindication of fracking.
“After more than five years and millions of dollars, the evidence gathered by EPA confirms what the agency has already acknowledged and what the oil and gas industry has known,” said Erik Milito, upstream group director for the American Petroleum Institute. “Hydraulic fracturing has been used safely in over a million wells.”
Marty Durbin, CEO of America’s Natural Gas Alliance, stressed that the industry has been working on reducing the environmental impacts of fracking. “Our industry is committed to continuous improvement, as evidenced by advances in a host of technologies, such as water recycling and use of non-potable water. The natural gas community will continue to work with states to ensure the safe and responsible development of our nation’s abundant and affordable natural gas resource.”
“Continuous safety improvements have been an ongoing part of hydraulic fracturing for 65 years,” Milito added. “That process will continue, with our support, under the oversight of state regulators who are most familiar with their own area’s unique geology, hydrology, and other physical characteristics.”
But environmental groups were equally quick to point out the assessment’s caveats.
Mark Brownstein, vice president, climate and energy program with the Environmental Defense Fund, which has been working with industry groups to study and reduce impacts of natural gas production, was not ready to close the book on the environmental affects of fracking.
“It’s a mistake to think there are no problems just because they don’t turn up in the extremely limited data available,” he said in a blog post on the report. “Indeed, EPA expressly acknowledges in the executive summary that ‘data limitations preclude a determination of the frequency of impacts with any certainty.’”
The EPA in fact noted that the lack of data on actual effects was not necessarily conclusive.
“This finding could reflect a rarity of effects on drinking water resources, but may also be due to other limiting factors,” the report notes. “These factors include: insufficient pre- and post-fracturing data on the quality of drinking water resources; the paucity of long-term systematic studies; the presence of other sources of contamination precluding a definitive link between hydraulic fracturing activities and an impact; and the inaccessibility of some information on hydraulic fracturing activities and potential impacts.”
This suggests the report, which is preliminary, is unlikely to quell the debate over fracking.
“Better and more accessible data on activities surrounding hydraulic fracturing operations is needed,” Brownstein said. “There’s been some progress, and the EPA study is a step in the right direction in terms of better understanding this issue, but by no means are we out of the woods.”
—Thomas W. Overton JD is a POWER associate editor (@thomas_overton, @POWERmagazine).