The Environmental Protection Agency released the draft of a long-awaited study on the potential impacts of hydraulic fracturing — fracking — for oil and natural gas on drinking water, and individuals on both sides of the debate have misrepresented the study’s findings:

A Republican senator said the report “confirms” that fracking is “safe.” In fact, the EPA reported specific cases of water contamination, and an EPA official said the report makes no determination of safety.

An environmental group said the EPA “found impacts” on drinking water but “cannot be sure how widespread those impacts are.” In fact, the EPA said it found no evidence of “widespread, systemic impacts on drinking water,” and that the number of instances of contamination has been small compared with the number of wells.

Fracking involves the injection of water, sand and chemicals into rock formations deep underground. This allows oil or natural gas to seep out, and back up through a well in order to be collected. Sen. James Inhofe, a Republican from Oklahoma and chairman of the Committee on Environment and Public Works whose claims on fracking we have covered before, said in a press release that the study confirmed that fracking is safe:

Inhofe, June 4: EPA’s report on hydraulic fracturing confirms what we have known for over 60 years when the process began in Duncan, Oklahoma — hydraulic fracturing is safe.

The study did not conclude as such, and in fact reported specific cases of water contamination.

Meanwhile, the very same study produced an opposite reaction from opponents of fracking. Here is how Amy Mall, a senior policy analyst with the environmental nonprofit Natural Resources Defense Council, described the results:

Mall, June 4: This draft study provides solid scientific analysis that fracking has contaminated drinking water around the country. … But despite the holes [in the study], it is clear EPA has found impacts — they just cannot be sure how widespread those impacts are.

In fact, the EPA noted that the number of cases of contamination was small compared with the number of wells.

Both of these reactions, and others like them on both sides, portray the finding as a definitive victory for one of two sides — either that fracking does or does not harm drinking water supplies. The reality of the situation is more nuanced: The EPA did find that there have been instances where fracking and related activities contaminated water, but it also found that these problems were relatively rare, and not “widespread” or “systemic.”

Here is an extended passage from the EPA report’s executive summary:

EPA, June 4: From our assessment, we conclude there are above and below ground mechanisms by which hydraulic fracturing activities have the potential to impact drinking water resources. These mechanisms include 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. We did not find evidence that these mechanisms have led to widespread, systemic impacts on drinking water resources in the United States. Of the potential mechanisms identified in this report, we found specific instances where one or more mechanisms led to impacts on drinking water resources, including contamination of drinking water wells. The number of identified cases, however, was small compared to the number of hydraulically fractured wells.

Clearly, Inhofe is incorrect that the EPA found fracking to be “safe,” as there have been “specific instances” of contamination. In fact, Tom Burke, the EPA’s deputy assistant administrator in the office of research and development, told reporters in a press call that “[i]t’s not a question of safe or unsafe.” Rather it is a way to address “vulnerabilities” and reduce the risk of harm to water supplies.

The EPA’s study describes several of the “instances” of contamination. For example, the cement placement in a natural gas well in Colorado was “inadequate,” allowing methane and benzene to escape the well and infiltrate drinking water resources. The study also documented 151 spills of fracking chemicals on the surface, though it remains unclear if these will affect groundwater in most cases.

The NRDC is also incorrect to say that we lack information on “how widespread” the impacts are — the EPA specifically notes the number of cases is small in comparison with the number of wells. The study also did note that the small number of cases “could reflect a rarity of effects” on drinking water, or it could be an underestimate of those effects due to factors including a lack of baseline data on water quality.

Fracking and water contamination is a contentious issue, and both sides of the debate are spinning a nuanced finding to reflect their positions.

Update, June 18: Two sentences in this piece have been updated to reflect that the EPA studied fracking for both oil and natural gas, not just natural gas.

Disclosure: The author of this post has previously written for and provided Web production services for OnEarth, a publication of the Natural Resources Defense Council, on a freelance basis.

Editor’s Note: SciCheck is made possible by a grant from the Stanton Foundation.

– Dave Levitan