Contamination and trace elements of compounds used in fracking that were found were traced to reported spills and leaks. Spills and leaks are a concern, but no evidence was found of “subsurface flow” from the shale formation were getting into water sources.

A draft report from the EPA earlier this year backs up the study’s finding. It notes that “there are above and below ground mechanisms by which hydraulic fracturing activities have the potential to impact drinking water resources,” but the researchers “did not find evidence that these mechanisms have led to widespread, systemic impacts on drinking water resources in the United States.”

That is only one study and a draft report, however. Contamination from fracking below the surface, when no malfunctions occur, does not appear to be an issue. More research is needed for that to be definitive.

Previous work from the U.S. Geological Survey has found some evidence of man-made earthquakes connected to fracking. It is not in the process of extraction, but from wastewater storage that causes these earthquakes:

Scientific evidence supporting claims that fracking causes water contamination underground are, so far, weak. Surface contamination can occur, but the even the EPA, in its research, has found that those leaks and spills are rare. Other aspects of fracking offer sturdier footing for fracking worries, but environmentalists who oppose fracking should stay up-to-date on the science if they want to claim their concerns are rooted in reality.

Scientists overwhelmingly vote for the Democratic Party, but that doesn’t make Democratic environmental policy unquestionable.

While fracking can be opposed on other, non-scientific grounds, better information about the scientific and economic impact of the practice will help policymakers , and voters, weigh the tradeoffs for society. Outsized fears and a callous disregard for the environment are both attitudes that should be re-evaluated as knowledge of fracking improves.