A study conducted by Penn State University researchers incorrectly said seven wells had been contaminated by hydraulic fracking in Pennsylvania, when in fact just one showed a heightened level of bromides, The Associated Press reports.

Bryan Swistock, one of the researchers, told the AP in an email that a Center for Rural Pennsylvania policy requires reports to be passed through the General Assembly before being published. That was the reason their study was not subjected to independent scientific peer review.

Just one well displayed greater levels of the “salty mineral compounds that can combine with other elements to cause health problems,” according to the news outlet. The misrepresentation was due to an error in results from an independent water-testing lab.

A spokesman from gas industry representative the Marcellus Shale Coalition, Patrick Creighton, noted in an interview with the source that almost 20 percent of wells tested before fracking in Pennsylvania got underway. On top of that, approximately 40 percent of the wells, also “failed at least one water quality standard” before drilling began, the sources quotes Creighton as saying.

Writing for the New Yorker, Elizabeth Kolbert points out that virtually any kind of energy extraction creates some risks: mining for coal, for instance, generates nearly double the amount of greenhouse gases as natural gas creates.

“In the end, the best case to be made for fracking is that much of what is already being done is probably even worse,” Kolbert concludes.