Fracking Made Pennsylvania Water Foam

White foam found in some northeastern Pennsylvania water wells from 2010 to 2012 was likely a byproduct of nearby fracking, according to a new study published by the Proceedings of the National Academy of Sciences journal. Scientists identified a variety of organic compounds present in the water at low levels, and found that they were the same or similar to compounds used in hyrdraulic fracturing. (None of the compounds, other than natural gas, were found to be at unsafe levels.) An inability to get samples directly from the fracking site—because the industry has refused to disclose the chemical mixes they use—has made the cause of the foaming impossible to prove conclusively, but scientists say a variety of factors make fracking “the most probable source.”