A report out in the Proceedings of the National Academy of Sciences says chemicals used in fracking have turned up in drinking water in Bradford County, Pennsylvania. There have been all kinds of suspected and hotly debated claims of such contamination. This is one of the very few that have been put out there on the record.

The state regulator concluded that natural gas from the Marcellus Shale contaminated the drinking water. And the company, Chesapeake Energy, settled with three families for $1.6 million dollars.

The authors aren’t totally sure about how the chemicals got into the water. But they say the most likely path is substandard well construction.

The EPA is supposed to release the final draft of its study on fracking and drinking water this spring. The study will incorporate findings from Bradford County, Pennsylvania.