The industry maintains that the process is safe, but there have been incidents of drinking water contamination in several states where fracking has been allowed. While the general chemicals used in fracking are known, the industry considers the exact mixes proprietary. There has been talk of divulging the chemicals, but only after drilling is done. PROMISED LAND starring Matt Damon is about fracking's risks. Fracking firms spend millions a year on lobbying for no oversight.