They're not entirely mixed, because in 2010 there were six or seven studies, and now in 2014 there are something like 132 studies, the overwhelming preponderance of which show negative effects on animal and human health. I would have thought that you should actually exercise the precautionary principle. The precautionary principle says that you can't put the junk in the site unless you, the fracking company, can demonstrate that it's not going to affect the watercourses.
On May 12th, 2015. See this statement in context.