Second, state law presumes an energy company is responsible for water contamination within 2,500 feet of an oil or gas well for up to a year after it was drilled – unless the company can prove the water was already bad. Pre-drilling water testing wasn’t universal in the early years of the shale boom, so the industry had no way of defending itself against many contamination claims, said Terry Engelder, a Penn State University geologist and supporter of the shale gas boom. Therefore, drillers might have been held liable for contamination that was already present in the water.
Conversely, drillers were not, at first, required to tell the state about every alleged case of water contamination. Now they are.