Other documents and interviews show that many E.P.A. scientists are alarmed, warning that the drilling waste is a threat to drinking water in Pennsylvania. Their concern is based partly on a 2009 study, never made public, written by an E.P.A. consultant who concluded that some sewage treatment plants were incapable of removing certain drilling waste contaminants and were probably violating the law.

The Times also found never-reported studies by the E.P.A. and a confidential study by the drilling industry that all concluded that radioactivity in drilling waste cannot be fully diluted in rivers and other waterways.

Natural gas drilling in Pennsylvania is heavily dependent on two very problematic practices: the clearing of protected public forest land for profit-making enterprise, and the extreme contamination of ground and surface water through the dangerous, unregulated practice known as hydraulic fracturing (fracking), which dumps hundreds of toxic chemicals into the ground and is alleged to be releasing naturally occuring radioactive isotopes into  the environment. 

Private wellwater is being contaminated, and people living near the drilling fields have shown videos in which they were able to light tap-water on fire, due to the widespread infiltration of natural gas into the water supply. Any organization or individual responsible for the release of toxic chemicals or natural gas into public land or water, or into the wider water supply, must face criminal prosecution for endangering public health and for violating both state and federal environmental safety laws. 

(Source: ProPublica.org)