"The EPA has proposed examining every aspect of hydraulic fracturing, from water withdrawals to waste disposal, according to a draft plan the agency released Tuesday. If the study goes forward as planned, it would be the most comprehensive investigation of whether the drilling technique risks polluting drinking water near oil and gas wells across the nation.
The agency wants to look at the potential impacts on drinking water of each stage involved in hydraulic fracturing, where drillers mix water with chemicals and sand and inject the fluid into wells to release oil or natural gas. In addition to examining the actual injection, the study would look at withdrawals, the mixing of the chemicals, and wastewater management and disposal. The agency, under a mandate from Congress, will only look at the impact of these practices on drinking water."