Hydraulic fracturing, the technique that birthed the energy boom, has not had a widespread impact on the quality of the country’s drinking water, according to a landmark study by the U.S. Environmental Protection Agency.

The EPA review of 950-plus papers, reports and information provided by stakeholders found specific instances where fracking affected drinking water resources.

“But they were small compared to the large number of hydraulically fractured wells across the country,” the report says.

The practice has been used in thousands of oil and gas wells. Hundreds of thousands, and even millions, of gallons of water are mixed with sand and chemicals and forced underground at high pressure. The fluid cracks the oil-or-gas bearing rock and lets it flow more freely to the surface.

The assessment, requested by Congress, followed the fracking water cycle: acquiring the water; mixing it with chemicals at the well site; injecting it underground; recovering the produced wastewater; and treating it and disposing of it.

The fracking cycle contains potential vulnerabilities that could affect drinking water, the report says. Those include:

  • Using large volumes of water in areas where the supply is low.
  • Fracking in formations that contain drinking water resources.
  • Poorly cased or cemented wells that result in gas or oil migrating underground to drinking water resources.
  • Inadequately treated wastewater discharged into drinking water resources.
  • Spills of hydraulic fluids and hydraulic fracturing wastewater.

Fracking has been controversial, generating protests, a widely seen documentary, and a number of lawsuits, along with oil and gas. In St. Tammany Parish, protests resulted in a parish-led lawsuit to block a drilling permit.

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