Hydraulic Fracturing Doesn't Contaminate Water Supplies

July 26, 2013

A landmark federal study on hydraulic fracturing, or fracking, shows no evidence that chemicals from the natural gas drilling process moved up to contaminate drinking water aquifers at a western Pennsylvania drilling site. After a year of monitoring, the researchers found that the chemical-laced fluids used to free gas trapped deep below the surface stayed thousands of feet below the shallower areas that supply drinking water, says CBS News.

Although the results are preliminary (the study is still ongoing) they are a boost to a natural gas industry that has fought complaints from environmental groups and property owners who call fracking dangerous.

  • Drilling fluids tagged with unique markers were injected more than 8,000 feet below the surface, but were not detected in a monitoring zone 3,000 feet higher.
  • That means the potentially dangerous substances stayed about a mile away from drinking water supplies.

The boom in gas drilling has led to tens of thousands of new wells being drilled in recent years, many in the Marcellus Shale formation that lies under parts of Pennsylvania, New York, Ohio and West Virginia. That has led to major economic benefits but also fears that the chemicals used in the drilling process could spread to water supplies.

The study, done by the National Energy Technology Laboratory in Pittsburgh, marked the first time that a drilling company let government scientists inject special tracers into the fracking fluid and then continue regular monitoring to see whether it spread toward drinking water sources.

One finding surprised the researchers:

  • Seismic monitoring determined one hydraulic fracture traveled 1,800 feet out from the well bore; most traveled just a few hundred feet.
  • That's significant, because some environmental groups have questioned whether the fractures could go all the way to the surface.
  • The researchers believe that fracture may have hit naturally occurring faults, and that's something both industry and regulators don't want.

Source: "Study Finds Fracking Chemicals Didn't Pollute Water: AP," CBS News, July 19, 2013.

 

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