Fracking found to impact drinking water sources in U.S.

A new study in the United States has found that practices common in hydraulic fracturing, or "fracking," may have widespread impacts on drinking water resources.

The fracking industry, as identified by researchers at Stanford University on the U.S. west coast in a case study of a small Wyoming town, is the only one industry allowed to inject toxic chemicals into underground sources of drinking water.

In a paper published in Environmental Science & Technology, the research paints a picture of unsafe practices including the dumping of drilling and production fluids containing diesel fuel, high chemical concentrations in unlined pits and a lack of adequate cement barriers to protect groundwater.

The well field near Pavillion, of Wyoming, has gone through several corporate hands since the 1960s, but various fracking operators have used acid and hydraulic fracturing treatments at the same depths as water wells in the area.

As part of the so-called frackwater injected into the ground, drilling companies use proprietary blends that can include potentially dangerous chemicals such as benzene and xylene. When the wastewater comes back up after use, it often includes those and a range of potentially dangerous natural chemicals.

In 2008, the residents of Pavillion complained of a foul taste and odor in their drinking water and questioned whether it was related to physical ailments. In 2011, the U.S. Environmental Protection Agency (EPA) issued a preliminary report putting the tiny town with a population of 231 at the center of a growing fracking debate.

The EPA report, which linked shallow fracking to toxic compounds in aquifers, was criticized by the drilling industry as well as state oil and gas regulators. Three years later, having never finalized its findings, EPA turned its investigation over to Wyoming. The state released a series of reports without firm conclusions. In the meantime, the federal Agency for Toxic Substances and Disease Registry has advised area residents to avoid bathing, cooking or drinking with water from their taps.

The Stanford study goes a step beyond the 2011 EPA report to document not only the occurrence of fracking chemicals in underground sources of drinking water but also their impact on that water that is making it unsafe for use.

"Geologic and groundwater conditions at Pavillion are not unique in the Rocky Mountain region," said the study's lead author Dominic DiGiulio, a visiting scholar at Stanford School of Earth, Energy & Environmental Sciences. "This suggests there may be widespread impact to underground sources of drinking water as a result of unconventional oil and gas extraction."

While the study is based on publically available records and documents obtained through the Freedom of Information Act, the Pavillion Field is an area of Wyoming's Wind River Basin pocked by more than 180 oil and gas wells, some of them plugged and abandoned.

"Decades of activities at Pavillion put people at risk. These are not best practices for most drillers," said co-author Rob Jackson, the Michelle and Kevin Douglas Provostial Professor at the School of Earth, Energy & Environmental Sciences.

"This is a wake-up call," said DiGiulio. "It's perfectly legal to inject stimulation fluids into underground drinking water resources. This may be causing widespread impacts on drinking water resources." Endit