The U.S. Environmental Protection Agency says it has found no evidence that hydraulic fracturing has “led to widespread, systemic impacts” on the nation’s drinking water supplies, though the practice has harmed water in some cases.
That’s according to the draft released Thursday of a much-anticipated report on the revolutionary but politically divisive method of bolstering oil and gas production by blasting apart underground rock with a high-pressure mixture of water, sand and chemicals.
“We conclude there are above and below ground mechanisms by which hydraulic fracturing activities have the potential to impact drinking water resources,” the report’s executive summary states. “We did not find evidence that these mechanisms have led to widespread, systemic impacts on drinking water resources in the United States.”
A Texas regulator and industry representatives touted the conclusion as they seek to quell public concerns that the practice – widely known as fracking – poses danger to drinking water.
“Texans have known for sixty-plus years that hydraulic fracturing, when well-regulated, is not only safe but critical to unleashing America’s true oil and gas production potential,” Christi Craddick, chairwoman of the Texas Railroad Commission, said in a statement. “It’s my hope the EPA’s findings will contribute to a better public, fact-based understanding of this critical industry technique."
Katie Brown, a spokeswoman for Energy In-Depth, wrote for the industry group’s blog that "it couldn’t be clearer that shale development is occurring in conjunction with environmental protection."
Still, the 998-page analysis gave environmentalists and other critics of the practice some ammunition.
“The EPA's water quality study confirms what millions of Americans already know — that dirty oil and gas fracking contaminates drinking water,” said Michael Brune, executive director of the Sierra Club. “Unfortunately, the EPA chose to leave many critical questions unanswered.”
The study, which the agency called the "most complete compilation of scientific data to date," focused on five issues related to drinking water: withdrawals of millions of gallons of water needed to frack each well; the mixing of chemicals into fracking fluid; the high-pressured injections of that fluid; tainted water that flows back to the surface; and wastewater treatment and disposal.
“We found specific instances where one or more mechanisms led to impacts on drinking water resources, including contamination of drinking water wells,” the findings said. “The number of identified cases, however, was small compared to the number of hydraulically fractured wells.”
The agency said its findings could either show that fracking presents a relatively small risk to U.S. water supplies, or that there is not enough data to find otherwise.
The study did not examine effects on air quality, or public health at large.
Companies drilled and fractured as many as 30,000 oil and gas wells in the U.S. from 2011 throughout 2014, the agency estimated, while many older wells were also fracked. Texas was home to nearly half the wells fracked since 1990, with Colorado a distant second, followed by Pennsylvania and North Dakota.
Among the study’s other findings:
- Fracking typically uses less than 1 percent of total water use across the country, but the percentage is often far higher in heavily drilled areas. In 2011 and 2012, fracking guzzled at least 10 percent of water used in 6.5 percent of counties where operators disclosed information on the national website FracFocus.org. In 1 percent of those counties, fracking accounted for at least half of all water use.
- Heavily fracked South and West Texas face particular risks from water withdrawals for fracking because of a combination of drought and dwindling groundwater supplies.
- The agency tracked 151 spills of fracking fluid or chemical spills at well sites in 11 states between January 2006 and April 2012, with volumes per spill ranging from five gallons to more than 19,000 gallons. “These cases were likely a subset of all fracturing fluid and chemical spills during the study’s time period,” the report said.
- The agency identified 134 chemicals in fracking fluid that flows back to the surface. It could only trace the properties of 86 of those chemicals.
The agency will finalize the study after its Scientific Advisory Board reviews and comments on it.
Disclosure: The Sierra Club was a corporate sponsor of The Texas Tribune in 2011. A complete list of Tribune donors and sponsors can be viewed here.