Hydraulic fracturing to drill for oil and natural gas has not caused widespread harm to drinking water in the United States, the Environmental Protection Agency said Thursday in a report that also warned of potential contamination of water supplies if safeguards are not maintained.
A draft study issued by the agency found specific instances where poorly constructed drilling wells or improper wastewater management affected drinking water, but said the number of cases was small compared to the large number of wells that use hydraulic fracturing, better known as fracking.
The EPA assessment tracked water used throughout the fracking process, from acquiring the water to mixing chemicals at the well site and injecting so-called “fracking fluids” into wells, to collection of wastewater, wastewater treatment and disposal.
“We conclude there are above and below ground mechanisms by which hydraulic fracturing activities have the potential to impact drinking water resources,” the EPA said in the report. But, “we did not find evidence that these mechanisms have led to widespread, systemic impacts on drinking water resources.”
The study was commissioned by Congress and represents the most comprehensive assessment yet of the safety of fracking, a technique that has led to a boom in domestic oil and gas production but also spawned persistent complaints about pollution. Fracking involves the injection of water, sand and chemicals underground to break apart shale rock and free trapped oil or gas.
Thomas Burke, the EPA’s top science adviser, told reporters that given thousands of wells drilled and fracked in the last few years, “the number of documented impacts on groundwater resources is relatively low.”
Still, it’s not accurate to say that there have been no cases of contamination, he said.
“There are instances where the fracking activity itself” led to water pollution, he said.
The report identified several vulnerabilities to drinking water resources, including fracking’s effect on drought-stricken areas; inadequately cased or cemented wells resulting in below-ground migration of gases and liquids; inadequately treated wastewater discharged into drinking water resources; and spills of hydraulic fluids and wastewater.
Industry groups hailed the EPA study as proof that fracking is safe, while environmental groups seized on the report’s identification of cases where fracking-related activities polluted drinking water.
“After more than five years and millions of dollars, the evidence gathered by EPA confirms what the agency has already acknowledged and what the oil and gas industry has known: hydraulic fracturing is being done safely under the strong environmental stewardship of state regulators and industry-best practices,” said Erik Milito, upstream group director of the American Petroleum Institute, the oil industry’s top lobbying group.
But Lauren Pagel, policy director of the environmental group Earthworks, said: “Today EPA confirmed what communities living with fracking have known for years: Fracking pollutes drinking water.”
“Now the Obama administration, Congress and state governments must act on that information to protect our drinking water and stop perpetuating the oil and gas industry’s myth that fracking is safe,” she said.
EPA officials said the report was not intended to prove whether fracking is safe, but instead was aimed at how state regulators, tribes, local communities and industry can best protect drinking water and reduce the risks of fracking. The report has cost $29 million since 2010, the EPA said, with another $4 million expected this year.
The threat of water contamination by fracking and related oil and gas processes has been an ongoing issue in Texas.
The most celebrated case was in Parker County, where resident Steve Lipsky’s video of flaming water sparked an emergency order by the EPA in late 2010. The problem had been blamed on a nearby well drilled by Fort Worth-based Range Resources.
The Railroad Commission investigated and conducted tests of Lipsky’s well and at a 2011 hearing cleared Range, which always steadfastly denied contaminating the groundwater. In 2012, the EPA withdrew its emergency order, although Range agreed to continue testing 20 nearby water wells every three months for a year.
Concerns about water contamination have also been mentioned in cities regulating urban drilling. Fort Worth and other cities do not allow drilling operators to have saltwater injection wells. And during last year’s debate in Denton over the fracking ban, some residents expressed concerns about water contamination.
A study released last year blamed faulty drilling practices — but not hydraulic fracturing itself — as the primary cause of water contamination in the Barnett Shale, a 5,000-square-mile natural gas field that takes in most of North Texas.
In that study, scientists from Duke, Stanford and three other universities studied more than 130 water wells in North Texas and the Marcellus Shale in Pennsylvania. Their findings suggested that methane gas found in water stems from faulty well casings and cement construction designed to protect groundwater during drilling.
On Thursday, Texas Railroad Commission Chairwoman Christi Craddick said the new EPA report confirms what many Texans already knew.
“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,” Craddick said. “There is not one case on the books in Texas where hydraulic fracturing has caused groundwater pollution and it’s my hope the EPA’s finding will contribute to a better public, fact-based understanding of this critical industry technique.”
Texas Sen. John Cornyn said he hoped the EPA study will end “years of demonization from opponents” of fracking, which he said is a “safe and reliable way to take advantage of our vast domestic energy resources.”
Sen. James Inhofe, R-Okla., chairman of the Senate Environment and Public Works Committee, said the report was “the latest in a series of failed attempts” by the Obama administration to link fracking to systemic drinking water contamination.
“The Obama administration is now zero for four,” Inhofe said. “EPA, the U.S. Geological Survey and others have said that hydraulic fracturing is indeed safe.”
But Sen. Edward Markey, D-Mass., said fracking and related activities have the potential to severely impact the nation’s drinking water and endanger public health and the environment.
“While the number of cases [where fracking has contaminated drinking water] may be small, the impacts to public health and safety are large,” Markey said. “EPA must ensure that these activities occur appropriately with robust safeguards to ensure clean and safe drinking water.”
Staff writer Max B. Baker contributed to this report, which includes material from Bloomberg News.