The U.S. Environmental Protection Agency said for the first time it found chemicals used in extracting natural gas through hydraulic fracturing in a drinking-water aquifer in west-central Wyoming.
Samples taken from two deep water-monitoring wells near a gas field in Pavillion, Wyoming, showed synthetic chemicals such as glycols and alcohols “consistent with gas production and hydraulic-fracturing fluids,” the agency said today in an e-mailed statement.
The U.S. gets about one-third of its gas from fracturing, or fracking, in which millions of gallons of chemically treated water and sand are forced underground to break rock and let trapped vapor flow. The findings give ammunition to environmental groups, such as the Natural Resources Defense Council, that have said the drilling risks tainting drinking water and needs stronger regulation.
“This is just evidence of why we need better rules,” Amy Mall, senior policy analyst for the group in Washington, said in an interview. “It’s a game-changer. EPA experts and scientists have recognized that there is real contamination, that there is a real scientific basis for linking it to fracking.”
After complaints from residents of Pavillion, about 230 miles (370 kilometers) northeast of Salt Lake City, the EPA began investigating private drinking-water wells about three years ago. Calgary-based Encana Corp., Canada’s largest natural-gas producer, owns about 150 wells in Pavillion, according to spokesman Doug Hock.
“They’ve used terms like ‘likely,’” Hock said today in an interview. “What they’ve come up with here is a probability. It’s not a definitive conclusion.”
Synthetic chemicals discovered in the aquifer are just as likely “the result of contamination from their own sampling,” he said.
Industry representatives such as Aubrey McClendon, chairman and chief executive officer of Chesapeake Energy Corp., the most active U.S. oil and natural-gas driller among well operators, have said there haven’t been proven cases of fracking fluids contaminating drinking water.
“Try not to be the 51st person to write a story about the alleged contamination of somebody’s water well from fracking,” McClendon said April 8 at the Society of American Business Editors and Writers conference at Southern Methodist University in Dallas. “There have been some issues with drilling wells. They don’t come from fracking.”
In 2010, the U.S. Department of Health and Human Services recommended that Pavillion residents use alternate sources of water for drinking and cooking. While testing detected petroleum hydrocarbons in wells and in groundwater, the agency at the time said it couldn’t pinpoint the source of the contamination.
The EPA dug two deep monitoring wells into the aquifer and found “compounds likely associated with gas-production practices, including hydraulic fracturing,” according to today’s statement. Levels of the chemicals in the deep wells are “well above” acceptable standards under the Safe Drinking Water Act, the agency said.
Fracking chemicals may have entered the aquifer through faulty well construction, gaps in impermeable rock or fractures created during drilling, the EPA said.
“There are various things that can go wrong, but it all points to the fact that we need stronger rules,” Mall said.
Encana has been providing drinking water to about 21 families in Pavillion since August, 2010, Hock said. Some residents were already using outside water sources “because they realize it’s a very poor aquifer,” he said.
Hock said he wasn’t sure if Encana used the synthetic chemicals found in the aquifer when fracking wells in Pavillion.
“I don’t believe that we did,” Hock said. “I don’t know for certain.”
Today’s draft findings are specific to Pavillion, where fracking is occurring “in and below the drinking-water aquifer” and close to water wells, the agency said. The findings will be submitted to an independent scientific review panel.
“Given the area’s complex geology and the proximity of drinking water wells to ground water contamination, EPA is concerned about the movement of contaminants within the aquifer and the safety of drinking-water wells over time,” the agency said.