WASHINGTON, Jan 11 (Reuters) - The U.S. government is delaying for 8 months a comment period on a report that offered the first evidence in decades that fracking for natural gas contaminates water supplies.
The stall, the third on the 2011 draft report on water in Wyoming, is the latest example of the federal government delaying conclusions on whether hydraulic fracturing, or fracking can lead to pollution in water supplies.
The drilling technique has sparked a revolution in domestic drilling that could one day make the country a net gas exporter.
Environmentalists worry fracking can pollute water and air. Drillers deny that and have said Environmental Protection Agency testing methods may have tainted water samples in Pavillion, Wyoming, the region the EPA examined in the report.
The comment period on the EPA report will now last until September 30 to allow residents, industry and local government more time to have their say and for the agency to include new data, an EPA spokeswoman said on Friday.
The report, released by the EPA in December 2011, said the best explanation for the pollution in Pavillion was that fluids used in hydraulic fracturing, or fracking, migrated up from fracking operations and contaminated an aquifer. The chemicals included benzene, alcohols and glycols, it said.
The EPA conducted the report after local residents complained for years about smells and odd tastes in their drinking water drawn from wells near a natural gas field owned by EnCana Corp of Canada.
Environmentalists have said the report confirms their fears. It is the first time since 1987 the government has given evidence that fracking pollutes water supplies. During fracking, companies force large amounts of water, sand and chemicals deep underground to free gas and oil trapped behind rock.
The hot-button topic made its way to Hollywood in December in the movie "Promised Land", with actors Matt Damon and John Krasinski.
In September, the U.S. Geological Survey released raw data on water quality from a well near Pavillion, but did not provide any analysis on the data, leaving the information open to questions.
The EPA said at the time that the data was "generally consistent" with ground water monitoring data at Pavillion that it had previously released.
Encana, which is providing bottled water to about 20 families in Pavillion, blasted the delay. "It's disappointing, there's no credible reason to delay any further," said Doug Hock, an Encana spokesman. The study is a "waste of time and money," he said, adding his company thinks the USGS data showed the water was not contaminated by fracking.
The EPA said in 2011 Wyoming was much more vulnerable than other areas of the country to water contamination from fracking chemicals because drilling there often takes place much closer to the surface than in other states. Wyoming is one of the country's top state producers of natural gas. Output there has suffered recently due to low prices for the fuel.
In the recent past, the agency also delayed results on a wider study on fracking's effects on national water supplies until 2014, two years after initial targets it had set. (Reporting by Timothy Gardner; editing by Andrew Hay)