* Shale gas could make U.S. self-sufficient in gas by 2030
* Some in Congress want to give EPA regulatory authority
* Residents say shale gas pollutes water. Drillers deny it
* EPA says it will study environmental, health impacts (Adds EPA statement)
By Ayesha Rascoe
WASHINGTON, Feb 18 (Reuters) - U.S. lawmakers on Thursday announced an investigation of a drilling method that has allowed companies to tap abundant supplies of natural gas in shale beds but has also generated complaints about polluted drinking water.
Some Congress members want to give the Environmental Protection Agency (EPA) authority to regulate hydraulic fracturing technology.
The U.S. House Energy and Commerce Committee said it was investigating the impact of the technology on the environment and public health, and the EPA said it would start working with Congress to study the matter.
“As we use this technology in more parts of the country on a much larger scale, we must ensure that we are not creating new environmental and public health problems,” said committee chairman, Representative Henry Waxman.
“This investigation will help us better understand the potential risks this technology poses to drinking water supplies and the environment, and whether Congress needs to act to minimize those risks,” he said.
Hydraulic fracturing, or “fracking,” injects a mixture of water, sand and chemicals into rock formations at high pressure to force out oil and natural gas. The practice is used to stimulate production in old wells, but is now also used to tap oil and gas trapped in shale beds across North America.
“There are compelling reasons to believe that hydraulic fracturing may impact ground water and surface water quality in ways that threaten human health and the environment, which demands further study,” the EPA said in a statement.
“To address those concerns and strengthen our clean energy future, a budget has been proposed to fund a comprehensive scientific study of hydraulic fracturing and EPA is working with Congress to start that study as soon as possible.”
The committee is seeking information from eight energy companies that use hydraulic fracturing to extract oil and natural gas from unconventional sources, including shale rock.
The lawmakers also asked for information from five smaller fracking companies that make up a growing share of the market: Frac Tech Services, Superior Well Services, Universal Well Services, Sanjel Corporation and Calfrac Well Services.
Fracking is essential to shale gas production, which has sharply boosted U.S. gas output.
The Energy Information Administration estimates this resource could make the United States self-sufficient in natural gas supply by 2030. But environmentalists have warned that fracking, without a national safety standard, endangers human health by contaminating ground water.
Environmental Defense Fund expert Scott Anderson said natural gas was important because it emits less greenhouse gases than coal and oil. But he said extraction technology should not hurt health or the environment.
Residents in gas-drilling areas have complained that their well water was discolored or foul-smelling and that children became sick.
Oil and gas companies say the criticisms are unfounded. They say gas drilling is done thousands of feet below ground, much deeper than most water resources, and note that officials have not linked public health problems to hydraulic fracturing.
Energy In Depth, an interest group backed by independent oil and gas operators, said it welcomed the Congressional probe. Executive Director Lee Fuller touted the industry’s safety practices.
“To the extent the committee’s inquiry into this process helps clear up some of the misconceptions that have come to be associated with it, it’s a study we look forward to contributing to,” Fuller said in a statement. (Additional reporting by Tom Doggett and Timothy Gardner; Editing by David Gregorio and Richard Chang)