The Environmental Protection Agency (EPA) has sent letters to nine major national and regional hydraulic fracturing (hydrofracing) service providers to assess the impact of the natural gas production practice on drinking water quality and public health.

"I am requesting your cooperation in a scientific study the Environmental Protection Agency is conducting to gather information about the hydraulic fracturing process...In numerous U.S. communities where fracturing is under way, citizens are voicing serious concerns," EPA Administrator Lisa Jackson said in letter to the nine companies.

The companies are BJ Services, Complete Production Services, Halliburton, Key Energy Services, Patterson-UTI, PRC Inc., Schlumberger, Superior Well Services and Weatherford.

Jackson said EPA was seeking information on several topics, including chemical composition of fluids used in hydrofracing, the impacts of the chemical fluids on human health and the environment, standard operating procedures at hydrofracing sites, and the sites where hydrofracing has been conducted.

The letters are part of the study, which the EPA began in March, of the potential risks associated with hydrofracing -- a technique used to stimulate production of natural gas from wells drilling in gas shales (see Daily GPI, March 19). The study was authorized by Congress.

While "natural gas is an important part of our nation's energy future...EPA will do everything in its power, as it is obligated to do, to protect the health of the American people and will respond to demonstrated threats while the study is under way," she said.

Producers say they are confident that the study -- if conducted objectively -- will show hydrofracing to be safe. Hydrofracing is a process in which fluids are injected at high pressure into underground rock formations to fracture the rock and increase the flow of fossil fuels.

This will be the EPA's second study of the hydrofracing process. A 2004 study found that hydrofracing was not a threat to the environment or public health, according to producers. However, hydrofracing opponents claimed that the study was biased.

The initial results of the ongoing EPA study are expected to be released in late 2012, according to the agency. The EPA also said it will ask industry to provide additional information later regarding fluid disposal practices and geological features that will help it carry out the study.

The EPA has asked the nine companies to provide the information on a voluntary basis within 30 days, and to contact the agency within seven days on whether they will be able to provide all of the information sought. The agency noted that the information being sought already has been provided separately to Congress.

The "EPA expects the companies to cooperate with these voluntary requests. If not, EPA is prepared to use its authorities to require the information needed to carry out its study," Jackson said.

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