Feb. 1 (Bloomberg) -- The U.S. Environmental Protection Agency released 622 documents related to its study of water contamination tied to hydraulic fracturing in Pavillion, Wyoming, as Republican lawmakers criticized the findings.

The EPA documents include sampling data and raw findings from laboratories. The agency also said that results from the study, which found elevated levels of benzene and said the chemicals found were consistent with those used in fracking, shouldn’t be used to judge the safety of fracking in Pennsylvania or other states on the Marcellus Shale formation, where the geography is different.

“Our analysis is limited to the particular geologic conditions in the Pavillion gas field,” Jim Martin, the EPA administrator for the region that covers Wyoming, testified today at a subcommittee hearing of the House Science Committee.

Environmental groups say fracking, in which millions of gallons of chemically treated water are forced underground to shatter rock and let gas flow, is a threat to drinking-water supplies. The EPA’s draft report on groundwater contamination in Pavillion, about 230 miles (370 kilometers) northeast of Salt Lake City, was the first to link the drilling technique to spoiling water. The EPA has moved to establish a peer-review panel to examine its findings.

Naturally Occurring Chemicals

The EPA is waiting for information from Encana Corp., which has 123 wells in that area, on the water samples the company took at the same time as the EPA, Martin testified. Encana has criticized the EPA’s results, and said the agency didn’t take into account naturally occurring chemicals.

Representative Andy Harris of Maryland, the Republican chairman of the Energy and Environment subcommittee of the House Science Committee, criticized Martin and the EPA, saying that the study of groundwater contamination was an example of “politics trumping policy and advocacy trumping science.”

“While I am pleased that the EPA posted 622 documents last night, it is unfortunate that this transparency appears to only have been compelled by the calling of a congressional oversight hearing,” Harris said.

The committee hearing was delayed as a documentary filmmaker was handcuffed by police and removed from the room. The committee rules say only accredited media are permitted to film hearings. Democrats failed in a party-line vote to delay the hearing until the filmmaker could gain accreditation.