GILLETTE - It happened when an oil and gas company was performing a "hydraulic fracture" on a natural gas well not too far from Laura Amos's Silt, Colo., home.

The family's water well blew.

"Fracturing created or opened a hydro-geological connection between our water well and the gas well, sending the cap of our water well flying and blowing our water into the air like a geyser at Yellowstone," Amos said. "Immediately, our water turned gray, had a horrible odor and bubbled like 7UP."

Hydraulic fracturing - or fracing - is a technique in which fluids are pumped into an oil or gas well at high pressure to fracture geologic formations and open up pathways for the oil or gas to flow to the well. The practice is widely used across the West and is credited for unlocking multibillion-dollar gas plays such as the one in the Greater Green River Basin.

Some allege the practice isn't properly regulated and say it could lead to contamination of underground drinking water supplies.

On Wednesday, the Oil and Gas Accountability Project conducted a nationwide teleconference announcing the release of its report, "Our Drinking Water at Risk." The report alleges that the Environmental Protection Agency's assessment of the risk of fracturing has major gaps, and the activity should be regulated under the Safe Drinking Water Act.

The report comes months after EPA whistle-blower Wes Wilson provided a report to the EPA inspector general alleging the agency had failed to follow its own scientific policy in assessing the risk. Wilson's report is being investigated.

"EPA's main conclusion was that hydraulic fracturing in coal-bed methane does not pose a threat to drinking water. The agency said further study of the issue is not warranted," said Lisa Sumi, author of OGAP's report.

EPA spokesman Dave Ryan said his agency only received OGAP's report on Wednesday and could not comment on allegations in the report until staff had an opportunity to thoroughly review it.

Wyoming's approach

The issue dates back more than 10 years, when hydraulic fracturing was being used in deep coal-bed methane gas fields in Alabama. Legal wrangling eventually forced the EPA to impose regulations on the activity under the Safe Drinking Water Act, which it did Alabama, but in not in any other state, according to OGAP.

In Wyoming, hydraulic fracturing has been regulated by the Oil and Gas Conservation Commission since the 1950s. OGCC Supervisor Don Likwartz said his staff discusses plans for fracturing when a company applies for a permit to drill. Companies are required to cement and otherwise seal specific portions of well bores so the fracturing fluids are contained and do not stray outside targeted structures.

Likwartz said if fracturing were to be regulated as an underground injection activity under the Safe Drinking Water Act in Wyoming, it would simply add another layer to the regulatory process.

"That requires a full hearing," Likwartz said. "They'd have to prepare the application plus all of the back-up information, and it would be heard by the examiners. But we already approve it."

Of all its operations in the world, most of Halliburton's hydraulic fracturing occurs in Wyoming, according to Likwartz. Schlumerberger and several other companies specialize in providing hydraulic fracture treatments in Wyoming.

In fact, fracturing is key to unlocking gas from thousands of wells south of Pinedale, according to Likwartz. He said each well in the region can require between 10 and 20 fracture treatments. Deep natural gas wells in the Wamsutter area require up to four fracture treatments.

Unlike in Alabama, hydraulic fracturing is not used in the Powder River Basin coal-bed methane fields in northeast Wyoming. However, it may be used in deeper coal seams in Wyoming as the development progresses in Carbon County and western areas of the state.

Rick Aluise, administrator for the town of Silt, Colo., said much of the concern about fracing is the chemicals that are sometimes used in the fluids and the health risks associated if the chemicals enter drinking water.

"This is not a laughing matter, it's not a joking matter, and it's not a matter about a company's bottom line. These are people's lives and health that we're dealing with here," Aluise said in the teleconference.

Energy reporter Dustin Bleizeffer can be reached at (307) 682-3388 or dzeffer@trib.com.