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Boom in gas drilling fuels contamination concerns in Colorado

Some scientists and citizens want firms that extract natural gas to reveal what chemicals they’re using.

By Josh McDanielContributor of The Christian Science Monitor / February 5, 2009

Natural gas development at the base of the Roan Cliffs near the town of Rifle, Colo.

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Grand Junction, Colo.

When Lisa Bracken noticed gas bubbling to the surface of Divide Creek, which runs along one side of her 60 acres in western Colorado, she suspected another gas “seep.” It had happened once before, in 2004, after faulty natural-gas drilling in the vicinity contaminated the creek with benzene and methane.

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Her concern, though, is not confined to the small waterway. Her cottonwood and pinyon trees are dying, along with parts of meadowland that her family manages for wildlife, and Ms. Bracken believes the likely culprit is methane seepage stemming from one or more of the 11 natural-gas wells within a mile of her property – though independent investigations have not been able to prove a link.

“It is so frustrating to watch the land die,” she says. Bracken does not think the current drought is responsible. “We have seen it go through drought cycles, but nothing like this. The land has lost its ability to sustain itself.”

Her concern and that of others is putting new scrutiny on a drilling practice knows as “fracing,” short for hydraulic fracturing.

A common component of natural-gas extraction worldwide, fracturing operations inject water, sand, and a cocktail of chemicals at high pressure into rock formations thousands of feet below the surface, opening existing fractures in the rock and allowing gas to rise through the wells. The practice makes drilling possible in areas that 10 to 20 years ago would not have been profitable, including parts of Colorado, which accounts for 6.2 percent of natural-gas produced in the US.

The concerns center mainly around the injected fluid. Most comes back to the surface, but 30 to 40 percent is never recovered, according to industry estimates.

The composition of hydraulic fracturing fluids is proprietary, and energy companies are vehement about the need to keep the contents secret to protect their competitive edge. That confidentiality is protected by the federal Energy Policy Act of 2005, which exempted hydraulic fracturing from regulation under the Safe Drinking Water Act.

“We now use five to 10 ‘frac’ jobs per well, with up to 100 million gallons of fluid used per frac,” says geologist Geoffrey Thyne of the University of Wyoming, whose analysis of the large gas fields around Divide Creek found elevated methane and chloride levels in groundwater samples.

“They are injecting fluid that may or may not be hazardous into thousands of wells and not recovering all of it. We have to ask, what is in those fluids and where does the fluid go?” says Mr. Thyne.

Theo Colborn, a leading researcher on the effects of toxins on the human endocrine system, has been trying to glean what is in the injection fluid.

Preliminary results of her study identify 65 chemicals that are probable components. She is urging that groundwater sampling be expanded to determine whether these chemicals or their byproducts are showing up in areas where hydraulic fracturing is being used.

“We know less and less about what chemicals are being used, but the ones that we do know are being used are very dangerous,” says Dr. Colborn.

Chemicals such as benzene, glycol-ethers, toluene, 2-(2-methoxyethoxy) ethanol, and nonylphenols were used in the fracturing fluids, her study found – all of which have been linked in previous research to health disorders when human exposure is too high.

Pushing for legislation
Colborn’s work and complaints from residents living near drilling operations are spurring policymakers to take a closer look at hydraulic fracturing. US Reps. Diana DeGette (D) and John Salazar (D), both of Colorado, have introduced legislation that would repeal the Safe Drinking Water Act exemption for hydraulic fracturing and force energy companies to reveal the contents of the fracturing fluids.

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