Obstacles to research
Previously, the EPA had only looked briefly at fracking. In 2004, the agency published a study examining how the technique affected water supplies. It focused only on drilling for coalbed methane, however, whereas much of today's drilling is for gas or oil that's locked up in tight sands or shales. The study detailed concerns about the possibility of dangerous fluids migrating underground. But then, in an abrupt turn, it concluded that hydraulic fracturing "poses little or no threat" and "does not justify additional study." The one exception, that study found, was when diesel fuel (one of the sources of benzene) was used -- a practice the industry said it was discontinuing.

The EPA's 2004 findings were criticized in some scientific circles and by EPA whistleblower Wes Wilson, a recently retired environmental engineer who spent 36 years overseeing oil and gas industry impacts in the Rocky Mountain region. Wilson dismissed the study as "bogus." Although it included complaints about water problems from a handful of people, the EPA never tested their water or investigated their cases. Instead, the agency trusted the answers it received from state regulators. The study's final version was reviewed by a peer board that included former employees of BP, Halliburton and other oil and gas companies.

Politicians who supported the industry had tried for years to exempt fracking from the Safe Drinking Water Act, the 1974 law that regulates the injection of waste and chemicals underground. The EPA's 2004 study was used to justify that effort. With the help of then-Vice President Dick Cheney -- the former head of Halliburton -- President George W. Bush's landmark energy legislation, the 2005 Energy Policy Act, included a provision that prohibited the EPA from regulating fracking under the Safe Drinking Water Act. Regulation would be left to the states, many of which had underfunded agencies, looser standards and less manpower than the federal government.

EPA scientists were subtly pressured to cooperate, according to one former agency official. "The administration did not want us to take a formal position of opposition to the exemption," says Ben Grumbles, the EPA's assistant administrator at the time. The EPA never intended that its study would justify a broad legal exemption for fracking, Grumbles, now president of the Washington, D.C.-based Clean Water America Alliance, says. "We never construed it as a clean bill of health (for fracking)."

Nevertheless, the industry paraded the 2004 study as if it proved that water contamination could not be linked to the drilling process. "It shows there is no need for concern," says Doug Hock, an EnCana spokesman in Colorado. The case was closed: Fracking was safe, and the "Halliburton Loophole," as the exemption came to be called, effectively discouraged anyone in the EPA from considering what it might be doing to the environment.

"That door was nailed shut," says Oberley. "We absolutely do not look at fracking as an injection activity under the Safe Drinking Water Act. It's not done."

Other obstacles prevented the EPA from doing new research. The chemicals used in fracking -- the compounds that scientists would have to look for if they were to test water for contamination -- are mostly kept secret. Industry claims the information is proprietary, akin to Coca-Cola concealing its recipes from Pepsi. The trade names of the concoctions -- ZetaFlow, for example -- are disclosed, along with a statement of health risk intended for worker safety, called a Material Safety Data Sheet. But the exact chemicals and proportions that go into them remain a mystery.

That forces scientists to do a lot of guesswork. "We don't really know what those things that we should be looking for are," says Oberley. "That's been kind of an issue all along. ... The service companies haven't been fully disclosing to EPA what those constituents are."

The secrecy shocked Louis Meeks. How could everyone be so sure that gas drilling hadn't ruined his water if no one knew what chemicals were being used? Trying to figure it out was like shooting at a target blindfolded in the middle of the night. Yet Meeks was determined, and in October 2007, he paid an engineering firm $4,400 to test his water. A lab in Virginia analyzed it for an array of pollutants and found not only abnormal levels of chloride, iron and total dissolved solids, but also glycols, chemicals used in antifreeze -- and in gas wells.

That's when Meeks stopped wondering if he was crazy.