The feds wake up
Hydraulic fracturing was first used commercially in 1949 by Halliburton, one of the world's largest oilfield service companies. Over the years, the process has been revamped to achieve more effective combinations of chemicals and pressure, enabling drillers to tap gas in ever-deeper and more challenging formations. In 1995, fracking was used in only a small percentage of gas wells, but by 2008, it was being used in nine out of 10 of the roughly 32,000 wells drilled in the U.S. each year. As the technology made it possible to reach resources that had been inaccessible, estimates of the nation's gas reserves jumped by two-thirds. Thirty-one states were being drilled in 2008, and geologists claimed the nation contained enough natural gas to supply its needs for a century.

"Hydraulic fracturing is one of the U.S. oil and gas industry's crowning achievements," says Lee Fuller, vice president of government affairs for the Independent Petroleum Association of America and an influential lobbyist who helped shape federal fracking policy. Fracturing, Fuller says, takes place "with surgical precision and unrivaled environmental safety records."

In recent years, the gas rush has spread from the Interior West to Arkansas and Louisiana and the Marcellus Shale formation in Pennsylvania, Maryland and upstate New York. Forests are checkered with five-acre pads cleared for wells and compressor stations. Tens of thousands of trucks deliver water for the various drilling processes and remove the polluted wastewater. Some state governments require drill rigs to be at least 150 feet from homes -- not out of any environmental concern, but because that's the distance necessary to protect a house should a typical 15-story, 1,200-horsepower rig topple over. A gas field is a huge landscape-scale factory, says Erik Schlenker-Goodrich, a New Mexico staffer for the Western Environmental Law Center, "just without a roof."

With hundreds of these factories ramping up production, reports of problems began to emerge.

In Clark, a small northern Wyoming town, benzene -- one of the chemicals used in fracking and other gas-well processes -- was detected in an aquifer after a well blowout. In central Colorado, near the town of Silt, a water well's cap blew off and started spewing nasty water just as gas wells were being fracked nearby. A few miles away, methane gas began bubbling up out of a placid eddy in a Colorado River tributary; then high levels of benzene were found. It was difficult to say what caused each of these incidents, but gas drilling and the close proximity of hydraulic fracturing were a common thread.

In Pavillion, Donna Meeks, who works as a bookkeeper for the Fremont County School District, learned that a co-worker had similar problems at home. Rhonda and Jeff Locker were battling illnesses that they suspected were caused by water contamination. Years earlier, before it was bought by EnCana, the Tom Brown gas-drilling company had paid for a water-filtration system in the Lockers' house. Though the Lockers lived just a short way down the road, the two families -- with typical Western taciturnity -- had never spoken to each other about their problems. "We weren't real open about our concerns," Jeff Locker says. "It's kind of like talking about your medical conditions."

If state and federal environment regulators addressed these incidents at all, they saw them as isolated problems, possibly related to longtime risks that gas wells might suffer various kinds of leaks, not symptoms of an emerging larger threat from the increased use of fracking. Regulators in different states rarely compared notes, and anecdotal stories were confined to local press reports and never thoroughly investigated. The dots were not connected.

Not, that is, until a problem emerged 90 miles west of Pavillion, in Sublette County, another wind-raked, sparsely populated area that overlies a deeply buried dome of gas-rich sandstone known as the Pinedale Anticline. In 1999, the Pinedale drilling field had fewer than 35 producing wells. By 2008, there were more than 1,100, and EnCana, Shell, BP and other companies were lining up to drill 4,400 additional wells on the ocean of sagebrush stretching across the county.

Much of the land in Sublette County is owned by the federal government, which meant that the Environmental Protection Agency -- rather than just state regulators -- had to conduct an environmental review before the new drilling could begin. As part of that review, in 2007 EPA hydrologists sampled a once-pristine aquifer that underlies the region. What they found was shocking: high levels of benzene, a known carcinogen, in 88 samples taken across 28 miles.

"It was like, holy shit, this is huge," says Greg Oberley, a groundwater specialist at the EPA's Region 8 headquarters in Denver. "You've got benzene in a usable aquifer, and nobody is able to verbalize well, using factual information, how the benzene got there. Nobody understood what caused this."

In the past, water contamination in drilling fields had been blamed on outdated practices -- the messy mistakes of the 1950s. But most of the drilling around Pinedale was relatively new, and it seemed that any contamination linked to drilling also had to be linked to contemporary practices.

For perhaps the first time, the federal officials were alarmed. Oberley was among a small group of EPA scientists -- mostly based in Denver -- who wanted to begin fresh research into what was causing water pollution near drilling fields.

The stakes were high: Policy-makers -- even prominent environmental groups like the Sierra Club -- were championing natural gas as a fuel for power plants, because it burns cleaner than coal and produces fewer climate change-causing emissions. A natural-gas plant can emit as little as half the greenhouse gases that a coal plant does to generate the same amount of electricity, although that calculation doesn't include carbon emissions from gas fields, coal mines and other aspects of fuel gathering and processing.

If the EPA's scientists concluded that gas drilling posed a serious threat to water quality, it could have huge implications. Many of the urban and rural areas close to drilling zones get their water from aquifers, and 15 percent of Americans rely on private wells for domestic water. Private wells are not routinely tested for pollutants from drilling or any other industry, and there are no federal regulations to ensure their safety. Contaminants could also affect surface water supplies that supply drinking and irrigation water to millions of people.

"Are the problems we're seeing an anomaly? Or is the current regime (of gas drilling) with new fields and new practices compromising groundwater quality on a widespread, wide-scale basis?" wonders one senior EPA staff person, who declined to be named because the issue is so politically charged. "That's a question that we really don't have answers to. We have anecdotal reports. The weight of evidence, it's adding up."

Oberley realized that the issue required thorough, objective and time-consuming study. "For EPA to walk into industry's offices and say, 'You need to change this,' we have to have some pretty good data to back that up," Oberley says. "Because they're not going to respond to innuendo or insinuation that there's a problem."