Officials in Three States Pin Water Woes on Gas Drilling

Norma Fiorentino's drinking water well was a time bomb. For weeks, workers in her small northeastern Pennsylvania town had been plumbing natural gas deposits from a drilling rig a few hundred yards away. They cracked the earth and pumped in fluids to force the gas out. Somehow, stray gas worked into tiny crevasses in the rock, leaking upward into the aquifer and slipping quietly into Fiorentino's well. Then, according to the state's working theory, a motorized pump turned on in her well house, flicked a spark and caused a New Year's morning blast that tossed aside a concrete slab weighing several thousand pounds.

Fiorentino wasn't home at the time, so it's difficult to know exactly what happened. But afterward, state officials found methane, the largest component of natural gas, in her drinking water. If the fumes that built up in her well house had collected in her basement, the explosion could have killed her.

Dimock, the poverty-stricken enclave where Fiorentino lives, is ground zero for drilling the Marcellus Shale, a prized deposit of natural gas that is increasingly touted as one of the country's most abundant and cleanest alternatives to oil. The drilling here -- as in other parts of the nation -- is supposed to be a boon, bringing much-needed jobs and millions of dollars in royalties to cash-strapped homeowners.

But a string of documented cases of gas escaping into drinking water -- not just in Pennsylvania but across North America -- is raising new concerns about the hidden costs of this economic tide and strengthening arguments across the country that drilling can put drinking water at risk.

Near Cleveland, Ohio, an entire house exploded in late 2007 after gas seeped into its water well. The Ohio Department of Natural Resources later issued a 153-page report [1] (PDF) that blamed a nearby gas well's faulty concrete casing and hydraulic fracturing [2] -- a deep-drilling process that shoots millions of gallons of water, sand and chemicals into the ground under explosive pressure -- for pushing methane into an aquifer and causing the explosion.

In Dimock, several drinking water wells have exploded and nine others were found with so much gas that one homeowner was told to open a window if he planned to take a bath. Dishes showed metallic streaks that couldn't be washed off, and tests also showed high amounts of aluminum and iron, prompting fears that drilling fluids might be contaminating the water along with the gas. In February, the Pennsylvania Department of Environmental Protection charged Cabot Oil & Gas with two violations that it says caused the contamination, theorizing that gas leaked from the well casing into fractures underground.

Industry representatives say methane contamination incidents are statistically insignificant, considering that 452,000 wells produced gas in the United States last year. They also point out that methane doesn't necessarily come from gas wells -- it's common in nature and can leak into water from biological processes near the surface, like rotting plants.

The industry also defends its construction technology, saying it keeps gas and drilling fluids -- including any chemicals used for hydraulic fracturing -- safely trapped in layers of steel and concrete. Even if some escapes, they say, thousands of feet of rock make it almost impossible for it to migrate into drinking water aquifers. When an accident happens, the blame can usually be traced to a lone bad apple -- some contractor who didn't follow regulations, they say. Those arguments helped the gas drilling industry win rare exemptions from the Safe Drinking Water Act and the Clean Water Act when Congress enacted the 2005 Energy Policy Act [3].

But now an exhaustive examination of the methane problem in western Colorado is offering a strong scientific repudiation of that argument. Released in December by Garfield County, one of the most intensely drilled areas in the nation, the report concludes that gas drilling has degraded water in dozens of water wells [4] (PDF).