Common method of drilling for gas may pose unregulated threats to underground water

More evidence is being discovered that suggests drilling for natural gas has signiifcant consequences for the environment. While the Environmental Protection Agency and the Bureau for Land Management have downplayed problems, an investigation by ProPublica reaches a different conclusion. The non-profit investigative journalism project "found that water contamination in drilling areas around the country is far more prevalent than the EPA asserts," Abrahm Lustgarten writes. (ProPublica photo)

The problems are closely associated with a process called hydraulic fracturing, the most pervasive method used in natural gas drilling. This process, invented by Halliburton, involves shooting "vast amounts of water, sand and chemicals several miles underground to break apart rock and release the gas," adds Lustgarten. A study done in 2004 by the EPA deemed the practice safe and Congress excluded hydraulic fracturing from federal water law.

In Sublette County, Wyoming, underlain by one of the largest gas fields in the U.S., water contamination appears to be linked to hydraulic fracturing. "In July, a hydrologist dropped a plastic sampling pipe 300 feet down a water well . . . and pulled up a load of brown, oily water with a foul smell," writes Lustgarten. "Tests showed it contained benzene, a chemical believed to cause aplastic anemia and leukemia, in a concentration 1,500 times the level safe for people."

So far the investigation by ProPublica has found more than 1,000 cases of pollution documented by courts and state or local governments. Not all involve underground contamination; some deal with surface issues such as "accidental spills and leaky tanks, trucks and waste pits allowed benzene and other chemicals to leach into streams, springs and water wells," Lustgarten reports. Over the last few years, however, a series of contamination incidents have raised new questions about the EPA study and chemicals used in hydraulic fracturing, which remain mysterious.

"It is difficult to pinpoint the exact cause of each contamination, or measure its spread across the environment accurately," Lustgarten writes, "because the precise nature and concentrations of the chemicals used by industry are considered trade secrets." Not even EPA knows the composition of the drilling fluids being used, he reports. (Read more)