Many of the nearly 270,000 oil and natural gas wells drilled in the West since 1980 have employed hydraulic fracturing, a process that involves the underground injection of tens of thousands to six million gallons of water per well. The water is laced with toxic chemicals and sand or other material known as “proppant.”
The fluid creates fractures in underground formations and the proppant holds these fractures open, allowing oil and gas to flow up the drilling pipe (EPA Fracturing Final 2004 ES-11, Schein 2008, Burnett and Vavra 2006). EPA considered hydraulic fracturing as exempt from the Safe Drinking Water Act following the act’s passage in 1974 (LEAF v. EPA 1997, EPA Fracturing Final 2004).
The act sets standards and requires permits for the underground injection of hazardous substances so that these materials do not endanger Underground Sources of Drinking Water (SDWA 2008).
According to 2005 Congressional testimony by the Interstate Oil and Gas Compact Commission, a group that represents governors from oil and gas producing states, hydraulic fracturing is used in 90 percent of all oil and natural gas wells drilled in the U.S. (IOGCC Carrillo 2005).
Hydraulic fracturing has recently been associated with water contamination and human health problems. Last summer, the federal Bureau of Land Management documented benzene contamination in water wells in Sublette County, Wyoming, the site of one of the nation’s largest natural gas fields.
Hydraulic fracturing is common in Sublette County (Lustgarten 2008). It was not clear what caused the contamination, but benzene is injected underground in hydraulic fracturing, and the extraction process also causes naturally occurring deposits of benzene to surface (Hess 1998, EPA Final 2004 4-11). What makes the situation so alarming is that there is no other likely source for the benzene in rural Sublette County other than natural gas operations.
Also last year, a nurse in Durango, Colorado almost died after being exposed to hydraulic fracturing chemicals (Hanel 2008).
In a draft 2002 report, EPA reported that at the point of injection, nine hydraulic fracturing chemicals violated water quality standards (EPA Fracturing Draft 2002). This assertion was edited out before the final report was published. The published report did note that fracturing fluids are likely to remain underground and are “likely to be transported by groundwater supplies” (EPA Fracturing Final 2004).
In a 1997 case involving hydraulic fracturing of coalbed methane (CBM) wells, the 11th Circuit Court of Appeals ruled that the Safe Drinking Water Act’s underground injection standards applied to hydraulic fracturing. EPA conducted a study and, in a report that was heavily criticized by an internal whistle-blower and others, concluded that “the injection of hydraulic fracturing fluids into CBM wells poses little or no threat” to drinking water (EPA Fracturing Final 2004 ES-16).
The agency suggested that it was up to states with primary authority to enforce the Safe Drinking Water Act to set standards for any hydraulic fracturing that might threaten underground sources of drinking water (EPA Fracturing Final 2004 ES-17). In 2005, Congress exempted most hydraulic fracturing from the Safe Drinking Water Act but said the act would apply to fracturing with diesel fuel (SDWA Exemption 2005).
Environmental Working Group