Oil and natural gas companies have drilled almost 120,000 wells in the West since 2000, mostly for natural gas, and nearly 270,000 since 1980, according to industry records analyzed by Environmental Working Group. Yet drilling companies enjoy exemptions under most major federal environmental laws.

Oil and natural gas operations have industrialized the Western landscape, punching thousands of wells on pristine lands, injecting toxic chemicals, consuming millions of gallons of water, clawing out pits for their hazardous waste and slashing the ground for sprawling road networks. Every well carries with it the potential for serious environmental degradation.

Number of oil and gas wells drilled (1980-2008*)

* NOTE: Data for 2008 not complete, data for Chaves, Eddy, Lea and Roosevelt Counties in New Mexico not complete. See methodology in text of report.

Yet as drilling has intensified over the past decade, federal environmental protections have dwindled. Unlike most other industries, oil and gas drillers enjoy waivers under the Safe Drinking Water Act, Clean Water Act, Clean Air Act, Resource Conservation and Recovery Act, Superfund, the Emergency Planning and Community Right to Know Act and the National Environmental Policy Act.

Companies regularly complain that environmental standards deny them access to drilling sites. But the cratered landscape tells a different story.

Environmental Working Group's analysis of industry records obtained from IHS, an Englewood, Colorado-based energy data company, shows that 99 percent of Western oil and gas drilling since 1980 has concentrated in six states: California, Colorado, Montana, New Mexico, Utah and Wyoming. Across the West, 25 counties accounted for 77 percent, or more than 200,000, of the wells drilled since 1980.

Counties with the most wells drilled (1980-2008*)

* NOTE: Data for 2008 not complete, data for Chaves, Eddy, Lea and Roosevelt Counties in New Mexico not complete. See methodology in text of report.

The Environmental Protection Agency and other government agencies have found that oil and gas drilling is a source of air pollution, a generator of hazardous waste and a potentially huge source of toxic wastewater (EPA 2000, EPA FR 1988). As oil and gas drilling proliferates, it presents an exponential threat to the environment, particularly precious western water supplies.

Drilling is likely to explode again when oil and gas prices resume their upward spiral. Before that happens, federal laws must be reformed, with far more stringent standards to prevent pollution from oil and gas drilling operations. Otherwise, millions of acres of Western lands and untold surface and underground waters may be irreparably damaged.

With this interactive report, readers can pinpoint drilling on a county-by-county basis. The report highlights many instances of industry pollution and underscores significant gaps in laws.

For a county-by-county breakdown and maps of drilling in 12 Western states, click on the state links in the featured table above.

Among the key findings:

• The U.S. Bureau of Land Management recently documented toxic benzene contamination in groundwater in Sublette County, Wyoming, where 3,258 wells were drilled between 2000 and 2008 (Lustgarten 2008). (Just 1,410 wells were drilled there during the previous two decades.) 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. Sublette County is rural making it unlikely that the benzene came from a source other than drilling (EPA Final HF 2004, Hess MSDS 1998, EPA Benzene 2008). Yet Congress and EPA have exempted hydraulic fracturing from the Safe Drinking Water Act that sets standards for underground injection of toxic chemicals (SDWA 2008).
• Last year, a nurse in LaPlata County, Colorado, almost died from contact with the clothing of a worker she had treated. The worker's clothes were permeated with a chemical fluid used in natural gas drilling. The company that made the fluid refused to identify it, citing trade secrets to the nurse's physician even as he was laboring frantically to save her life (Hanel 2008). Disclosure is generally required under the federal Emergency Planning and Community Right to Know Act, but Congress has exempted the oil and gas industries (EPCRA CFR 2008).
• The New Mexico Oil Conservation Division has identified more than 400 cases statewide of groundwater contamination from oil and gas waste pits. Many of the cases were located in San Juan County, New Mexico, where companies drilled more than 11,000 wells between 1980 and 2008 (Prukop 2008, Farmington 2008). Yet oil and gas industry wastes are exempted from the federal Resource Conservation and Recovery Act that sets standards for handling of hazardous wastes (RCRA 2008).

In the absence of federal oversight, New Mexico and Colorado have passed tough new standards designed to minimize pollution from oil and gas drilling, but industry is attempting to roll back these protections. State standards often do not close the loopholes under federal law.

Some members of Congress have proposed closing the oil and gas industry's environmental loopholes. Last year, Reps. Diana DeGette (D-CO), Maurice Hinchey (D-NY) and John Salazar (D-CO) introduced legislation to repeal the exemption under the Safe Drinking Water Act for hydraulic fracturing, a process pioneered by Halliburton in which oil and gas companies inject toxic chemical-laced water – as many as 6 million gallons per well -- to enhance production.