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Clean Air Act

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DENVER – Air quality rules in the Four Corners area will remain largely unchanged after requests for a review of the Environmental Protection Agency’s pollution-limiting regulations were denied in the 10th Circuit Court of Appeals April 14.

The Arizona Public Service, primary owner and operator of Four Corners Power Plant, contended that EPA regulations concerning the plant’s air emissions were too stringent, while a coalition of environmental and Native groups asserted they were too lax.

The coal-fired power plant, located in northwestern New Mexico on the Navajo Reservation, has been the subject of controversy among citizens’ groups and in neighboring Colorado, where state government officials have expressed concern about the health effects of air pollution drifting northward.

The coalition asking the court to review EPA’s plan to control air quality included the Sierra Club, Diné CARE, C-Aquifer for Diné and San Juan Citizens Alliance.

The EPA-approved New Mexico state plan for limiting pollutant emissions did not apply to the power plant because it’s located on Navajo tribal land. Because the Navajo Nation did not submit a tribal plan, the EPA proposed a plan under its tribal authority rule that essentially federalized and enhanced the state plan.

Unlike the original state standards, the EPA plan limited the emission of specific pollutants and the opacity, or cloudiness, of emissions, which can indicate whether pollution control equipment is functioning properly. The plan also said that limits applied during periods of malfunction, provisions to which APS objected as overly restrictive.

Environmentalists and tribal groups, on the other hand, maintained the emissions controls should be more stringent, designed according to state-of-the-art methods, and embodied in a new plan that would further restrict pollutant emissions.

Defending its pollution control plan for the power plant, EPA said tribes are generally in the early stages of developing air planning expertise, and the agency’s Clean Air Act strategy is a “multi-pronged” approach that may involve EPA/tribe joint planning or simply adopting an “average” federal plan to apply to all states.

Regulated pollutants at the power plant include sulfur dioxide, particulate matter and nitrogen oxide, the latter constituting “the largest single nitrogen oxide source in the United States,” according to Colorado state Rep. Scott Tipton, R-Cortez, in a letter March 9 to the state attorney general.

The power plant’s “dangerous emission levels of nitrogen oxide have created a permanent haze above Mesa Verde and the surrounding areas,” he said. “The National Park Service has reported that the haziest days at Mesa Verde have worsened over the past 10 years.”

He said ground-level ozone and fine particle pollution from power plant emissions create health hazards.

“It is past time that we cleaned up the Four Corners Power Plant, one of the largest sources of air pollution in the country, so that we can reduce ozone, people can breathe easier, and we can improve our western vistas towards what they used to be and should be,” Colorado Gov. Bill Ritter said in a March 16 press release, as he and the state attorney general joined the controversy.

The Four Corners Power Plant emits more than 40,000 tons of ozone-causing pollution annually, the release states.

Matt Kenna, of the Western Environmental Law Center, Durango, Colo., who represented the environmental/tribal groups, said that under the appellate court’s decision, at least current limits were upheld.

However, the ruling “seems to give EPA more flexibility on Indian lands than on non-Indian lands” and it appears that the Clean Air Act itself is “not as stringent for Indian country as elsewhere.”

In a related action, EPA is expected to revise its rule on dust not emitted by the power plant, but that comes off the plant site.