ALBUQUERQUE — Environmentalists and Navajo groups who have been fighting a proposed coal-fired plant on tribal land in northwestern New Mexico have appealed an air permit granted for the plant.

The petition filed Thursday alleges the U.S. Environmental Protection Agency failed to complete required analyses of the project, and instead was stampeded into granting the permit because developers of the Desert Rock power plant filed a lawsuit contending the EPA was taking too long.

The petition to the EPA's Environmental Appeals Board in Washington, D.C., asks that the permit be withdrawn and that the EPA be required to complete the analyses.

The groups contend those analyses would either lead to the denial of the permit or would require significant changes to it. They also want an extension of time, until Oct. 17, to document what they say are major problems with the permit. Currently they have until Sept. 2 to document concerns.

"The EPA is abandoning its mission by rushing a permit out the door for political expedience and ignoring the fact that it will emit massive quantities of CO2 and other pollutants," Earthjustice attorney Nick Persampieri, who filed the appeal, said in a statement.

Diné Power Authority and Houston-based Sithe Global Power are partners in building the 1,500-megawatt plant southwest of Farmington. The air permit was considered a major hurdle, although an environmental impact statement also must be approved before construction can begin.

Spokesmen for Desert Rock and the Navajo Nation said they expected the appeal.

"It's the same kind of tired arguments they've made for over two years now," Desert Rock spokesman Frank Maisano said. "They're misconstrued, they're misleading and in some cases they're just plain wrong."

The plant will reduce carbon emissions compared to a typical plant and will reduce water use by 85 percent from a typical plant, Maisano said.

"This is the most strict permit that EPA has ever issued," he said.

George Hardeen, spokesman for Navajo President Joe Shirley Jr., said the Diné Power Authority and the tribe have been waiting for the EPA to issue the permit for four years, and that the opponents have had time to voice their concerns.

Hardeen also said pollution in the area could be eased if other power plants copied Desert Rock's design.

The state of New Mexico has alleged the EPA violated the federal Clean Air Act in issuing the permit and has said it will appeal. Marissa Stone, a spokeswoman for the New Mexico Environment Department, said Thursday the appeal will be filed by Aug. 30, the deadline.

The permit sets limits on emissions covered by the Clean Air Act, and the EPA has said it will set a new level of performance for coal-fired plants. The EPA, in a June consent decree, had agreed to act on the permit by the end of July in settling the lawsuit the developers of the $3 billion project filed against the agency.

Thursday's petition alleges the permit has major deficiencies that violate public health laws and federal clean air laws. The petitioners say the EPA failed to do an analysis for hazardous air pollutants; improperly analyzed whether the plant will violate ozone standards; failed to consider carbon dioxide emissions limits, the collateral impacts of mining or issues related to the region's scarce water supplies; and did not do required consultations over the plant's impact on endangered species.

Those failures and others risk the public health and the environment, undermine the permit process and deprive the public of its ability to comment on the permit's appropriateness, the petition claims.

EPA officials said earlier this month their process was thorough and involved comprehensive technical analyses that will ensure that pollution levels safeguard public health and the environment.

An EPA spokeswoman has said a review of the more than 1,000 mostly negative comments on the permit led to additional monitoring requirements.

Environmentalists say Desert Rock would overwhelm efforts by New Mexico and neighboring states to reduce greenhouse gases and that plant emissions would more than offset commitments to cut pollution from other sources nearby.

Shirley has hailed the EPA's permit decision as much-needed to improve conditions on the reservation across parts of Arizona, New Mexico and Utah. He has said Desert Rock's benefits — including $50 million in annual revenues to the tribe and thousands of jobs — outweigh environmental concerns.

The petition was filed by the Sierra Club, Diné CARE, San Juan Citizens Alliance, Grand Canyon Trust, WildEarth Guardians, Environmental Defense Fund and Natural Resources Defense Council.