The Coronado power plant near St. Johns is one of three coal-fired stations affected by the federal mandate.


PHOENIX - The Arizona Corporation Commission is criticizing recent actions by the U.S. Environmental Protection agency to clean up the state's power plants.

The commission voted Tuesday to file a brief in federal appeals court supporting the state's challenge to pollution-control upgrades at three coal-fired power plants.

The EPA partially approved Arizona's air-quality plan for the Cholla, Coronado and Apache generating stations. But the agency set its own limits for nitrogen oxide emissions and gave the plants' operators five years to comply. The Apache plant is operated by the Arizona Electric Power Cooperative in Cochise. The Cholla plant in Joseph City, east of Flagstaff, is operated by Arizona Public Service Co. The Coronado plant is operated by Salt River Project near St. Johns.

The commission says the EPA's decision doesn't strike the right balance of environmental stewardship and protection of Arizona's economy.

The commission says it also will weigh in against a proposal for pollution-control upgrades at the Navajo Generating Station, which is operated by Salt River Project for a consortium of utility owners including Tucson Electric Power Co. Public comments are due Aug. 5.