The Four Corners Power Plant along with its operator Arizona Public Service Co. and owners, including Salt River Project, have been named in a lawsuit by several groups alleging the plant violates the federal clean air laws. The lawsuit, filed Tuesday by Earthjustice on behalf of several Navajo groups and other environmental groups, is seeking to force measures to clean up the coal power plant to reduce emissions. â¿¿Four Cornersâ¿¿ excessive pollution poses a serious threat to our communityâ¿¿s health,â¿ said Nicole Horseherder of Toâ¿¿ Nizhoni Ani, one of the groups involved in the lawsuit. â¿¿Four Cornersâ¿¿ owners have two options if they are going to obey the law: Clean the plant up, or shut it down.â¿ While APS operates the plant and owns all three generating units and part of two others along with SRP, Public Service Co. of New Mexico, Tucson Electric Power and El Paso Electric. At more than 2,000 megawatts of production, it is one of the largest coal-powered plants in the U.S. APS announced a year ago it was buying out Southern California Edisonâ¿¿s share in two of the units and closing the three oldest units, which had been considered a source of pollution in the Four Corners region, which comprises northeastern Arizona, northwestern New Mexico, southwestern Colorado and southeastern Utah. SRP spokesman Scott Harelson said the utility stands behind APSâ¿¿ statements that the plant is not violating the federal Clean Air Act. The utility has not seen the lawsuit, but two notices of claim have been filed against the plant by the same groups. A notice of claim must be filed before a lawsuit can proceed. The lawsuit was filed within the U.S. District Court of New Mexico and alleges pollution from the plant has contributed to myriad health problems in the Four Corners region. Among the plantiffs are Toâ¿¿ Nizhoni Ani and Dine Citizens Against Ruining Our Environment, the Sierra Club and the National Parks Conservation Association.