U.S. Environmental Protection Agency requirements that coal plants reduce smog-creating and other emissions have led to the closure of several aging plants in the West that serve California. The cost of installing pollution control equipment has made the plants uneconomic. Coal units in the West that have closed--or plan to--in response to EPA emissions regulations include: -Three of five units at the Four Corners plant are to shut down. The plant capacity is to drop from 2,100 MW to 1,540 MW. Southern California Edison was part owner but the combination of costly upgrades and state law pushed it to sell its share. In March, the California Public Utilities Commission approved the sale of Edison’s stake to Arizona Public Service. -The 585 MW Boardman coal plant in Oregon, owned by Portland General Electric that sends power to California, announced in 2010 it would cease operations in 2020. That is 20 years ahead of schedule. -The 1,800 MW Intermountain Power Project in Utah, which also serves the Los Angeles Department of Water & Power, looks slated to be converted to a natural gas fired plant. The Utah Legislature passed a bill this year authorizing the conversion (Current, Oct. 12, 2012). -The Mohave coal plant in Arizona closed in early 2006 because of federally-mandated emissions controls. That list may also include the 2,250 MW Navajo coal plant--or at least the LADWP’s 477 MW share. The muni announced last month it plans to sell its stake in the Arizona facility. Last August, EPA required the Navajo plant, the biggest in the West, to install emissions controls for particulate--with additional nitrogen oxide controls due soon. The curbs are particularly important to California if the plant’s electricity output doesn’t drop post-divestiture. Phone calls to some out-of-state utilities revealed there was scant interest in LADWP’s share. For example, a potential buyer, the Utah Municipal Power System, had no interest in investing in the project. The plant is “old and has problems,” noted Nathan Hardy, the muni’s director of power resources.