Eliminating once-through cooling with seawater at three major coastal power plants remains a wild card for Los Angeles Department of Water & Power ratepayers, a Los Angeles City Council committee learned Dec. 6. The cost of eliminating once-through cooling at the plants by 2029 remains at least partly unknown, but \u201cis a very expensive proposition,\u201d Andrew Rea, PA Consulting analyst, told the council\u2019s Energy & Environment Committee. Rea also said under the department\u2019s current phase-out plan it\u2019s uncertain whether it can actually meet the 2029 deadline. To do so, Rea suggested the muni likely would face accelerated costs that could prevent it from keeping its rates below those of investor-owned utilities. That\u2019s one of the publicly-owned utility\u2019s chief stated goals. The analyst presented PA Consulting\u2019s review of the muni\u2019s 2010 integrated resource plan to the committee. It suggested that under its current plan the muni could not comply with the state phase-out requirement until 2035. The muni\u2019s integrated resource plan lays out a long-term roadmap for how it plans to provide reliable power economically while meeting increasingly stringent environmental regulations. LADWP put the plan together when there was regulatory uncertainty regarding once-through cooling, said Michael Webster, LADWP assistant manager of system development and procurement. He said that as the resource plan is updated the department plans to more specifically outline how it intends to eliminate once-through cooling at all of its plants by 2029 and what it will cost to do so. The department\u2019s plan to end once-through cooling responds to regulations the State Water Resources Control Board adopted in 2010 (Current, May 7, 2010). After that, the LADWP earlier this year convinced the Water Board it could not afford to meet the original phase-out deadline of 2020 and needed an extension until 2029 (Current, July 22, 2011). The muni estimated it would cost $2 billion to meet the requirement. The Water Board adopted the rules under the federal Clean Water Act to protect marine life. Fish and other aquatic organisms are killed when they go through power plant cooling systems. They also die from thermal shock when the cooling systems discharge heat into the marine waters. LADWP\u2019s next integrated resource plan update--which should provide more detail on its plans to phase out once-through cooling and the associated cost--is due next year.