Work on the 189,000 m³/d Carlsbad seawater reverse-osmosis desalination plant is expected to start early in 2013, following approval by the board of the San Diego County Water Authority (SDCWA) on 29 November 2012 of the water-purchase agreement between SDCWA and Poseidon Resources, developers of the desalination plant.
The agreement clears the way for the sale of bonds next month to finance the fully permitted project, which includes the plant as well as a 10 mile (16 km) pipeline to deliver treated water to customers. Start-up is anticipated by the end of 2015, and the plant is expected to be in commercial operation early in 2016.
The desalination plant will produce 48,000 to 56,000 acre-ft (59‑69 million m³) of desalinated seawater annually, roughly one third of all water generated in San Diego County. Two SDCWA member agencies, Vallecitos Water District and Carlsbad Municipal Water District, will purchase a combined total of 6,000 acre-ft (7.4 million m³) of the desalinated water as their own local supply under separate agreements with the water authority.
Under the agreement, the total price for the desalinated water – including related upgrades to the Water Authority’s pipelines and treatment plant – is projected to start between US$ 2,041 and US$ 2,290 per acre-foot (US$ 1.65‑1.86/m³) in 2012 dollars, depending on how much is purchased annually. The purchase agreement says the price of water from Poseidon can only be adjusted for inflation and certain predefined circumstances.