Operations have begun at the Carlsbad Desalination Plant, the result of a 30-year water purchase agreement between plant developer and owner Poseidon Water and the San Diego County Water Authority for production of up to 56,000 acre-feet of water per year, enough to meet the needs of about 400,000 people. The plant uses RO to produce approximately 10 percent of the region’s water supply; it’s a core supply regardless of weather conditions and is blended with water from other sources for regional distribution. Desalinated water will cost typical homeowners in the region about an additional $5 per month, in line with the low end of projections when the project was launched in late 2012. The costs are already factored into the Water Authority’s 2016 rates.