After seven years of planning, permits and construction, Antioch’s new water desalination plant will provide East County’s largest city with enough drinking water for generations to come. It is the first desalination plant for the Delta and only the second desalination plant in the Bay Area, along with a plant located in Newark. … The facility will produce up to six million gallons per day of treated drinking water — an important boost to regional supply reliability amid rising salinity in the San Joaquin River, the state said in a press release.