Calleguas Municipal Water District, a water wholesaler, serves about 75 percent of Ventura County's population. Calleguas ships state water from the Delta to Oxnard, Port Hueneme, and Camarillo on the Oxnard Plain and Moorpark, Thousand Oaks, Simi Valley and unincorporated areas in the east county. These areas also use groundwater and surface water supplies but these sources have increased in salinity. The source of the salts is a combination of agricultural, industrial, and residential activities in conjunction with salts in the imported water. The United Water Conservation District funded a detailed feasibility study in 2014 and found that the impaired groundwater in the south Oxnard Plain is suitable for treatment by reverse osmosis at an acceptable recovery range of 72 to 80 percent. Many local agencies, particularly those in the Calleguas Creek Watershed, have built or are putting in desalters to treat salty groundwater. The treated water can be used for drinking supplies which will make the region less dependent on imported state water. The remaining salt concentrate will be sent out to sea through the Calleguas Regional Salinity Management Project. This $220 million pipeline project started in 2003 and stretches from the marine outfall into Simi Valley. That pipeline services desalters in Simi Valley, Moorpark and the Camrosa Water District in the Santa Rosa Valley.