obtain permitted use of recycled water for groundwater recharge in 1962. Orange County is located in Southern California, USA, and houses a classic example in indirect potable reuse. A large-scale artificial groundwater recharge scheme exists in the area, providing a much-needed freshwater barrier to intruding seawater. Part of the injected water consists of recycled water, which started in 1976 with Water Factory 21, which used RO and high lime to clean the water (production capacity of 19,000 m3 per day). This plant was decommissioned in 2004 and has since made place for a new project with a higher capacity (265,000 m3 per day with an ultimate capacity of 492,000 m3 per day), under the name of Groundwater Replenishment System. The Irvine Ranch Water District (IRWD) was the first water district in California to receive an unrestricted use permit from the state for its recycled water; such a permit means that water can be used for any purpose except drinking. IRWD maintains one of the largest recycled water systems in the nation with more than 400 miles serving more than 4,500 metered connections. The Irvine Ranch Water District and Orange County Water District in Southern California are established leaders in recycled water. Further, the Orange County Water District, located in Orange County, water is given more advanced treatments and is used indirectly for drinking. The Trinity River in Texas is a representative example of an effluent-dominated surface water system where de facto potable water reuse occurs. The section of the river south of Dallas/Fort Worth consists almost entirely of wastewater effluent under base flow conditions. In response to concerns about nutrients, the wastewater treatment plants in Dallas/Fort Worth that collectively discharge about 2 million m3 per day of effluent employ nutrient removal processes. Little dilution of the effluent-dominated waters occurs as the water travels from Dallas/Fort Worth to Lake Livingston, which is one of the main drinking water reservoirs for Houston. Once the water reaches Lake Livingston, it is subjected to conventional drinking water treatment prior to delivery to consumers in Houston. Non-potable reuse (NPR) Austin, Texas Clark County, Nevada Clearwater, Florida Contra Costa County, California San Antonio operates the largest recycled water system in the United States. Tucson, Arizona San Diego, California (San Diego County) St. Petersburg, Florida Indirect potable reuse (IPR) Orange County is located in Southern California, USA, and houses a classic example in IPR. A large-scale artificial