With dwindling water supplies, cities throughout Arizona are exploring multiple ways to meet residents’ water needs. In March, the Arizona Department of Environmental Quality gave municipalities a new tool: Wastewater treated by advanced purification can now flow directly from local water systems into residents’ taps. For years, cities have used advanced purified water as an indirect potable source, recharging it into aquifers or other water supplies, and later extracting it for purification and human consumption. The new regulations enable cities to use advanced purified water immediately for direct consumption. Advanced purified water is wastewater that has undergone a multi-step process to remove impurities and meet state drinking water standards. The treatment uses ultrafiltration, reverse osmosis, ultraviolet light disinfection and advanced oxidation.