The Orange County Water District Ground Water Replenishment System is the largest advanced water treatment plant in the world for groundwater recharge. Since it was commissioned, it has produced 445.8 billion gallons of water to serve 1 million people. That amounts to 130 million gallons per day that is treated through microfiltration, reverse osmosis and ultraviolet disinfection. Mehul Patel, executive director of operations for the OCWD GWRS, took WaterWorld editors on a tour of the plant to share how it is bolstering Orange County’s water supplies through water reuse.