Jason Dadakis of the Orange County Water District talks about the water filtration system at their water treatment plant in Fountain Valley, Calif. In 2015 the facility expanded to produce 100 million gallons (375 million liters) of water each day. Chris Carlson, AP
California’s drought has spurred interest in treating wastewater for drinking. For decades, some areas of the state, notably Orange County, have resorted to indirect potable reuse – treating wastewater to drinking water standards, but then filtering it back underground to mix with groundwater before pumping it back out for drinking.
But now the State Water Resources Control Board, prompted by the legislature, has tasked a panel of experts with determining whether it is feasible to develop criteria for direct potable reuse (DPR) – where wastewater is treated for drinking and then piped directly to customers without first being mixed in a reservoir or groundwater aquifer.