Los Angeles will soon begin building a $740-million project to transform wastewater into purified drinking water in the San Fernando Valley, expanding the city’s local water supply in an effort to prepare for worsening droughts compounded by climate change. … When completed, the facilities will purify treated wastewater and produce 20 million gallons of drinking water per day, enough to supply about 250,000 people. The drinking water that the plant produces will be piped 10 miles northeast to L.A. County’s Hansen Spreading Grounds, where it will flow into basins and percolate into the groundwater aquifer for storage. The Los Angeles Department of Water and Power will later pump the water from wells, and after additional testing and treatment, the water will enter pipes and be delivered to taps.