San Diego communities are working together to diversify their water supply, with a plan to convert the wastewater that goes down drains and toilets, into purified drinking water. The Padre Dam Municipal Water District in Santee is leading the East County Advanced Water Purification Program. The district is working with Helix Water District, the city of El Cajon, and the County of San Diego to build a full-scale water purification facility on-site at Fanita Parkway.