… The Groundwater Replenishment System facility in Orange County, California, houses the pipes, filters and pumps to move up to 130m gallons each day – enough for 1 million people – processing it from dark to clear. The facility, which opened in 2008, is part of broader moves to help conserve water. … The idea is to take the water from the sanitation district next door and to push it through a three-step process – microfiltration, reverse osmosis and ultraviolet light purification – to make clean water. The facility provides 45% of central Orange County’s water and helps manage storm water inflows and reduce reliance on imported water. … In general, once sewage has been treated, the water is returned to our rivers, but extreme droughts and climate breakdown are pushing cities to consider using recycled sewage for drinking water. It is already done in Israel, Singapore and Kuwait, but Orange County has been a US pioneer in this area, hoping to reduce dependence on water piped from faraway rivers or pumped from shrinking aquifers under the ground.