Advanced treatment of municipal wastewater could increase available water supplies in the U.S. by 27 percent, according to a recent report by the National Academy of Sciences. Of the 32 billion gallons of municipal wastewater discharged each day nationwide, about 12 billion gallons of effluent is emptied into an ocean or estuary, the report said. Existing treatment technologies would allow municipalities to reuse that water for a variety of purposes — including irrigation, industrial use and drinking water — while posing no increased risk of exposure to microbial or chemical contaminants than in some existing drinking water systems. As reported in the New York Times, an increasing number of U.S. communities are utilizing wastewater reuse technologies — including a pilot plant in San Diego that produces about 1 million gallons of clean drinking water daily — or are considering it. According to the National Academy report, increased stress on water supplies as a result of climate change and population growth will require many municipalities to consider alternative sources of water.