FILE - The Sept. 4, 2015 file photo shows the Carlsbad, Calif. desalination plant which borders Interstate 5 on one side and the Pacific Ocean on the other in Carlsbad, Calif. UN Warns of Rising Levels of Toxic Brine as Desalination Plants Meet Growing Water Needs. (AP Photo/Lenny Ignelzi, file)
FILE - The Sept. 4, 2015 file photo shows the Carlsbad, Calif. desalination plant which borders Interstate 5 on one side and the Pacific Ocean on the other in Carlsbad, Calif. UN Warns of Rising Levels of Toxic Brine as Desalination Plants Meet Growing Water Needs. (AP Photo/Lenny Ignelzi, file)