SALEM, Ore. (AP) — City leaders in Lake Oswego and Tigard in Oregon and Anacortes in Washington are among the communities asking residents to reduce their water use during a chlorine shortage. Oregon Public Broadcasting reports the chemical used in small amounts by water treatment facilities to prevent harmful bacteria growth in drinking water supply. State officials say they have a plan to help water districts across Oregon get the chlorine they need if their stockpiles run low and there’s no threat to the water the public depends on. The shortage occurred after a power outage earlier this month at the Westlake chemical facility in Longview, Washington, the main provider of chlorine for Oregon.