For years, the Anchorage Water & Wastewater Utility had used chlorine gas as the disinfectant at its water and wastewater treatment plants.In the late 1990s, the utility changed direction. “Our main concern was risk to the community,” says David Persinger, P.E., director of the AWWU treatment division. “In Alaska, everything comes by truck or barge. The chlorine cylinders were barged in.“Our port is just north of downtown Anchorage. So the 2,000-pound cylinders, usually 12 at a time, had to be transported on a truck through the downtown and some residential areas to get out to our main treatment plant. Then
