The Knoxville (Tenn.) Utilities Board (KUB) has begun a test using the chemical chlorine dioxide in its water-purification process on a trial basis.
"Chlorine dioxide is a remarkably effective and safe way to purify drinking water for our customers," says Bill Elmore, KUB's chief operating officer. "This change will help us provide even better-tasting water while at the same time anticipating stricter drinking water standards by limiting the amount of chlorine we use."
During the water treatment process, water is disinfected twice: once as it enters the plant, and again before it enters the distribution system. During the test period, KUB will use chlorine dioxide in place of chlorine to disinfect drinking water at the beginning of the purification process. The utility will continue to add chlorine to the purified water just before it leaves the plant to help ensure the water maintains its quality until used by the customer. KUB plans to test the use of chlorine dioxide for six weeks, with plans to finalize a permanent switch by early next year.
"Chlorine is the most widely used disinfectant in the water industry," Elmore explains. "However, some customers are sensitive to the smell of chlorine. This change will help improve our customers' enjoyment of their water."
KUB recently tested a variety of treatment processes on its state-of-the-art pilot water plant, which allows KUB to test new processes under the exact same conditions as in the larger plant without releasing the finished water into its distribution system. "We are fortunate to have the pilot plant available to us," says Elmore. "Our tests there have shown that chlorine dioxide performs well in our treatment process, with the best combination of purity, cost and usability."