Narrator:        This is Science Today. An ultraviolet technology called UltraV, which is currently being tested as a disinfection system at wastewater treatment plants, may also someday help consumers in their backyard. Bassam Younis, a professor of fluid mechanics at the University of California, Davis says UltraV could also be used to disinfect swimming pools.

Younis:            It would work exactly as chlorine does - there is one difference between chlorine and UV light and that is, chlorine has longer lasting effect in a sense that when you put chlorine in the water and it stays in there, so there are benefits and there are disadvantages for this - the benefits is that the water is protected against re-infection.

Narrator:        The disadvantages are that chlorine may react with some organic material in the water and produce harmful by-products.

Younis:            I think at the last count, something like six hundred by-products of chlorine interaction with organic material and water had been identified.

Narrator:        For Science Today, I'm Larissa Branin.