UV light, light (wavelengths between 40 and 4,000) is a prospective zebra mussel control method. Chalker-Scott, et al. (1993) found that not only are zebra mussel veligers sensitive to UV-B radiation (2800-3200), but also adult zebra mussels, provided that the radiation is applied constantly. EPRI (1992) reported that veliger mortality was 42 percent after 1 hr, 85 percent after 2 hr and 100 percent after 4 hr exposure to UV-B radiation.
EPRI (1992) stated that large UV units are now available that can treat flow rates of up to 2.5 m3/sec. UV lamps can be installed in the intake bay or a pipe perpendicular to the flow or along sidewalls to control zebra mussels. Water with high suspended loads and high turbidity limit the depth at which light wavelengths can penetrate the water column, reducing the effectiveness of UV light. A possible impact, although no environmental impacts as predicted expected from the UV treatment is that nontarget species also may be killed. UV light is most applicable in medium-sized service water systems and other smaller raw water systems.