Nontoxic Sparker Control of Zebra Mussels

Zebra mussels are a nonindigenous aquatic nuisance that now extends from the Great Lakes to the mouth of the Mississippi River. Zebra mussels clog intake pipes, screens, cooling systems, and so on, and are a serious problem. The Nonindigenous Aquatic Nuisance Prevention and Control Act and Amendments mandate control of zebra mussel infestations. Chlorine effectively controls zebra mussels but produces disinfectant by-products, some of which are carcinogenic. Many alternative technologies have been attempted, but a viable means of effectively managing zebra mussels has not been demonstrated.Sparker technology is a potential nontoxic control method. Sparkers emit pressure pulses that can prevent the growth of new zebra mussels and clear away adult zebra mussels. However, the only commercial sparker is not widely used because of effectiveness questions, the need to replace electrodes frequently, and a high capital cost. Phoenix Science & Technology, Inc., has developed innovative sparker sources with high efficiency, proprietary electrodes, and acoustic reflectors. The objective of this Phase II project is to develop a new low-cost, long-lifetime sparker system with proven zebra mussel control capabilities. The feasibility of sparker control was demonstrated in Phase II. Field tests at two water intake pipes determined the pressure levels needed to control zebra mussels, and for the first time determined the control range of a sparker. In laboratory experiments, Phoenix Science & Technology, Inc., demonstrated how to increase electrode lifetime by a factor of four and designed a conceptual low-cost sparker.