AWWA ACE91163

Control methods which have been researched in the past, and are being re-evaluated today fall into three categories: biological, physical/mechanical, and chemical. Chemical methods generally prove the most effective for short and long term control of the zebra mussel, although some facilities choose to utilize physical/mechanical means. Chlorine and chlorine derivatives, potassium permanganate, ozone, and various molluscides are all acceptable chemical methods for eliminating zebra mussels. Choosing a control method requires evaluation of several factors. Regulatory agencies have much to say regarding the use of chemicals in water treatment. Another factor in the evaluation of treatment options is the operating capacities of the existing water intake system. Specific applications of zebra mussel control methods undertaken are presented in four case studies: one that illustrates physical methods (vacuum removal of the mussels on the intake cribs and cleaning of raw water lines by pigging) and three that illustrate chemical methods (sodium hypochlorite, chlorine, and chlorine plus potassium permanganate).