Proactive control involves the use of various control strategies for preventative means. Perhaps the most effective proactive control method would be to draw water from a public water source or a groundwater well, but this may not be possible for some facilities. Other proactive control methods such as infiltration intakes or sandfilter intakes, which act by filtering out veligers and adults from the water supply, may eliminate the likelihood of zebra mussel infestation.
Some of these control methods are able to be used as reactive control methods as well, or in accompaniment with reactive control methods for better, more efficient results. A good example of this might be the use of chemical or thermal treatments as a reactive measure and then again, in repeated intervals, as a proactive and prevention treatment method. Final selection of the control method(s) to be implemented should be based on a variety of factors, including technical and economic feasibility and environmental impact. What is suitable for one site within a facility might be entirely impractical for another.
Figure A
An encrusted wall of a condenser cooling unit.
Figure B
Fouled trash and fish protection grate.
Figure C
Clogged intake screen.
In the three above examples of fouling, mussels could be effectively removed by using a physical method such as carbon dioxide pellet blasting or scraping. High-pressure water jet cleaning with pressure between 27,600 and 68,900 kPa would also be an efficient physical means of removal. But without a proactive or preventative means of treatment, the reactive approach of physical removal would again become necessary over time.
While a preventative chemical treatment or a thermal treatment might be a prudent choice as a proactive solution for Figure A, the fouling depicted in Figures B and C might require other proactive means of control such as the application of an antifouling coating. The fouling illustrated in the latter two figures might be best mitigated by modifying the system, which might include dual intakes (where one would be able to be shut down for inspection, removal, and treatment).
Management and Control Contents
Management and Control Options
Repellent Construction Materials
Antifouling, Foul Release, and Thermal Spray Coatings