Exclusion, Settling Prevention, Mechanical Removal, Oxidizing Biocides

2. Exclusion, Settling Prevention, Mechanical Removal, Oxidizing Biocides Chuck O’Neill Sr. Extension Specialist NY Sea Grant / Cornell University PREPARING FOR THE INVASION Zebra and Quagga Mussels in Utah Water Treatment Facilities 15 July 2008 Orem, Utah

3. Buried Intakes Dreissenid Control – Offshore Exclusion Eliminate most rapidly growing post-veligers before entering facility

4. Raised Fill Buried Intakes Dreissenid Control – Offshore Exclusion

5. Channel Rapid Filter Dreissenid Control – Offshore Exclusion

6. Dreissenid Control – Prevent Settling High-Velocity Flows Maintain intake/distribution flows: > 1.0 m/sec (vertical surfaces) > 1.5 m/sec (horizontal surfaces) • May not be possible due to: • Pipe size • Pump size • Conduit configuration • Rough walls (scale, welds, corrosion)

7. Prevents pediveliger attachmenton submerged steel structures Expanded metallic gridscan be applied to large submerged concrete surfaces Dreissenid Control – Prevent Settling Cathodic Protection

8. System must be “scrapable” Is there access? Can system go off-line? Dreissenid Control – Mechanical Removal • Useful in large conduits • Applicable where large musselsare present in large numbers • Expensive

9. Dreissenid Control – Mechanical Removal Pigging Most effective in systems: • With small diameter pipes • No large scale access • Which cannot easily be taken off-line Least effective when: • Conduits have very tight bends • Misalignment • Large infestations may block passage of pig

10. Dreissenid Control – Mechanical Removal • Hydro-Blasting • Abrasive Blasting • CO2 Pellet Blasting

11. Dreissenid Control – Oxidizing Biocides Off-Line Intermittent • Advantages • Minimizes chemical use/discharge • Minimizes environmental impacts • Minimal system retrofit • Disadvantages • Colonization = performance loss • Lost production during down time • Volume of mussels for disposal

12. Dreissenid Control – Oxidizing Biocides On-Line Intermittent • Advantages • No system down-time • Minimizes operational losses • Disadvantages • Additional chemical use may impact environment • High initial expense for retrofit • Lost production during retrofit

13. Dreissenid Control – Oxidizing Biocides On-Line Continuous • Advantages • No system down-time • Eliminates operational losses • Disadvantages • Additional chemical use may impact environment • High initial expense for retrofit • Lost production during retrofit

14. Dreissenid Control – Oxidizing Biocides • Chlorine • Chlorine dioxide • Ozone • Potassium permanganate • Hydrogen peroxide • Bromine • Chloramine

15. Dreissenid Control – Oxidizing Biocides • Chlorine • Chlorine dioxide • Ozone • Potassium permanganate • Hydrogen peroxide • Bromine • Chloramine

16. Dreissenid Control – Chlorine

17. Concentration May November Dreissenid Control – Chlorine Application End-of-Season

18. Concentration May November Dreissenid Control – Chlorine Application Periodic

19. Concentration May November Dreissenid Control – Chlorine Application Continuous

20. Concentration Day 1 Day 10 Day 20 Day 30 Day 40 November Dreissenid Control – Chlorine Application Intermittent

21. Concentration May November Dreissenid Control – Chlorine Application Semi-Continuous

22. Dreissenid Control – Sublethal Chlorination • > 0.1 mg/l : progressive reduction in physiologic activities • 0.5 mg/l : filtration reduced 88% • 0.5 mg/l : byssus production reduced 97% • Young mussels show higher percentage reductions at all levels than older mussels

23. Dreissenid Control – Drawbacks of Chlorination • Negative effects on non-target species • Negative effects on equipment • Too much = T&O issues • Damage to slow sand filters • Chlorination byproduct formation

24. Dreissenid Control – Ozonation • < 0.1 mg/l prevents byssus development • 0.18 mg/l 39 days 50% mortality • 0.32 mg/l 39 days 100% mortality

25. Dreissenid Control – Oxidant Injection