Simultaneous Solutions for Aesthetics and Other Water Quality ...

1. Simultaneous Solutions for Aesthetics and Other Water Quality Problems Stephen Booth, PhD Craig Thompson, PE

3. USEPA SMCLs - Aesthetics

4. USEPA SMCLs � Aesthetics (Cont�d)

5. Groundwater Aesthetics Iron-reducing bacteria and soluble iron Sulfur-reducing bacteria and sulfides High mineral content Salt water intrusion Contamination

6. Surface Water Issues Planktonic and benthic algae Proliferation of algae in reservoirs Agricultural runoff Industrial discharges Wastewater plant discharges

7. Surface Water Odor Qualities Earthy/Musty Grassy/Green Vegetation Decaying/Marshy Fishy Septic Medical/Chemical MTBE (chemical) Woody/Hay Soapy

8. After Treatment� Distribution system issues Plumbing and storage Distribution system issues Water age Chemical changes Chlorine residual depletion DBP formation Plumbing and storage Pipes (corrosion) Reservoirs (open or closed) Plumbing materials (and water heaters) Distribution system issues Water age Chemical changes Chlorine residual depletion DBP formation Plumbing and storage Pipes (corrosion) Reservoirs (open or closed) Plumbing materials (and water heaters)

9. Geosmin (t-1,10-dimethyl-t,9-decalol) Geo (earth) + osme = odor Customer complaints common > 10 ng/L Odor threshold at 45�C ~5 ng/L

10. 2-MIB (2-Methylisoborneol) Odor descriptors: musty, peaty, earthy, damp soil Sensitivity highly variable

11. Treatment Techniques Established: Oxidation Adsorption Emerging: Advanced Oxidation Biodegradation Alternate Adsorbents

12. Evaluating Alternatives Oxidation / Advanced Oxidation Ozone Chlorine dioxide Potassium permanganate UV + Peroxide Adsorption GAC PAC

13. Taste versus Safety Ratings Source controls are not sufficient Public perception of safety Source controls are not sufficient Public perception of safety

14. Lake Bard Water Filtration Plant Calleguas Municipal Water District Source water is Lake Bard Seasonal algae problems results in T&O Ozone process Oxidizes T&O Improves micro-flocculation High downstream filtration rates (9 gpm/ft2) Overall improvement in water quality Achieve multiple objectives - T&O and� Disinfection DBP compliance Improved filtration performance Overall improvement in water quality Achieve multiple objectives - T&O and� Disinfection DBP compliance Improved filtration performance

15. Oxygenation System Schematic Ozone also improves source water quality! Unique process uses ozone off-gas Prevents anoxic hypolimnion Off-gas transferred to eductors located above the Lake Gas and oxygen-enriched water transferred to the lake hypolimnion Ozone also improves source water quality! Unique process uses ozone off-gas Prevents anoxic hypolimnion Off-gas transferred to eductors located above the Lake Gas and oxygen-enriched water transferred to the lake hypolimnion

16. Tower and Eduction System Ozone treats for T&O and also improves filtration efficiency Off-gas used to improve oxygenation of hypolimnion Ozone treats for T&O and also improves filtration efficiency Off-gas used to improve oxygenation of hypolimnion

17. Jamieson Canyon Water Treatment Plant City of Napa, CA Current plant expansion: 12 to 24 mgd North Bay Aqueduct Water Quality Episodes of elevated TOC and turbidity Terminal Reservoir subject to algae and T&O Open (sunlight) Nutrient input from bird population

18. Raw Water Quality

19. Ozone System Design Criteria

20. Jamieson Canyon WTP (Cont�d) Pre-Ozone for simultaneous benefits: T&O treatment Pre-oxidize without forming THMs and HAAs Oxidation of organics and color Lower coagulant dosage

21. Jamieson Canyon WTP (Cont�d) Pre-Ozone for simultaneous benefits: Disinfection benefit Ability to use settled water pipe as intermediate ozone contactor Removal of PPCPs

22. Conclusions Taste and odor quality important to consumers Expense of T&O treatment drives us to look for multiple benefits Opportunity for creativity