1. WATER TECHNOLOGIES FOR RURAL TEXAS OFFICE OF RURAL COMMUNITY AFFAIRS Cryptosporidium: Technologies for Disinfection, Particulate Removal & By-Product Management Presented by Roger K. Noack, P.E.

2. WATER TECHNOLOGIES FOR RURAL TEXAS OFFICE OF RURAL COMMUNITY AFFAIRS Outline of Presentation History/BackgroundHistory/Background RegulationsRegulations Treatment Technologies AvailableTreatment Technologies Available Treatment Technologies LimitationsTreatment Technologies Limitations

3. WATER TECHNOLOGIES FOR RURAL TEXAS OFFICE OF RURAL COMMUNITY AFFAIRS History 1945 – Texas requires disinfection1945 – Texas requires disinfection 1974 – SDWA promulgated1974 – SDWA promulgated 1979 – THM Rule1979 – THM Rule 1986 – SDWA Amendments1986 – SDWA Amendments 1993 – Milwaukee Cryptosporidiosis outbreak1993 – Milwaukee Cryptosporidiosis outbreak 1996 – SDWA Amendments1996 – SDWA Amendments

4. WATER TECHNOLOGIES FOR RURAL TEXAS OFFICE OF RURAL COMMUNITY AFFAIRS Background Multiple Barrier ApproachMultiple Barrier Approach –Source Water –Treatment RemovalRemoval DisinfectionDisinfection –Distribution

5. WATER TECHNOLOGIES FOR RURAL TEXAS OFFICE OF RURAL COMMUNITY AFFAIRS Regulations Microbiological ContaminationMicrobiological Contamination –Giardia – 3-log removal/inactivation –Viruses – 4-log removal/inactivation –Cryptosporidium – 2-log removal –Turbidity – 0.3 NTU in 95% of samples

6. WATER TECHNOLOGIES FOR RURAL TEXAS OFFICE OF RURAL COMMUNITY AFFAIRS Regulations Disinfection and Disinfection By-ProductsDisinfection and Disinfection By-Products –CT (disinfectant Concentration x contact Time ) –Maximum Disinfectant Residual Level –Total Trihalomethanes –Haloacetic Acids –Chlorite –Bromate –Total Organic Carbon

7. WATER TECHNOLOGIES FOR RURAL TEXAS OFFICE OF RURAL COMMUNITY AFFAIRS Simultaneous Compliance Producing drinking water that meets all regulatory requirementsProducing drinking water that meets all regulatory requirements ALL RULES ARE EQUALALL RULES ARE EQUAL One rule cannot be undermined in favor of anotherOne rule cannot be undermined in favor of another Simultaneous compliance will be challengeSimultaneous compliance will be challenge

8. WATER TECHNOLOGIES FOR RURAL TEXAS OFFICE OF RURAL COMMUNITY AFFAIRS Disinfection ChlorineChlorine –Liquid –Tablet –Gas –On-site generation Chloramine (chlorine + ammonia)Chloramine (chlorine + ammonia) –Liquid –Gas

9. WATER TECHNOLOGIES FOR RURAL TEXAS OFFICE OF RURAL COMMUNITY AFFAIRS Disinfection OzoneOzone Chlorine dioxideChlorine dioxide Ultraviolet lightUltraviolet light

10. WATER TECHNOLOGIES FOR RURAL TEXAS OFFICE OF RURAL COMMUNITY AFFAIRS Limitations of Disinfectants ChlorineChlorine –Contact time –DBPs –Demand versus residual –Safety ChloraminesChloramines –Weak disinfectant –Potential regrowth

11. WATER TECHNOLOGIES FOR RURAL TEXAS OFFICE OF RURAL COMMUNITY AFFAIRS Limitations of Disinfectants OzoneOzone –Strong disinfectant –DBPs –No residual –Safety –Biodegradable organics affects water quality

12. WATER TECHNOLOGIES FOR RURAL TEXAS OFFICE OF RURAL COMMUNITY AFFAIRS Limitations of Disinfectants Chlorine DioxideChlorine Dioxide –Strong disinfectant –DBPs –No residual –Safety

13. WATER TECHNOLOGIES FOR RURAL TEXAS OFFICE OF RURAL COMMUNITY AFFAIRS Limitations of Disinfectants Ultraviolet lightUltraviolet light –Not a disinfectant –No residual –Special instrumentation –Special maintenance

14. WATER TECHNOLOGIES FOR RURAL TEXAS OFFICE OF RURAL COMMUNITY AFFAIRS Removal Technologies Conventional treatmentConventional treatment –Flocculation –Sedimentation –Filtration MonomediaMonomedia Dual mediaDual media Mixed mediaMixed media

15. WATER TECHNOLOGIES FOR RURAL TEXAS OFFICE OF RURAL COMMUNITY AFFAIRS Removal Technologies Direct filtrationDirect filtration Slow sand filtrationSlow sand filtration Diatomaceous earth filtrationDiatomaceous earth filtration Cartridge/Bag/Backwashable filtersCartridge/Bag/Backwashable filters

16. WATER TECHNOLOGIES FOR RURAL TEXAS OFFICE OF RURAL COMMUNITY AFFAIRS Removal Technologies MicrofiltrationMicrofiltration UltrafiltrationUltrafiltration NanofiltrationNanofiltration Reverse osmosisReverse osmosis

17. WATER TECHNOLOGIES FOR RURAL TEXAS OFFICE OF RURAL COMMUNITY AFFAIRS

18. WATER TECHNOLOGIES FOR RURAL TEXAS OFFICE OF RURAL COMMUNITY AFFAIRS Removal Tech. Limitations Conventional treatmentConventional treatment –Handle wide range of water quality –Expensive Direct filtrationDirect filtration –Low turbidity –Algae may be a problem

19. WATER TECHNOLOGIES FOR RURAL TEXAS OFFICE OF RURAL COMMUNITY AFFAIRS Removal Tech. Limitations Slow sandSlow sand –Low turbidity –Algae may be a problem Direct filtrationDirect filtration –Low turbidity –Low removal credits for Giardia/viruses –Algae may be a problem –Not allowed in Texas on surface water

20. WATER TECHNOLOGIES FOR RURAL TEXAS OFFICE OF RURAL COMMUNITY AFFAIRS Removal Tech. Limitations Diatomaceous earth filtrationDiatomaceous earth filtration –Good water quality required –Low bacteria and viruses removal Cartridge/Bag/BackwashableCartridge/Bag/Backwashable –Exceptional water quality required –Pretreatment required –Variable particulate removal

21. WATER TECHNOLOGIES FOR RURAL TEXAS OFFICE OF RURAL COMMUNITY AFFAIRS Removal Tech. Limitations MembranesMembranes –High pressure requires exceptional water quality –Stabilization of permeate required –Low pressure replaces conventional treatment –Cost is decreasing as usage increases

22. WATER TECHNOLOGIES FOR RURAL TEXAS OFFICE OF RURAL COMMUNITY AFFAIRS DBP Control Move the point of disinfectant applicationMove the point of disinfectant application Increase DBP precursor removalIncrease DBP precursor removal Change the disinfectant usedChange the disinfectant used –Primary –Secondary

23. WATER TECHNOLOGIES FOR RURAL TEXAS OFFICE OF RURAL COMMUNITY AFFAIRS DBP Control TemperatureTemperature pHpH Aggressive flushing programAggressive flushing program Corrosion leads to elevated disinfectant residualsCorrosion leads to elevated disinfectant residuals Supplemental (boost) disinfectant addition in the distribution systemSupplemental (boost) disinfectant addition in the distribution system

24. WATER TECHNOLOGIES FOR RURAL TEXAS OFFICE OF RURAL COMMUNITY AFFAIRS Questions & Answers