1. Disinfection of Water Treatment Systems Laura Jo Bertrand Josh Croll Joel

2. What is a Water Treatment System Is a form of cleansing wastes and other harmful microbes from water supplies. Reduces the risk of waterborne and foodborne diseases.

3. Traditional Disinfection Methods Initially functional methods, but many microbes have become resistant to some treatments. Traditional indicators for pathogens and bacteria are not as effective and reliable. The main form of treatment, free Cl, can be harmful to surface water animals and may react in the environment to form carcinogens and mutagens

4. OUTBREAK!!! Between 1978-86 111,228 waterborne cases of illness. 1986-88 24 states reported 50 outbreaks of illness, effecting 25,846 individuals. 1991-92 17,464, more recently in 1994 an outbreak infected an estimated 403, 000 people. As seen from the statistics that with time cases seem to be increasing even though technology should be improving.

5. Sensitivity to Disinfection Vegetative Bacteria > Viruses > Bacterial Spores = Acid-Fast Bacteria = Protozoan Cysts

6. Microbial Test Influences Sensitivity varies within species or groups Prior Exposure Injury Viable but non-culturable

7. Factors Influencing Effectiveness Aggregation (clumping) Dissolved organic matter Inorganic Matter Temperature Bioreactor type, mixing Attachment or colonization

8. Point-of-Use Water Treatment System (POU WTS) Drinking water treatment Disinfection using carbon block filter and UV light reactor. Removes/inactivates greater than 99% of bacterial pathogens, viruses, and protozoan.

9. Disinfection of Biofilms A biofilm is a microbial layer that forms on surfaces Traditionaly treated with Free Cl Dependent on type of surface biofilm is found. Free Cl used now causes specific environmental problems. Monochloramine is hoped to be a safer and more effective treatment.

10. Conclusion Efficiency may be site/system specific In depth site studies are rarely performed Indicators are useful but incomplete Recent studies are directed toward the use better indicators