Steve Reiber, Ph.D. • HDR Engineering • Seattle, WA

1. Water Treatment Past History/Future Challenges Legionella Steve Reiber, Ph.D. • HDR Engineering • Seattle, WA

2. Evolutionary Change in Water treatment – The History of a Developing Market Early water treatment engineers describe the first dirt molecule.

3. Take-Away Points • Despite predictions to the contrary, the cost of new technology (especially membranes) will not increase the cost of water treatment. • When quality is factored in, the cost of water treatment will actually decline. • Conventional sand filtration will be phased out in favor of low-pressure membranes. (This represents a 10 BGD market.)

4. Gate Houses and Chlorination Plant at Boonton Reservoir (Jersey City),circa 1908 Disinfection: The Most Important Treatment Step

5. DyNasand Filter Actiflow Deep Bed Mono-Media Evolution of Water Filtration Technology River Bed Filtration (Roman Times) Slow Sand Filtration (Germany 1820) Rapid sand filters are no longer the most cost-effective polishing step. Rapid Sand Filtration (Chicago 1900) Cellulosic Membranes (1980)

6. Market Drivers Numerous factors are influencing these changes. • New water supplies are inferior. • Fear of waterborne disease. • SDWA regulations • Expensive infrastructure replacement

7. Well-publicized “events” Bottled water sales increase dramatically The Water-Consuming Public is Aware (and Wary)

8. Waterborne Disease Outbreaks Cause Irreparable Damage to Public & to PWSs Source: HDR’s Handbook of Public Water Systems

9. Public Health Issues Pathogenic bacteria, viruses and protozoa in water and wastewater represent potential risks to public health. Bacteria (E.coli) Protozoa Viruses (Hepatitis, Polio) (Giardia) (Cryptosporidium)

10. Historical mortality from waterborne diseases exceeds the current mortality rates of all diseases combined. U.S. Leading Causes of Death (1990) Typhoid Fever Mortality in Chicago (1860-1950)

11. Classes of Microorganisms: The Microbial World Viruses: smallest (0.02-0.3 µm diameter); simplest: nucleic acid + protein coat (+ lipoprotein envelope) Bacteria: 0.5-2.0 µm diameter; prokaryotes; cellular; simple internal org.; binary fission. Protozoa: most >2 µm - 2 mm; eucaryotic; uni-cellular; non-photosynthetic; flexible cell memb.; no cell wall; wide range of sizes and shapes; hardy cysts and oocysts; flagellates (Giardia sp.), amoebae, ciliates, sporozoans (Cryptosporidium sp.) and microsporidia. C. parvum oocyst ~5 um

12. What is a low-pressure membrane? Membranes can remove anything that is smaller than the pores.

13. Giardia Cryptosporidium

14. A Short History of Membrane Technologies Membrane treatment is not new. Cellulosic membranes have been in use for four decades. What is new is that membrane systems are now affordable!

15. Membrane Treatment What is driving the technology? • Competitive costs • Complete microbial barrier • Improved organics removal • Small space requirements • Reduced solids • Automation

16. Teflon Polypropylene (PP) Polyvinylidenefluoride (PVDF) Polysulphone (PSf) Improved materials are the key to cost-effective performance. More recent polymeric materials are more robust than cellulosic materials. Chemical and Mechanical Resistance They foul more easily, but can be regularly and vigorously cleaned.

17. Growth in drinking water low-pressure systems is exponential. Combined Microfilter Ultrafilter Nanofiltration

18. Capital costs for membrane technology continues to drop. * *Per gal/d of Installed Capacity

19. Membrane Architecture is Evolving Encased systems trap solids, are difficult to backwash and cannot be used with high concentrations of coagulants or adsorbants, but offer high flux rates! Open systems are easier to backwash, but generally have lower flux rates!

20. Hollow Fiber Encased Membranes

21. Submerged Membranes Zenon’s ZeeWeed Process

22. TOC & DBPs (Coagulant/PAC/GAC) Taste & Odor (Aeration/PAC/GAC/ClO2) Soluble Fe & Mn (Oxidants) Arsenic (Ferric coagulants) Integration with Other Processes

23. Size Exclusion Device Cellulosic Systems Sorbant Coagulant Inflow Particle Removal vs. Dissolved Organics Removal Solids Contact Separation System Treated water Immersed membrane Evolution Residuals PVDF and Fluoropolymer systems

24. Membrane processes are not trouble free!

25. Cellulose acetate (CA) Hydrophilic Fouling Resistant Poly(m-phenylene isophtalamide) (Normex) Polyacrylonitrile (PAN) Hydrophobicity Polysulphone (PSf) Polyethersulphone (PES) Hydrophobic Fouling Susceptible Polyvinylidenefluoride (PVDF) Teflon Polycarbonate (PC) Polypropylene (PP)

26. Membrane Support Substrate

27. Fouling by organic material is the most serious threat to membrane operations. The dense NOM gel-like layer reduces capacity and fouls an unprotected membrane. Fouling at 20 hours; 79% flux reduction

28. Membranes do fail. However, failure is never catastrophic – less serious than microbial penetration of rapid sand filter beds. • Membranes fail incrementally – one fiber at a time. • Statistically, individual fiber breaks are insignificant to the overall microbial water quality.

29. Demand Supply Capacity Price What Will Not Change! Water Industry/Distribution System Issues Non-Commodity Pricing of Water!! • Urban-Industrial society depends on a safe and abundant supply of water. It is the most important public health function - bar none!!! • Water Wars are not imminent.

30. The American Water Industry is Not Being Privatized! Municipal advocacy supplants privatization efforts Merchant water will be limited to speculative markets.

31. Distribution Water Quality is Improving Almost 100% of national samples tested met health-based and aesthetic standards for drinking water Compliance Percent The number of tests failing water quality standards has fallen by 60% since 1992

32. 1990 1995 2000 2005 The Cost Efficiency of Public Water Purveyors is Increasing Cost as a % of Household Income Inflation-Adjusted Homeowner Costs $ / 1000 Gal. 1990 2000 • Public drinking water is a remarkable bargain • Efficiencies derive primarily from manpower and technology • It is still inexpensive despite more stringent regulations and dwindling supplies

33. Waterborne Disease Outbreaks are Decreasing. Distribution System Contribution is Increasing Source: Lee and Blackburn, 2004 1971 – 1974 1975 – 1978 1979 – 1982 1983 – 1986 1987 – 1990 1991 – 1994 1995 – 1998 1999 – 2000 2001 – 2002 • Most distribution failures are related to cross-connection and back siphonage. • Magnitude of outbreaks – 180 illnesses per event.

34. Disease and Distribution System • Evidence shows that current endemic levels of gastrointestinal diseases are associated with the consumption of tap water • The typical disease symptoms are generally mild, short term, and clear spontaneously • The organisms causingthese diseases arecultured in the distributionsystem (not the raw water)

35. Challenge – Many 20th century iron distribution mains are approaching the end of their service lives. Projected annual replacement needs for transmission lines and distribution mains. Source: EPA 2002) • Average post-WWII pipe service life ≈ 75 years. • 19th century cast iron pipe service life ≈ 120 years • Drinking water infrastructure spending to reach $6 billion per year by 2010.

36. 35% Substitute for other beverages 7% Taste 11% Other 35% Worried about tap water safety 12% Worried about tap water safety and substitute for other beverages Challenge - The Bottled Water Industry Continues to Grow Bottled Water Market U.S. Per Capita Consumption Why People Drink Bottled Water Fairly, or not, the continued success of bottled water creates the perception of a growing deficiency (“lack of purity”) in our public water system.