CLEAR LOGX Process ™

1. CLEARLOGXProcess™ Optimizing Total Organic Carbon Removal While Enhancing Membrane Filter Performance The Science of Water Made Simple

2. History • 67 Low pressure membrane plants in CO • 5 Years ago, only 2 dosed coagulant. • Dosed for color removal only. • Now 25 plants dose coagulant, mostly for DBP formation issues.

3. History: Membrane PerformanceWith Coagulant Dose • Improved membrane performance with regulated “low dose” • Higher acidic coagulant (ferric chloride) dramatically increased membrane fouling • More membrane plants require enhanced coagulation

4. 180 160 No Dosing Ferric Dosing 140 Alum Dosing 120 ACH Dosing 100 TMP (kPa) 80 60 Exact Operating Setpoints: - Flux - BW Interval 40 20 0 0 1 2 3 4 5 6 Days Membrane supplier coagulant fouling curve

5. Enhanced Coagulation • Higher coagulant dose • Opt for specialty coagulants • pH suppression w/ coagulant dose • Result: Higher TOC removal, higher membrane fouling

6. Types of Membrane Fouling • Organic. Clean with oxidant. • Inorganic. Clean with acid. • Third type of fouling: Charge fouling Address by correcting charge

7. Membrane Fouling Assumptions • Turbidity, particulates increase membrane fouling. False • Soluble organic content increases membrane fouling. False • Controlled coagulant feed can dramatically reduce fouling and increase membrane performance

8. Enhanced coagulation utilizing charge neutralization • Natural organic particles are almost always negatively charged. • Coagulant addition alters the particle surface charge and lessens the repulsive energy • Adsorption of a positively charged coagulant on the surface of the colloid can provide for: agglomeration of colloids, micro flocs, floc masses • Charge neutralization for conventional plants, alters the particle charges to optimize agglomeration, settling and filter runs.

9. TOC Removal

10. Streaming Current Charge Neutralization • SCM will control coagulant feed to optimize agglomeration/settling/filter runs • Enhanced coagulation, must turn off SCM

11. (-) (-) (-) (+) (-) (-) (+) (-) (-) (+) (+) (-) (+) (-) (-) (-) (-) (-) (-) (-) (-) (-) (+) (-) (-) (-) (-) (-) (-) (+) (-) (-) (-) (-) (-) (+) (-) (-) (-) (-) (-) (-) (-) (-) (+) (-) (-) (-) (+) (-) (-) (-) (+) (+) (-) (-) (-) (-) (-) (-) (-) (-) (-) (-) (-) Charge Neutralization

12. (+) (-) (+) (-) (-) (-) (-) (-) (-) (+) (-) (-) (-) (+) (-) (+) (+) (-) (-) (-) (-) (-) (-) (-) (-) (-) (-) (+) (-) (-) (-) (-) (-) (-) (-) (+) (-) (-) (-) (-) (-) (-) (+) (-) (-) (-) (-) (-) (-) (-) (-) (-) (-) (+) (-) (-) (-) (-) (+) (-) (-) (-) (+) (-) (+) (-) (-) (-) (-) (-) (-) (-) (-) (-) Approaching Net Zero Charge NeutralizationWith Membrane Filtration

13. (-) (-) (-) (+) (-) (-) (+) (+) (+) (-) (-) (-) (-) (-) (-) (-) (-) (-) (+) (+) (-) (-) (+) (-) (+) (-) (-) (-) (-) (-) (-) (-) (-) (+) (-) (+) (-) (-) (-) (-) (-) (-) (-) (-) (-) (+) (+) (-) (+) (-) (-) (-) (-) (-) (-) (-) (+) (-) (-) (-) (-) (+) (+) (+) Membrane Charge Neutralization

14. Manipulate Floc Particle Charge

15. Particle charge • pH can affect particle charge. Coagulants are weak acids • Temperature can affect particle charge. • Turbidity levels and particle size/shearing effects can alter charge.

16. Ft. Lupton Demonstration

19. Ft. Lupton, Colorado WTP • Failing DBP. Under Compliance Order • Needs: Expand Existing Memcor System, Increase Recovery and Comply with Stage 1, 2 DBP • Engineer 1 Recommended Uncontrolled Ferric + GAC System. Cost: $5,000,000 • Engineer 2 Recommended Uncontrolled Ferric + Clarification (LPS or Solids Contact Clarifier). Cost: $5,500,000

20. Direct feed mode

21. PLC M A C Acid/Base pH Monitor Chlorine Feed Chlorine Monitor Coagulant Feed Flow Meter Mixing Tank Membrane Filter Clear well CLEARLOGX Direct Feed Schematic

22. Clarifier feed mode

23. PLC P H M A C pH Monitor Acid Chlorine Feed Base Chlorine Monitor Coagulant Feed Flow Meter Clarifier Mixing Tank Membrane Filter Clear well CLEARLOGX Clarifier Feed Schematic

24. Clearlogx Process Demonstration Results • TOC Removal: Direct Feed: 50% Clarifier Feed: 79% • Flux: 50 – 70 gfd (minimal fouling) • Recommended Direct Feed (no clarification) • Low Mn FeCl3 coagulant • Clearlogx Process Selected

25. Direct feed mode 30 ppm Low Mn FeCl3, Uncontrolled 30 ppm Low Mn FeCl3, Controlled

26. Clarifier feed mode 30 ppm Low Mn FeCl3, Uncontrolled 30 ppm Low Mn FeCl3, Controlled

27. Temperature effects on charge

28. Temperature affects charge and membrane performance Maintenance Clean Ideal temperature Maintenance Clean

29. Recover from fouling event pH/charge change

30. Turbidity does not cause membrane foulingWrongly charged particles cause membrane fouling

31. Coagulant Selection

32. Ferric vs Aluminum Based Advantages • Higher TOC Removal • Lower Cost • More Acidic • Pretreatment to RO/Nano Disadvantages • Manganese, Ferrous Precipitation • Handling, Stains

33. Low Mn Ferric vs Conventional Ferric Advantages • No Manganese, Ferrous Precipitation Issues • No Dose Restrictions • Lower Contaminant Issues • Excellent Membrane Performance

34. Total DBP Control System

35. DBP Control Variables • Dose Coagulant Based On “Demand” Coagulant Dose Required To Remove TOC • Estimate Distribution System Detention Time • Control Chlorine Feed

36. Total Process Control for DBP Compliance

37. Questions?