SJRA Drinking Water Quality August 31 & September 1, 2011 Presented By: Mark Smith, PE, SJRA GRP Administrator Stan Williams, PE, HDR Project Manager

1. Drinking Water Quality
August 31 & September 1, 2011
Presented By:
Mark Smith, PE, SJRA GRP Administrator
Stan Williams, PE, HDR Project Manager

2. Agenda
 Water Quality – Regulations and Goals
 Three Steps to Treatment Process
Selection
 Post Treatment – Quality at the Tap
 Selected Treatment Processes
 Next Steps
 Discussion – Q&A

3. Perspectives on Drinking Water Quality
 Regulators define Drinking Water Quality by:
• Numeric Standards
• Treatment Techniques
• Compliance with Rule & Regulations
• Monitoring & Reporting
 For Quality Definition – First Look to the
Regulations

4. Evolution of the Safe Drinking Water Act
 1986 Safe Drinking Water Act (Update)
 Cryptosporidium Outbreak in 1993 Resulted
in:
• New perspective on surface water treatment
• Comprehensive overhaul of industry’s approach
• Unprecedented plan for new regulations
• Opportunities for innovation in treatment
technology

5. Drinking Water Quality
 Additional contaminants regulated
 Existing technologies enhanced
 New treatment technologies developed
 New Federal Regulations
• ESWTR, D/DBP, D/DBP2, LTESWTR,
LT2ESWTR, FBRR, and many more
High Quality Water 20 years ago would
not meet today’s standards

6. Project Quality Standards Consider The
Regulations AND the Consumer
 Project Standards go beyond the regs
• Alkalinity
• Hardness
• Aggressiveness (corrosiveness)
• Odor
• Taste
These Constituents Affect
Water Quality AT THE TAP

7. Project Quality Standards Consider The
Regulations AND the Consumer
 Project Definition of Water Quality:
• Compliance with Regulations
• Aesthetics at the tap
Clarity
Taste & Odor
Color
• Healthy and Safe
• Compatible with existing groundwater sources
• Consistent Quality

8. Existing Source Waters
Groundwater Characteristics Lake Conroe Characteristics
 Alkalinity - High  Alkalinity - Low
 Hardness - Moderate  Hardness - Moderate/Low
 Iron & Manganese – Yes  Iron & Manganese - Yes
 Aggressive – Yes  Aggressive - Yes
 Turbidity - Low
 Organics - High
 Pathogens
 Taste & Odor

9. Three Step Process to Selecting
Treatment Processes
 Step 1 - Bench Scale Studies
 Step 2 - Pilot Plant Studies
 Step 3 - Finished Water Polishing

10. Structured Screening Process Establishes
Viability of Alternates
Possible ID Primary
Treatment Desktop Study Impacts
Strategy
Evaluate NO Mitigation YES
Impact Impacts?
Possible?
YES NO
Develop Mitigation Implement Testing &
NO Impacts
Manageable? Strategies Further Evaluation
YES NO
YES NO Will
YES Secondary NO All Impacts
Mitigation
Work? Impacts? Addressed?
YES
Abandon Strategy Implement Testing &
Further Evaluation

11. STEP 1 - Bench Scale Studies Selects
Processes for Further Evaluation
 Review Historical Water
Quality Data
 Conduct Bench Scale
Treatability Studies
 Screen Potential Broken Arrow Settled Turbidity
Processes 7
6
Verdigris River Raw
Lake Conroe Water
Water
 Select Processes for Step
Turb. = 10.6 NTU
5
Turbidity, NTU
Optimum Dose
4
2 - Pilot Testing 3
2
1
0
10 20 30 40 50 60
Aluminum Chlorohydrate Dosemg/L
Ferric Sulfate Dosage, (mg/l)

12. STEP 2 - Pilot Studies Test Processes
Under Real Life Conditions
 Construct Pilot Plant Kruger Ceramic
Membranes
GAC
 Lake
Conroe
Operate Pilot Plant Static
Mixer
 Select/Rank Criteria
Pall Microza
Membranes
Membrane
Feed Tank

Static
Influent From
Lake Conroe
Evaluate Processes against criteria
Mixer
GE ZeeWeed
1000
Discharge
Tank
Discharge
Membranes
 Select Process for Full Scale Development
MIEX
Contactor
Conventional
Plate Settler Filter
Filter Feed
Tank
BAF
Ozone
Feed BAF
Contactor
Tank
Bypass
Stream
From From Membrane From From Cleaning From From From BAF
From Plate From From BAF Feed From BAF
Kruger Feed Feed Tank Conventional Neutralization Conventional BW Tank BW Tank
Settlers GAC Tank Overflow Backwash
Tank Overflow Overflow Feed Tank Tank Filter Backwash Overflow Overflow
Overflow
Gravity Discharge
Collector

13. Pilot Plant at Project Site

14. Pilot Plant at Project Site
Plate Settlers

15. Membrane
Filters Activated Carbon
Filters (GAC)
Pilot Plant at Project Site
Membrane Modules & GAC

16. Activated Carbon
Filters (GAC)

17. Process Process Description Criteria Rank Criteria
Train 1 Clarification + Conv. Filter 1 Community Impact
Train 1A Clarification + Conv. Filter + UV/H2O2 2 Water Quality Aesthetics
Train 1B Clarification + Conv. Filter + GAC 3 Relative Capital Cost
Train 2 PS + Ozone + BAF 4 O&M Requirements and Cost
Train 2A PS + Ozone/H2O2 + BAF 5 System Robustness
Train 3 PS + Polymeric Membranes Water Integration Compatibility/Blending
6
Train 3A PS + Polymeric Membranes + GAC Non-Proprietary Equipment
Train 3B PS + Polymeric Membranes + Organix
8 Safety and Environmental Site Impacts
Train 3C MIEX + Polymeric Membranes
Train 3D MIEX + Polymeric Membranes + GAC 9 Premium Pathogen Removal
Train 3E PS + Polymeric Membranes + UV/H2O2 10 System Simplicity
Train 4 Ceramic Membranes 11 Area Required and Site Constraints
Train 4A Ceramic Membranes + GAC
12 Regulatory Flexibility
Train 4B Ceramic Membranes + UV/H2O2 13 Ease and Cost of Expansion

18. Particle Size Relationships
Organic macromolecules
Colloids
Bacteria Viruses
Pollens Yeasts
100 mm 10 mm 1 mm 0.1 mm 0.01 mm 0. 1 nm
Red globule
hair visible to naked eye Smallest microorganisms Polio virus
Sand filter UF
Conventional MF Ultrafiltration
Filters Microfiltration
Membranes

19. Relative Sizes of Small Particles
Pencil Dot (40 µm)
Cryptosporidium
Oocysts (3 - 6 µm)
Giardia Cyst
(5 - 15 µm)
Average size opening
in a standard filter (60 µm)
Microfiltration (0.1 µm)

20. Conventional vs. Membrane Filtration
Granular / Mixed Media Membrane Media
• Irregular Pore Size Distribution • Controlled Pore Size Distribution
(50 -70 micron between grains) (0.1 micron)
• Probable Filtration • Absolute Filtration
20

21. STEP 3 – Finished Water Polishing
 Water Blending Chemistry Analyses
• Sample Water from Distribution System
• Sample Pipes from Distribution System
• Compare compatibility with proposed
treatment process
 Defines Required Water Chemistry
Adjustments
Finished Water Polishing Provides
Quality Water AT THE TAP

22. Understanding What’s In the Pipe Leads
to Compatible Water Chemistry
 Iron scales represent a
reservoir of metals,
particulates, and biomass.
 Chemistry changes in
distribution system
can release built-up
deposits

23. Finished Water Chemistry Must be
Compatible with Existing Infrastructure
Pipe Samples From Conroe
 Existing water is slightly
aggressive
 Minor corrosion scale
 No carbonate scale build-up
 Design water chemistry to
maintain existing corrosion
scale

24. Treatment Techniques for Compatibility
 Sodium Hydroxide:
Samples From The Woodlands
• Increase pH & alkalinity
 Calcium Hydroxide:
• Increase pH, alkalinity and
calcium
 Carbon Dioxide:
• Lower pH
All treatment chemicals are approved
by NSF for use in drinking water

25. Standard Indices Provide Goals for Post
Treatment
 The Langelier Saturation Index (LSI)
 Ryznar Stability Index (RSI)
 Calcium Carbonate Precipitation Potential
(CCPP)
 Larson Index (LI)

26. Post Treatment Provides Stable,
Compatible Water to Consumers
Desired Average Conditions
Parameter
Value Current Treated
LSI >0 -0.34 0.62
RSI <7 8.27 6.97
CCPP 4 – 10 -3.99 5.48
Larson Index < 0.8 0.54 0.49

27. Selected Treatment Processes
Membrane Post Treatment
Sedimentation
Filtration & Polishing
A B C 1 2 3 D E
CHEMICAL TREATMENT PHYSICAL TREATMENT
PROCESSES PROCESSES
A Permanganate – Iron & Manganese Sedimentation – Particulate and
1
Organics Removal
B Calcium Hydroxide – pH and Alkalinity
Membrane Filtration – Particulate
C Coagulant – TOC & Sediment Removal 2
Removal
D Sodium Hydroxide – pH & Alkalinity
Activated Carbon – Organic
3
E Chlorine - Disinfectant contaminants removal

28. Next Steps to Quality at the Tap
 Acquire and analyze water samples from
each receiving station – Refine post
treatment plans as necessary
 Identify treatment techniques currently used
at existing utilities
 Develop “Baseline Operations Report” at
existing systems
 Develop Guidelines to assist utilities to
prepare for surface water

29. Summary
 Federal & Texas Regulations dictate very
high drinking water quality
 Project Specific Standards drive
compatibility with existing groundwater
 Project focuses on “Quality at the Tap”
 Extensive testing of treatment techniques
and existing conditions provides real life
results – not textbook “rules of thumb”

30. SURFACE WATER TREATMENT PLANT
Questions / Discussion