1. EPCOR Water Services Inc.
Testing the waters: Setting up a pilot plant for Cryptosporidium removal experiments using Saccharomyces cerevisiae
Rasha Maal-Bared, Wendell James, Sadra Heidary-Monfared, Darlyce Simpson, Stephen Craik
EPCOR Water Services Inc.

2. Rossdale and E. L. Smith WTPs. They both are situated at the NSR banks
Rossdale and E.L.Smith WTPs. They both are situated at the NSR banks. EPCOR has achieved ENVIROVISTA Champion status which means we are committed to proactively protect the environment.
The practice of operating the Edmonton water treatment plants (WTPs) in direct filtration (DF) mode has been adopted during fall and winter as a means of reducing coagulant requirements and the associated mass of solid residuals discharged back to the North Saskatchewan River (NSR).
EPCOR Water Services Inc. (EWSI) operates two water treatment plants in Edmonton
During fall and winter both plants operate in direct filtration (DF) mode
During DF operation, plant capacity decreases

3. Rossdale and E. L. Smith WTPs. They both are situated at the NSR banks
Rossdale and E.L.Smith WTPs. They both are situated at the NSR banks. EPCOR has achieved ENVIROVISTA Champion status which means we are committed to proactively protect the environment.
The practice of operating the Edmonton water treatment plants (WTPs) in direct filtration (DF) mode has been adopted during fall and winter as a means of reducing coagulant requirements and the associated mass of solid residuals discharged back to the North Saskatchewan River (NSR).
EPCOR Water Services Inc. (EWSI) operates two water treatment plants in Edmonton
During fall and winter both plants operate in direct filtration (DF) mode
During DF operation, plant capacity decreases

4. Rossdale and E. L. Smith WTPs. They both are situated at the NSR banks
Rossdale and E.L.Smith WTPs. They both are situated at the NSR banks. EPCOR has achieved ENVIROVISTA Champion status which means we are committed to proactively protect the environment.
The practice of operating the Edmonton water treatment plants (WTPs) in direct filtration (DF) mode has been adopted during fall and winter as a means of reducing coagulant requirements and the associated mass of solid residuals discharged back to the North Saskatchewan River (NSR).
EPCOR Water Services Inc. (EWSI) operates two water treatment plants in Edmonton
During fall and winter both plants operate in direct filtration (DF) mode
During DF operation, plant capacity decreases

5. Water Treatment Process in Edmonton
Epcor currently operates two drinking water treatment facilities
Conventional filtration used throughout most of year
Processes used include: coagulation and flocculation, sedimentation, granular filtration and disinfection
Direct filtration used during months where turbidity and color are low
Processes used include: sedimentation, granular filtration and disinfection
Before conversion to DF in late summer/fall:
Evaluate raw water conditions (turbidity, colour)
Test for raw water Crypto
Convert to DF if less and 30 oocysts/100 L and other raw water parameters OK
During DF Operation in Fall/Winter
Meet all turbidity and particle count criteria (<0.08 NTU, < 45 p/mL) on individual filters
Monitor Crypto in raw and treated water bi-weekly during DF operation
Increase monitoring to weekly if Crypto detected in treated water
Continue to operate only if DF
Raw Water Conc. < 30 oocysts/100 L
Treat Water Conc. < 10 oocysts/1000 L

6. During DF Operation in Fall/Winter
Direct Filtration Mode (DF)
Epcor currently operates two drinking water treatment facilities
Conventional filtration used throughout most of year
Processes used include: coagulation and flocculation, sedimentation, granular filtration and disinfection
Direct filtration used during months where turbidity and color are low
Processes used include: sedimentation, granular filtration and disinfection
Before conversion to DF in late summer/fall:
Evaluate raw water conditions (turbidity, colour)
Test for raw water Crypto
Convert to DF if less and 30 oocysts/100 L and other raw water parameters OK
During DF Operation in Fall/Winter
Meet all turbidity and particle count criteria (<0.08 NTU, < 45 p/mL) on individual filters
Monitor Crypto in raw and treated water bi-weekly during DF operation
Increase monitoring to weekly if Crypto detected in treated water
Continue to operate only if DF
Raw Water Conc. < 30 oocysts/100 L
Treat Water Conc. < 10 oocysts/1000 L

7. Regulatory requirement
Alberta Environment and Sustainable Resource Development (AESRD) in DF
Filtration  physical log removals
Drinking water filtration can be divided into three phases: (1) filter ripening: attachment of particles to filter grains increases as particles are deposited; filter grains act as particle collectors; (2) effective filtration: particle-filter grain attachment is high enough to remove many of the influent particles from the effluent; (3) effluent breakthrough: as filter pores become clogged with particles, the particles begin to appear in the effluent, which becomes increasingly turbid.
UV disinfection: 5.5 log reduction

8. Cryptosporidium detections in DF
Date
Oocysts/1000 L
Nov 21, 2011 1
Sept 10, 2012 2
Sept 12, 2012
Sept 14, 2012
Sept 17, 2012
Sept 18, 2012
Nov 5, 2012
In 2013, 5 positive hits at Rossdale, and one at ELS.

9. Alberta Environment and Sustainable Resource Development (AESRD) in DF
Approval to Operate
Alberta Environment and Sustainable Resource Development (AESRD) in DF
Required  physical log reductions
Achieved  ≈2 log reductions
Drinking water filtration can be divided into three phases: (1) filter ripening: attachment of particles to filter grains increases as particles are deposited; filter grains act as particle collectors; (2) effective filtration: particle-filter grain attachment is high enough to remove many of the influent particles from the effluent; (3) effluent breakthrough: as filter pores become clogged with particles, the particles begin to appear in the effluent, which becomes increasingly turbid.
UV disinfection: 5.5 log reduction

10. Main Objective
Understand what variables impact filtration efficiency when operating in DF mode
Drinking water filtration can be divided into three phases: (1) filter ripening: attachment of particles to filter grains increases as particles are deposited; filter grains act as particle collectors; (2) effective filtration: particle-filter grain attachment is high enough to remove many of the influent particles from the effluent; (3) effluent breakthrough: as filter pores become clogged with particles, the particles begin to appear in the effluent, which becomes increasingly turbid.
UV disinfection: 5.5 log reduction
Increase in positive detections of Cryptosporidium in filtered water at very low levels
Correlated with higher source water concentrations
UV disinfection in place at all times
Evidence of reduced filtration efficiency, even though within EPCOR turbidity and particle count limits

11. Laboratory surrogate testing
To Crypto or not Crypto
Laboratory surrogate testing
Pilot plant surrogate testing
Cryptosporidium pilot plant runs
Pilot plant used to test log reduction

12. Cryptosporidium parvum Polystyrene microspheres
Seeding Options
Cryptosporidium parvum
Polystyrene microspheres
Saccharomyces cerevisiae
Endospores
Sulphite reducing clostridia
Bacillus subtilis
Other (algae, coliforms)
Crypto (Viable versus not viable)
B. subtilis: B. subtilis is often considered as the gram positive E. coli. Produces endospore that can remain viable for decades. Aerobic.
SRC: An aerobic, gram positive endospore formers.
Other (algae, coliforms)

13. Scientific considerations
Surrogate Selection
Scientific considerations
Size and shape
Surface properties (zeta potential)
Practical considerations
Risk
Cost Effectiveness
Potential for full scale testing
Contamination potential (Environmental and public health)

14. Surrogate Selection

15. Surrogate Selection - Options
Cryptosporidium parvum
Polystyrene microspheres
Saccharomyces cerevisiae
Endospores
Sulphite reducing clostridia
Bacillus subtilis
Other (algae, coliforms)
Crypto (Viable versus not viable)
B. subtilis: B. subtilis is often considered as the gram positive E. coli. Produces endospore that can remain viable for decades. Aerobic.
SRC: An aerobic, gram positive endospore formers.
Other (algae, coliforms)

16. Cryptosporidium surrogate selection
Laboratory surrogate testing
Pilot plant surrogate testing
Cryptosporidium pilot plant runs
Pilot plant used to test log reduction

17. Saccharomyces cerevisiae
Baker’s yeast
Single-celled or pseudomycelia
Round to ovoid
Diameter 5-10 μm
Safe model organism
Reproduce by lateral budding.
Taxonomy being scrutinized (18 species of Saccharomyces)

18. Compare and contrast Reproduce by lateral budding.
Taxonomy being scrutinized (18 species of Saccharomyces)

19. Saccharomyces cerevisiae Reconstituted with PBS
Procedure
Saccharomyces cerevisiae
Reconstituted with PBS
35⁰C for 1 hr
Baker’s yeast Type II Sigma Scientific
Added to reservoir water to desired concentration
Stored overnight in fridge
Stained with DAPI

20. Baker’s yeast Type II Sigma Scientific
Added to reservoir water to desired concentration
Stored overnight in fridge

21. Laboratory testing – zeta potential (mV)
(Seaman et al., 2015)

22. Practical considerations
Dosing
Concentration (approx. 106 cells/L)
Duration
Run time (68 minutes)
Sample collection method
Variables to monitor
Cost
Column tracer study using salt
Column tracer study
Effluent concentration increases at 15 minutes
Plateau between 20 and 40 minutes
Completely through column at 1 h 5 min.

23. Microsphere run cost Fluoresbrite® YG Carboxylate Microspheres 4.5µm
Total cost per bottle GLYCOPROTEIN modified microspheres ($/ 2.5 x 109 microspheres)
1,351.25
Total cost per bottle GLYCOPOLYMER modified microspheres ($/ 2.5 x 109 microspheres)
387.00
4.50µm particles packaged as 2.5% aqueous suspension x 10^8 particles/ml Diameter Coefficient of Variation (CV) = 7% Excitation max. = 441nm Emission max. = 486nm
Microspheres; 5 mL bottle with $/4.99 x 10^8 particles/ml

24. Cryptosporidium surrogate selection
Laboratory surrogate testing
Pilot plant surrogate testing
Glycopolymer-coated microsphere runs
Pilot plant used to test log reduction

25. Pilot plant surrogate testing
ELS Clarifier effluent
Splitter Box Train 1
Splitter Box Train 2
Dual media columns
Dual media columns
PC and Turbidity
PC and Turbidity
Splitter Box Trains (polymers added)
Dual media columns
(Anthracite and sand)  PC and Turb meters on column efflunet
Filled columns with sand and anthracite layers to match WTP filters
Used a common splitter box for all trains
Monitored the static pressure and flow
Drain
Drain

26. Insert Pics of pilot plant and sampling apparatus

27. Pilot plant surrogate testing
760 mm (500 sand, 260 anthracite)

28. Results – Initial runs Run # Batch seed (cells/L)
Influent concentration yeast (cells/L)
Run time (min)
Estimated log removals 1
1 x 109
8.2 x 106 12
1.34 2
1.2 x 107 31
1.28 3
1 x 107
4.7 x 105 75
1.50 4
9.1 x 105 70
1.82

29. Lessons learned
Influent counts
Flow rate adjustment
Water temperature and filter ripening
Particle counts and turbidity – using control columns
Grab or continuous sampling

30. Results – Modified microsphere run
Flow rate (L/min)
Treatment Mode
Run time (min)
Estimated log removals 1
3 L/min DF 75
1.46 2
2 L/min
115
1.73
Batch for all experiments 1.5 x 108
Dosing for all experiments 1.5 x 108 microspheres/L

31. Results – Modified microsphere run
Flow rate (L/min)
Treatment Mode
Run time (min)
Estimated log removals 1
3 L/min DF 75
1.46 2
2 L/min
115
1.73 3
Conventional 90
2.06 4
137
3.16
Batch for all experiments 1.5 x 108
Dosing for all experiments 1.5 x 108 microspheres/L

32. Acknowledgements EPCOR Lab Staff University of Alberta Collaborators
Ian van Beers, Sharon Lu, Debra Long
University of Alberta Collaborators
Yang Liu, Ravin Narain, Jeff Seaman (Environmental Engineering)
Al Shostak (Department of Biology)
City of Ottawa
Ian Douglas, Andy Campbell

33. Thank you for your time
Any Questions?