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.

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

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

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

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

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

Regulatory requirement Alberta Environment and Sustainable Resource Development (AESRD) in DF Filtration  2.5 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

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.

Alberta Environment and Sustainable Resource Development (AESRD) in DF Approval to Operate Alberta Environment and Sustainable Resource Development (AESRD) in DF Required  2.5 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

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

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

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)

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)

Surrogate Selection

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)

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

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)

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

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

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

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

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.

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. 4.99 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

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

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

Insert Pics of pilot plant and sampling apparatus

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

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

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

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

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

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

Thank you for your time Any Questions?