UV Technology as a Cost Effective Secondary Barrier for Cryptosporidium and Other Pathogens

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1 UV Technology as a Cost Effective Secondary Barrier for Cryptosporidium and Other Pathogens City of Columbus Division of Water Hap Cremean Water Plant UV Disinfection Project OAWWA 78 th Annual Conference Cincinnati, OH September 15 th, 2016

2 Acknowledgements City of Columbus, Division of Water Operation and Maintenance Staff Administrators HCWP Design Team Michael McWhirter & Kwasi Amoah, MWH, now part of Stantec James Collins & Stephane Jousset, ARCADIS DRWP Design Team Chris Schultz and Trent Branson, CDM Smith Paul Swaim, CH2M

3 Agenda 1 UV Treatment Process Selection 2 Facility Backgrounds 3 Location Selection 4 Design Flow 5 Technology Selection 6 Design UVT

4 1 UV Treatment Process Selection

5 Ongoing monitoring indicates presence of Cryptosporidium. HCWP SOURCE WATER (Oocysts/L) DETECTION ONLY GENOTYPING CURRENT PROJECTION FOR ROUND 2 SAMPLING Bin Bin 1 AVERAGE OF ALL DATA (SINCE DETECTIONS BEGAN) Bin Bin 1

6 Conventional treatment meets disinfection and removal requirements.

7 The City of Columbus is installing a secondary barrier at their plants. LT2ESWTR future? Backup for turbidity Safeguard to public health Secondary Barrier

8 Future Considerations for Cryptosporidium more to come? Monitoring Sampling Reporting

9 Alternative Methods used for Cryptosporidium Removal. Process $ Physical vs. Chemical Advanced Oxidation Processes (AOP) 10x Chemical Ozone 5-10x Chemical Reverse Osmosis (RO) 20-40x Physical UV Disinfection 1x Physical

10 UV Disinfection is an inactivation process. - DNA transformation - Germicidal range

11 UV Disinfection is effective against an array of pathogenic organisms. Cryptosporidium and Giardia Bacteria (Legionella, Escherichia coli, etc.) Viruses (Influenza, Hepatitis B Virus, Adenovirus, etc.) Mold Spores (Manure Fungi, etc.) Algae (Green Algae, Protozoa, etc.) Source: Water Research Center Drinking Water Treatment with UV Irradiation

12 Official OEPA credit can be achieved with UV Disinfection. OAC Microbial toolbox options for meeting Cryptosporidium treatment requirements.

13 2 Facility Backgrounds

14 Columbus has three drinking water plants.

15 There are two ongoing UV Disinfection projects in Columbus. Both Dublin Road and Hap Cremean Parallel Pre-Design and UV Equipment Pre-Selection Currently in Detailed Design

16 MWH is designing HCWP UV Disinfection.

17 Hap Cremean is a conventional surface water treatment plant and so much more!

18 2 Location Selection

19 Three potential locations were evaluated for UV. Location Combined Filter Effluent (New Building) Individual Filter Effluent (Filter Galleries) Downstream of the Clearwell Evaluated? Unfiltered Application Groundwater Application* Uncovered Reservoir Application* *Not Applicable at HCWP

20 Each location was evaluated based on four parameters.

21 Hap Cremean installing UV in the filter gallery. Dublin Road constructing a new UV facility.

22 3 Design Flow

23 The UVDGM flow requirements through filter galleries and other locations. Location Flow Requirement Combined Filter Effluent (New Building) Individual Filter Effluent (Filter Galleries) Downstream of the Clearwell Combined rated capacity of all duty filters Rated design flow for individual filter Rated capacity of the HSP station

24 The potential future flow rate was used for design. Current Filter Rating 3.2 gpm/sf (6.5 MGD per filter) Maintain Flexibility for Half Plant Operation Up to 70 MGD 11 filters available with 1 in backwash (6.4 MGD) 125 MGD During Construction 5.4 MGD (23 filters online) 6.3 MGD (20 filter online) Future Filter Rating 4 gpm/sf (8.1 MGD per filter) Possible under a range of conditions

25 4 Technology Selection

26 Medium pressure (MP) and low pressure high output (LPHO) technologies were evaluated. Power Output Number of Lamps Lamp Life MP Labor Requirements LPHO

27 Both technologies were allowed to bid at HCWP. Parameter MP LPHO Demonstrated UV Technology O&M Requirements Headloss Implications Mercurial Content Potential Auxiliary Benefits Operational Flexibility Cost Evaluation Environmental Considerations

28 5 Design UVT

29 What is UVT? - DEMONSTRATION

30 Historical data recommended a design UVT of 90.0 %/cm. UVT (%) % % % 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Cumulative Frequency

31 Data was collected through preliminary design to confirm design UVT.

32 Ozone has given a %/cm boost in UVT. Indiviudal Filter Effluent Online UVT (%) Online Analyzer Data Grab Sample Data Ozone off line

33 There are many reasons why UV is a great choice for PWSs. Protects public health Inexpensive Easy to operate and maintain Easy method to meet additional disinfection requirements.

34 Questions? Contacts: C.R. Weaver: (614) or Sarah E. Hayes: (614) or