1. UV Disinfection for Unfiltered Surface Water Regulatory Compliance Kevin Castro, PE | GHD Image placeholder

2. UV Disinfection for Unfiltered Surface Water Regulatory Compliance Kevin Castro, PE | GHD

3. 2013 NYC Watershed/Tifft Science & Technical Symposium Presentation outline Background Regulatory Requirements Water Quality Basis of Design Procurement/Construction Benefits/Results Lessons Learned Questions Image place holder

4. 2013 NYC Watershed/Tifft Science & Technical Symposium Village of Skaneateles, New York Village demands –0.6 mgd average daily demand –1.2 mgd maximum daily demand –2.0 mgd pump capacity Served off City of Syracuse Skaneateles Lake supply FAD since 1991 3 log giardia inactivation through chlorination (using City of Syracuse chlorination) Population served ± 3,000

5. 2013 NYC Watershed/Tifft Science & Technical Symposium Skaneateles/Syracuse water supply system

6. 2013 NYC Watershed/Tifft Science & Technical Symposium Regulatory requirements SWTR –1991 FAD –3 log giardia inactivation through chlorination –4 log virus inactivation through chlorination –Contact tank and contact transmission main constructed 1995 LT2ESWTR –2 or 3 log cryptosporidium inactivation –Two barriers: UV/Cl2

7. 2013 NYC Watershed/Tifft Science & Technical Symposium Water quality Turbidity –Average = 0.8 NTU –Range = 0.5 to 10 NTU –Syracuse intake shutdowns control turbidity UVT –Average = 97% –Minimum value = 92% –ICR = 96 to 98% –Limited historical data –Design Range = 90 to 98% Cryptosporidium –1 oocyst detected since 1986 2 log cryptospordium inactivation required Fouling Potential - Low Image place holder

8. 2013 NYC Watershed/Tifft Science & Technical Symposium Basis of design 2 log cryptospuridium inactivation = 5.8 mJ/cm2 3 log giardia inactivation = 11 mJ/cm2 Designed for 3 log giardia inactivation UVT – 90% minimum -95% average Turbidity < 10 NTU Lamp Technology – Medium Pressure or LPHO Two 100% redundant UV reactors

9. 2013 NYC Watershed/Tifft Science & Technical Symposium Basis of design (cont’d) Max flow = 2 mgd Ave flow = 1 mgd Min flow = 0.5 mgd Reduce giardia chlorine contact time requirements Max headloss – 7 inches Improved monitoring (UVT, Turbidity, Cl2)

10. 2013 NYC Watershed/Tifft Science & Technical Symposium Procurement Preselection vs. pre-purchase Preselection approach chosen to give contractor ultimate responsibility for system performance. Life cycle cost bid -Equipment costs -Lamp/ballast costs -Power costs

11. 2013 NYC Watershed/Tifft Science & Technical Symposium Procurement Procurement results Trojan awarded selection Equipment PV – Lamp Replacement PV – Ballast Replacement PV - Annual Power Total Life Cycle Cost Svern Trent$121,594$5,173$14,200$9,884$150,851 Trojan$117,000$21,460$5,976$8,045$152,481 Calgon$141,860$9,079$5,970$9,986$166,895

12. 2013 NYC Watershed/Tifft Science & Technical Symposium Construction Space available with BPS Pump replacement * VFDs provided * -Reduce pump flow to 1 mgd (90% speed) -Reduce pump energy cost by $4,000/year -Reduce pump starts to < 4/day -Eliminate cavitation of pumps on low lake level SCADA for monitoring/control/reporting *Provided through ARRA grant Image place holder

13. 2013 NYC Watershed/Tifft Science & Technical Symposium Construction UV Disinfection UV Controls

14. 2013 NYC Watershed/Tifft Science & Technical Symposium Construction Pumps Image place holder SCADA

15. 2013 NYC Watershed/Tifft Science & Technical Symposium Construction Turbidity/Chlorine/UVT Monitoring Image place holder Chlorine Booster System & Monitoring

16. 2013 NYC Watershed/Tifft Science & Technical Symposium Results/ benefits 2 log cryptosporidium inactivation – compliance 3 log giardia inactivation through UV/Cl2 4 log virus inactivation through Cl2 Use transmission main and contact tank for improved fire protection (currently under development) Reduced pump starts to < 4/day Reduced energy/cost for pumping Improved monitoring/reporting of CT, turbidity, Cl2 residual < 0.1% off-spec water since March 2012

17. 2013 NYC Watershed/Tifft Science & Technical Symposium Lessons learned Validation layout ≠ Approved layout Alarm management during maintenance -Nuisance alarms during lamp and UVT transmitter maintenance Preselection was effective procurement approach Avoid pre-preselection design layouts ($$) Define distances for power/instrumentation cabling LT2ESWTR allows off-spec water

18. 2013 NYC Watershed/Tifft Science & Technical Symposium Questions? Please contact Kevin Castro at kevin.castro@ghd.com

19. 2013 NYC Watershed/Tifft Science & Technical Symposium www.ghd.com