1. Desalination & Clean Water Technology Industry-Government Forum August 23, 2012 Roger Bailey Public Utilities Director

2. Policy Development • Water Supply Reliability • Local Supply Development • Legal Constraints • Natural Disasters • State and Federal Regulations • Water and Waste Water Treatment Processes • Affordability for Ratepayers

3. Water Supply: Seven-Year Average

4. Water Supply Reliability • Limited local supplies • Increasing cost of imported water • Pumping restrictions • Recurring drought conditions • Internal population growth • Natural disasters

5. State and Federal Regulations • Drinking Water Quality • Upgraded all three water treatment plants • Alvarado and Miramar – Ozone treatment • Otay – Chlorine Dioxide • National Pollutant Discharge Elimination System Permit • Modified Permit allows advanced primary treatment at Pt. Loma Waste Water Treatment Plant

6. State and Federal Regulations • Greenhouse Gas Emission Reduction • AB 32 requirements • Energy/water/waste water nexus • Need technologies to improve reliability, treatment while reducing energy consumption • Water Conservation Mandate • 20% by 2020 • “Low hanging fruit” is taken – support new ideas

7. Water and Waste Water Treatment • Upgraded all three water treatment plants • Alvarado and Miramar – Ozone treatment • Otay – Chlorine Dioxide • Modified Permit allows advanced primary treatment at Pt. Loma Waste Water Treatment Plant • Completed Recycled Water Study in July 2012 • Condition of Coastal Commission approval for 2010 NPDES permit

8. Water Purification Demonstration Project • Operate one MGD facility • San Vicente Reservoir study • Define regulatory requirements • Conduct energy & economic analysis • Public education & outreach Components Outcomes • Validate treatment process • Gain regulatory approval • Evaluate cost • Public acceptance

9. Recycled Water Study • Identify opportunities to increase recycling of wastewater for Indirect Potable Reuse (IPR)and Non-Potable Reuse (NPR) for a 2035 planning horizon • Determine the extent recycling can reduce wastewater flows to the Point Loma Wastewater Treatment Plant • Determine implementation costs

10. Recycled Water Study • Two Forms of IPR Evaluated: • Groundwater Recharge • Reservoir Augmentation • Findings: • Groundwater basin size and data insufficient to determine potential recharge projects. Revisit when more data is available

11. Recycled Water Study • Findings: • Two reservoirs deemed large enough to provide retention times within range required in draft groundwater recharge regulations • San Vicente Reservoir • Otay Reservoir

12. Recycled Water StudyPrioritized Next Steps • Finalize the Water Purification Demonstration Project (Dec 2012) • Conduct Facility Siting Studies • Evaluate cost sharing concepts • Prepare Financing Plan • Integrate into Point Loma Waiver Process • Confirm Otay Reservoir IPR Potential

13. Affordability for Ratepayers • Water and waste water service are fee based • Revenues for the system are derived from customers’ bills • The City has had success when State and Federal grant funds are available • Future enhancement to system must be financially beneficial for ratepayers

14. Questions

15. Back up slides to follow

16. San Diego Water Reuse Timeline • 1993 City & County Water Authority propose Water Repurification Project • 1994 Congress passes the Ocean Pollution Reduction Act, allowing the City to reapply for a waiver that is later granted • 1994-1998 Planning, regulatory reviews & conditional approval (DPH), preliminary design on project (20 TAF or 18 MGD) • Fall 1998 Water Repurification Project becomes an issue in several closely contested political campaigns • Spring 1999 Project cancelled by City Council

17. San Diego Water Reuse Timeline • 2002-2004 City enters into a settlement agreement with environmental groups committing to: • Evaluate improved ocean monitoring • Pilot test biological aerated filters • Conduct study on increased water reuse • 2004-2005 City undertakes Water Reuse Study • October 2007 City Council votes to proceed with the Demonstration Project  Water Purification Demonstration Project • November 2008 City Council approves temporary water rate increase to fund $11.8 million project • January 2009- Temporary water rates in effect August 2010

19. Membrane Filtration • Side-by-side microfiltration (MF) & ultrafiltration (UF) to test effectiveness prior to reverse osmosis • Pressurized hollow fiber membranes • MF nominal pore size: 0.10 microns • UF nominal pore size: 0.02 microns

20. Reverse Osmosis: Step Two • Same technology used by bottled water companies • Forces water under high pressure through sheets of plastic membrane • Demineralizes and purifies water

21. Ultraviolet Light/Advanced Oxidation Process (UV/AOP) • RO permeate combines and feeds UV/AOP • Hydrogen peroxide (30%) injected upstream of UV at 3 mg/l • UV system utilizes low pressure/high output lamps • Single reactor, 72 lamp configuration Ultraviolet (UV) plus H2O2 Disinfection

22. Testing & Monitoring Plan Objectives • Demonstrate proposed water purification technology will produce water quality that meets public health and reservoir augmentation criteria • Evaluate nutrient removal performance of the AWP Facility treatment train • Demonstrate integrity monitoring techniques and performance reliability measures • Monitor and collect operational and maintenance requirements of the AWP Facility equipment

23. Water Quality Results - Overview • Exceptional overall water quality, met all project treatment goals • Purified water met all drinking water standards • Equipment at each step in the treatment process is performing properly

24. San Vicente Limnology and Reservoir Detention Study • Dam to be raised 117 feet • Currently 90,000 acre-feet • 242,000 acre-feet after dam raise • Construction duration 2009-2013 • Augmentation would improve water quality

25. Information Visit: www.purewatersd.org Email: purewatersd@sandiego.gov Call: (619) 533-7572