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 2

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 4

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 5

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 6

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 7

8.  Operate one MGD facility  San Vicente Reservoir study  Define regulatory requirements  Conduct energy & economic analysis  Public education & outreach C OMPONENTS O UTCOMES Water Purification Demonstration Project  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 9

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 10

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 11

12. Recycled Water Study Prioritized 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 12

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 13

14. Questions 14

15. Back up slides to follow 15

16. San Diego Water Reuse Timeline  1993 City & County Water Authority propose Water Repurification Project  1994Congress passes the Ocean Pollution Reduction Act, allowing the City to reapply for a waiver that is later granted  1994-1998Planning, 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 H 2 O 2 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