1 Update Ocean Desalination Feasibility Studies Karl Seckel Assistant General Manager

2 South Orange County Challenges n Region is 95% dependent on imported water to meet potable demand n Single water treatment plant and two pipelines supply imported water to more than 500,000 residents and businesses n Limited groundwater, surface water n Emergency outage of the imported water delivery system could cause significant problems for residents, businesses, and the economy

3 Planned Reliability Improvements n System Reliability Improvements –Lined and covered reservoirs –Interconnections –Ocean desalination n Supply Reliability Improvements –Water recycling –Water use efficiency/conservation –Groundwater recovery projects –Ocean desalination

4 Planned Reliability Improvements (cont’d) n Ocean desalination is one part of the solution – and provides two benefits: –A reliable local water source –Emergency water supply during outages of the imported delivery system

Camp Pendleton Ocean Desal Dana Point Ocean Desal Orange County Cross Connector Groundwater Emergency Service Coastal Junction Pump Connection IRWD to South County Pump Station IRWD to JTM P P P D D Diemer Filtration Plant GW Coastal Pipeline to SD County Central Pool Augmentation Project Alignments P P Lake Mathews Projects Further Out in Time: Camp Pendleton Ocean Desal Central Pool Augmentation Project Coastal Pipeline to SD County Orange County Cross $ Connector GW Emergency $15 15 Service Coastal Junction $2 20 Pump Connection IRWD to JTM $16 50 IRWD to SCPS $23 50 Dana Point Ocean Desal $? ? Total $ ± (1) (1) Project Capacities are not all additive Cost Capacity Component $M CFS SOUTH ORANGE COUNTY WATER RELIABILITY PROJECTS SOUTH ORANGE COUNTY WATER RELIABILITY PROJECTS Upper & Lower $80 32 Chiquita Reservoirs Upper Chiquita Reservoir Lower Chiquita Reservoir

6 Dana Point Ocean Desalination Subsurface Intake System n No entrainment/impingement impacts n Reduces ocean construction impacts n Improved chance for permitting approval n Pretreatment – natural sand and gravel filtration could eliminate need for costly pre-filtration step Questions to be Answered: n Capacity of intake system n Which technology to use for well intake n Power source for treatment plant n Use of existing outfall system for brine discharge

7 Working with Federal, State and Local Agencies n U.S. EPA n U.S. Bureau of Reclamation n U.S. Fish and Wildlife Service n U.S. Army Corps of Engineers n California Department of Water Resources n California State Lands Commission n California Department of Parks and Recreation n California Department of Fish and Game n California Coastal Commission n San Diego Regional Water Quality Control Board n County of Orange n City of Dana Point n South Coast Water District n Metropolitan Water District of Southern California

8 Phase 1 Exploratory Test Boring Sites Bore Hole//Monitoring Well Bore Hole Future Desalination Site SOCWA Outfall B3 B1 B2/M1 B4/M2

9 Dana Point Phase 1 Hydrogeology Conclusions n The permeability of the aquifer formation looks promising n Need information on the formations under ocean floor n Further testing needed to: –Estimate production capacity of the aquifer –Analyze water quality

10 Phase 2 Near Shore Test Drilling Approach Ocean Surface Land Surface Fresh Water 200 to 250 feet ± Slant test well Infiltration Drill Rig Ocean Bottom Main Aquifer 40 to 130 feet ± Salt Water 23 o Temporary Vault

11 Full Scale Slant Well Concept Subsurface Slant Wells & Collector Intake System SOCWA Outfall Future Desalination Plant Site

12 Slant Well Intake System Concept P Ocean Desal Plant gravity flow into caisson for ocean water intake screened slant well buried beach caisson or pipe collector pump to plant ocean surface tunneled pipeline 1500 feet± from beach pressure differential Drill Rig ocean floor beach land natural filtration

13 Questions or Comments? Karl Seckel Assistant General Manager