GWRS Final Expansion Project and SP-173 Update GWRS Steering Committee Meeting April 11, 2016

Groundwater Replenishment System (GWRS) Projects GWRS Project (Completed 2008) –Construction of 70 MGD Treatment Facility with future expansion capacities, Injection Wells, and Pipeline GWRS Initial Expansion (Completed 2015) –Expansion of 70 MGD Treatment Facility to 100 MGD including SEFE pump station & storage tanks GWRS Final Expansion (Completion TBD) –Expansion of 100 MGD Treatment Facility to 130 MGD including water supply pipeline, EQ tanks, pump station & treatment process reconfigurations at OCSD

GWRS – Advanced Water Treatment Facility (AWTF) Improvements N Microfiltration West Bldg Expansion (1.5 new trains) Six New RO Units Three New UV Trains New Product Water and BW Supply Pumps New Decarbonator and Cartridge Filter

GWRS Source Water To produce 130 MGD of GWRS water – approximately 174 MGD of Secondary Effluent is required from OCSD (including 4 MGD of GAP source water) OCSD combined Plant No. 1 & Plant No. 2 total influent flows are currently 182 MGD Santa Ana Regional Interceptor (SARI) discharges to OCSD Plant No. 2 are currently ~30 MGD OCWD is currently not permitted to use SARI source water for GWRS by the Division of Drinking Water (DDW) GWRS Expert Panel initial evaluation of recycling SARI water through GWRS deemed feasible with recommendations. DDW will have to provide approval and conditions for SARI to be recycled.

ItemFlow Ave. GWRS FE Produced 1 Current Plant No. 1 & 2 Influent182 MGD Segregated SARI Influent to Plant No MGD OCSD Plant Water Usage-2 MGD Total Flows Available for GWRS FE149 MGD111 MGD Segregated OCSD Sidestream Wasteflows (NDMA) -6 MGD MF Backwash Waste Flows16 MGD OCSD 2-72 SARI WW Diversion Projects MGD Total Flows Available for GWRS FE MGD MGD Preferred Influent for GWRS FE174 MGD130 MGD OCSD/GWRS Final Expansion Flows 1)Assumes 4 MGD Secondary Effluent for GAP and 85% RO Recovery; 2)Exact diversion flows are currently being evaluated by OCSD; 3)Potential additional source flows include Extraction Well Discharges, MF Cleaning Wastes, Additional SARI WW Diversions

GWRS Flows & Production Project GWRS Max Daily Production (MGD) GWRS Yearly Production Goal (AFY) Average Daily Production Goal (MGD) GWRS 7070, GWRS Initial Expansion ,00092 GWRS Final Expansion ,000120

OCSD Plant No. 2 OCSD Plant No. 1 OCWD GWRS Facility Santa Ana River 405 Freeway New Pump Station Exist 66-inch Pipeline to be Rehabilitated New EQ Tank

GWRS Final Expansion Implementation Plan Plant No. 1Plant No. 2

GWRS Final Expansion Preliminary Cost Estimate Project DescriptionCost (Millions) OCWD AWTF Expansion to 130 mgd$130 OCSD Plant No. 2 Pump Station$18 OCSD Plant No. 2 Six MG Flow EQ Tank$23 OCSD Slip Line existing OCSD pipeline w/ 58” HDPE$37 OCSD Plant No. 2 Headworks SARI Segregation$45 Total*$253 9 *Represents total costs for OCWD. Planned OCSD & OCWD CIP Projects not included

Initial Draft GWRS FE Project Unit Cost Estimate Financing AssumptionsUnit Cost ($/af) 1 Melded Unit Cost ($/af) 2 5% financing over 30 years – no grants obtained $980/af$567/af 1% financing over 30 years - $30 million of grants $733/af$509/af 10 1) Unit cost based on increased production of 31,000 af/year; 2) Melded unit cost combines current operating unit costs with GWRS FE unit costs for total production of 134,000 af/year

Staff to review Draft SP-173 Implementation Report in May 2016 Final SP-173 Implementation Plan complete in July 2016 OCWD Complete CEQA & Engineer’s Report to establish project in August 2016 and pursue grant funding opportunities OCSD present SP-173 findings to July Operations Committee Meeting OCSD & OCWD to prepare amendment to joint agreement –Implementation plan & each agencies responsibilities to be included Initiate MF Pilot Studies at OCSD Plant No. 2 to evaluate water quality impacts OCWD staff and GWRS Expert Panel will continue refining recommendations for recycling SARI Next Steps

End of Presentation