Zone 7’s Salt Management Plan Past, Present & Future

1. Zone 7’s Salt Management Plan Past, Present & Future Kurt Arends, P.E. AGM Engineering and Operations Zone 7 Water Agency May 9, 2012

2. Presentation Outline • Who is Zone 7 Water Agency • Existing Salt Management Plan • Challenges • SMP Outcome • Implementation progress • Current SMP efforts

3. About Zone 7: Service Area San Ramon • Service Area: 430 mi2 • Wholesale water to approx. 220,000 residents in Dublin, Pleasanton, Livermore and the parts of San Ramon • Service to four retailers • 3,500 acres of Agricultural • Groundwater Basin Manager • Regional Flood protection for Eastern Alameda County DSRSD Livermore Dublin Livermore Delta Pleasanton Pleasanton Cal Water

4. Who is Zone 7? Average Surface Water Supply: 87% of Supply via South Bay Aqueduct Arroyo Valle South Bay Aqueduct 13% of Supply via Arroyo del Valle

5. Who is Zone 7? Groundwater: Groundwater Basin Manager (over 40 years) Arroyo Las Positas 126,000 acre-feet of Operational Storage Arroyo Mocho Current Sustainable Yield:13,400 acre-feet Arroyo Valle

6. About Zone 7: Water Facilities Dougherty Reservoir PP WTP 19 mgd WELLS 40 mgd SBA DV WTP 40 mgd

7. Challenges in early 1990s • Additional water supply needed to meet projected demands • Need to expand wastewater export capacity Zone 7 and the two wastewater management agencies co-sponsored a Water Recycling Study

8. Water Recycling Study -1992 • Zone 7, City of Livermore and Dublin San Ramon Services District Completed the Study • Recognized recycled water as a viable source • Recognized need to protect the Groundwater Basin Water Quality • Master Water Recycling Permit from RWQCB • Master Permit required Salt Management Plan

9. Sources of Salt • Stream inflows • Subsurface groundwater inflow from fringe basins • Urban and Agricultural Irrigation with imported water • Adding Irrigation with Recycled Water

10. Salt Management Plan Process (1994-1999) • Zone 7 was Lead Agency • Developed through a collaborative process • Formed a Technical Advisory Group • Groundwater Management Advisory Committee • Data compilation, analysis and presentations 1994 through 1999 • In 1999, Zone 7 Board approved a Salt Management Strategy

11. Challenges during the SMP development (1994-99) • Technical challenges • Mass balance approach • How to Include All Salt Sources • Economic Challenges/Who should pay? • Users over the Main Basin vs outside the Main Basin • Existing users vs future users • Result: Groundwater Basin beneficiaries should pay

12. Challenges during the SMP development (1994-99) • Other challenges • Implementation impacts and benefits • water rates • delivered water quality • Growth vs no growth • TAG and GMAC helped formulate policy goals and recommendations to our Board

13. Adopted SMP Policy Goals -1999 • Mitigate existing and future salt loading • Maintain or Improve delivered water Quality • Provide comparable delivered water quality to all retailers • Provide a mechanism to offset salt loading associated with recycled water use • Minimize O&M cost through adaptive management process & long term goals Developing Policy goals helped screen salt management strategies

14. Analyzed SMP Strategies • Increased conjunctive Use (The Core Strategy) • Wellhead Demineralization w/ brine export • Demineralize Recycled water and Inject into GW Basin – Failed due to public opposition • Delta Fix - lower TDS import water (may improve salt balance but not in Zone 7 control) • High TDS GW export via streams – Failed due to potential downstream impacts

15. Zone 7 Board Approval and Implementation • In August 1999 Zone 7 Board approved SMP • Increased conjunctive use with wellhead demineralization • Strategy: • Mitigate existing and future salt loading • Maintain or Improve delivered water quality • Annual salt management decisions made through operations planning to provide flexibility to minimize cost and achieve long term goal

16. RWQCB Approval of SMP and Water Recycling • In June 2004, the Three co-permittees submitted the Salt Management Plan for RWQCB approval • In September 2004, RWQCB Approved the SMP

17. SMP Implementation Progress • Initiated increased conjunctive use in 2000 • In 2003 Initiated the planning and permitting for Wellhead Demineralization Facility • In 2005 prepared GWMP for the Basin and incorporated the 2004 SMP by reference

18. SMP Implementation Progress • In 2009 Wellhead Demineralization Facility came online • 6.1 MGD permeate, 1.5 MGD brine • Capital Cost ~$36M and O&M cost ~$1.5M/year • Up to 3,000-4,000 tons net salt removed/year • Full SMP Implementation needs additional recharge capacity • Use of Chain of Lakes after 2030

19. Mocho Demineralization Plant Mocho Demineralization Plant

20. Mocho Demineralization Plant Produces 6.1-million gallons per day of permeate water by Reverse Osmosis to be blended with bypass GW

21. Recent SMP Related Developments • In 2009, SWRCB Issued Recycled Water Use Policy requiring • Basins with Recycled water to have an approved SMP by May 2014 • SMPs to include Nutrient Management plans and CEC Monitoring plans • Zone 7 has RWQCB approved SMP (since 2004)

22. Recent SMP Related Developments • Zone 7 SMP needs amendment to include • Nutrient Management Plans • Monitoring plan for CEC • GW Basin Recharge area map • Plans to amend the SMP by January 2014 • Working with RWQCB and other sister agencies • Held workshop with RWQCB and agencies • Coordinating with agencies on consistent approach