Recycled Water Salinity Reduction Policy Utilities Advisory Commission December 2, 2009

2 Presentation Outline  Brief Review of the Palo Alto Recycled Water Project (Phase 3)  Current TDS Levels  Proposed Salinity Reduction Policy  Schedule  Questions

3 Palo Alto’s Recycled Water Project Is Phase 3 of Program Expansion RWQCP Phase 2 Phase 3 Phase 1

4 Phase 3 Project Target Market  Initially serve approximately 900 acre-feet per year (AFY), mostly in Stanford Research Park Area  Predominantly used for landscape irrigation

5 Salinity Reduction Policy: The Issue and the Need  Recycled water quality is a concern for current and potential future users of recycled water.  Salinity is one of the key attributes of recycled water of concern to users, especially with respect to its use for landscape irrigation.  Use of water by humans and businesses will add some salt, but the recycled water from the Palo Alto Regional Water Quality Control Plant appears to have higher salinity than expected.

6 TDS level comparison Salinity Reduction Policy goal

7 Current Partner TDS levels

8 Salinity Reduction Policy: What it does  In response to comments and concerns related to the proposed Recycled Water project, the Regional Water Quality Control Plant (RWQCP) and the Utilities Department have prepared a policy document to address the issue of recycled water quality  The Policy outlines the current and future efforts the RWQCP and the RWQCP partners will take to reduce the TDS concentrations to a level one would expect from a closed system.  The Policy establishes a TDS goal of 600 PPM. This goal was developed using the following assumptions:  The source water for the different agencies has very low TDS levels (~100 PPM in aggregate)  Normal, unavoidable, human activities will contribute an additional PPM to the total TDS levels  A buffer of PPM is needed since we will not be able to completely eliminate saline groundwater infiltration.

9 Salinity Reduction Policy: What it does not do  It does not have a carrot/stick approach towards meeting the goal. However, that could be a future feature.  It does not provide, nor is it based on, an assessment of what number represents a suitable TDS level for irrigation purposes. This issue will be addressed in the near future during the environmental review phase.  It does not establish a firm “delivery guarantee” for future recycled water users.

10 Implementation of the Recycled Water Salinity Reduction Policy:  The RWQCP will function as a clearinghouse for data analysis and tracking.  The RWQCP will identify issues and work with the RWQCP partners to identify and address problems that are contributing to the salinity issue.  Utilities will coordinate the new Wastewater Management Plan with the RWQCP’s efforts.  Public Works will issue a biannual progress report on the effort.

11 Future Schedule  December 2 – Utilities Advisory Commission consider recommendation on proposed Recycled Water Salinity Reduction Policy.  January – City Council will consider UAC recommendation on Salinity Reduction Policy  December to March: Utilities Staff will revisit environmental document. RWQCP will work with other RWQCP partners to submit the policy to their respective governing bodies for approval.

12 QUESTIONS?

13 BACK UP SLIDES

14 Primary Benefits To Customers and the City To Other Stakeholders  Provides reliable, locally controlled supply to offset water restrictions during droughts  Offsets need to purchase approximately 900 AFY of potable water during normal years  Reduces potable per capita consumption by 6-7%  Improves supply reliability and diversity  Advances the City’s green initiative  Contributes to Santa Clara Valley Water District meeting recycled water goal  Reduces San Francisco Public Utilities Commission reliance on imported water  Meets environmental goals of SFPUC WSIP delivery limitations  Reduces effluent discharge to the South Bay  Critical recycled water crossing U.S. Highway 101  Provides future interconnection opportunities to neighboring communities