August 10, 2023
Santa Clara Valley Water District
Joint Recycled Water Policy Advisory Committee with the City of San Jose/Santa Clara
Sent via e-mail
Re: Sierra Club position on potable reuse in San Jose
Dear Joint Recycled Water Policy Advisory Committee,
The Sierra Club Loma Prieta Chapter is pleased to see renewed activity on the Joint Recycled Water Policy Advisory Committee with the City of San Jose/Santa Clara. We support Valley Water’s efforts to expand advanced purified water treatment in San José to provide a potable water supply that promotes self-reliance and resiliency.
You will find our Fact Sheet attached which explains why we support this project, includes relevant background information, and provides a list of recommended actions to advance potable reuse of recycled water. We are available to meet with you or your staff to discuss this information in more detail.
We look forward to participating in the process to bring potable wastewater reuse to San Jose. We encourage the Committee and your agencies to commit to move forward expeditiously to initiate the following activities:
- Coordinate on needed agreements for a Direct Potable Reuse Pilot project,
- Develop outreach and communications plans and engage stakeholders and subject matter experts, and
- Initiate a Program Feasibility Study that includes assessment of the long-term potential for potable and non-potable reuse.
Please note that this letter does not constitute support for any legislation or grant application related to this effort. The Sierra Club considers such requests on a case-by-case basis.
Sincerely,
Katja Irvin
Water Committee Co-chair
Sierra Club Loma Prieta Chapter
Cc:
Mayor Matt Mahon
Clerk of the Board, Valley Water
Kirsten Struve, Assistant Officer for Water Supply Division, Valley Water
Potable Wastewater Reuse in San Jose Will Provide Multiple Benefits
The Sierra Club supports Valley Water’s efforts to expand purification of effluent from the San José-Santa Clara Regional Wastewater Facility for potable reuse to provide a water supply that promotes self-reliance, resiliency, and resource protection. The State of California prioritizes this regional, cost-effective, and environmentally beneficial approach to stretch water supplies. Planning for the future of direct potable reuse will ensure a sustainable, drought-proof supply and reduce reliance on imported water from the San Francisco Bay Delta – which is becoming less reliable with climate change and decreasing Sierra snowpack.
Capacity for Wastewater Reuse
- The County’s four regional wastewater treatment facilities process about 140,000 acre-feet per year (AFY) of wastewater, but currently only about 11% of the treated wastewater is reused for non-potable uses such as landscaping.
- Valley Water’s near-term goal is to meet 10% of the County’s water demands with recycled water by 2025 and provide up to 11,200 AFY for potable reuse by 2028.
- Valley Water's long-term goal is 24,000 AFY of additional reuse by 2040. This could be NPR, IPR, and DPR. This will increase recycled water from six percent of water supply in 2020 to 13 percent in 2040.
- Wastewater processed at the San José-Santa Clara Regional Wastewater Facility has the potential to provide up to 24,000 AFY for potable reuse.
- Silicon Valley Advanced Water Purification Center capacity can increase from 8 to 10 million gallons per day (MGD) without expanding the footprint.
- Valley Water’s agreement with Palo Alto/Mountain View commits 9 MGD (10,000 AFY) of treated effluent to a purification facility for potable reuse.
- San Francisco Bay Area has the potential to increase water reuse to 497,000 AFY compared to 49,000 AFY currently reused.
Water Reuse Definitions
“Recycled Water ... generally refers to treated domestic wastewater used more than once before passing back into the natural water cycle.”
“Non-potable Reuse (NPR) refers to recycled water that is not used for drinking, but is safe to use for irrigation, industrial uses, or other non-drinking water purposes.”
“Potable Reuse refers to recycled water sufficiently purified through advanced treatment to meet or exceed federal and state drinking water standards ...”
“Indirect Potable Reuse (IPR) involves blending purified water with water supply in an environmental system, such as a surface water reservoir or groundwater basin, that acts as [an environmental] buffer for retaining and diluting the reuse supply before treating the blended supply.”
“Direct Potable Reuse (DPR) involves the treatment and distribution of purified water using engineering controls, without an environmental buffer, in the form of raw water augmentation or treated water augmentation.”
We Ask San Jose and Santa Clara to Work with Valley Water To
- Initiate robust public involvement. Develop outreach and communications plans and engage stakeholders and subject matter experts as soon as possible.
- Consider siting. Location of water purification facilities near sensitive bayland ecosystems will have impacts on these natural areas, and will be susceptible to sea-level rise.
- Prioritize the Program Feasibility Study. Assess the potential for potable and non-potable reuse, as well as onsite and district-scale (decentralized) NPR. Consider reduced influent due to conservation and decentralized NPR, and effluent needed to blend reverse osmosis (RO) concentrate. Evaluate alternative scenarios to inform long-term planning for expansion of potable reuse facilities.
- Enhance source control programs. Reduce contaminants of concern flowing into wastewater treatment facilities from industrial and commercial dischargers.
- Prioritize direct potable reuse. DPR could reduce costs and minimize environmental impacts due to reduced pipeline length and reduced energy use for pumping compared to IPR through groundwater recharge.
- Manage RO concentrate. Use science-based policies and procedures to mitigate potential adverse environmental impacts from disposal of RO concentrate, including ongoing attention to constituents of emerging concern such as PFAS (per- and polyfluoroalkyl substances) and microplastics.
- Monitor water quality. Continuously monitor discharges to the environment to ensure mitigation methods are preventing negative water quality impacts. Employ real-time monitoring of DPR supplies to protect public health in case of advanced treatment system failures.
References
- Sierra Club California, January 13, 2020, Sierra Club California Comments on Draft Water Resilience Portfolio.
- Santa Clara Valley Water District (SCVWD), Countywide Water Re-use Master Plan (CoRe Plan), June 2021.
- SCVWD, Water Supply Master Plan 2040, November 2019.
- SCVWD, Recycled Water Committee Agenda, Regular Meeting, Wednesday, May 24, 2023.
- Santa Clara County Medical Association, The Bulletin, Vol. 29, No.2, Second Quarter 2022.
- SCVWD, Recycled Water Committee Meeting Minutes, Regular Meeting, Wednesday, May 24, 2023.
- Pacific Institute, The Untapped Potential of California’s Urban Water Supply: Water Efficiency, Water Reuse, and Stormwater Capture, April 2022.