Protect The Russian River Watershed
City Manager David Kelley
The City of Cloverdale is taking critical steps to protect the Russian River Watershed and its water supply by initiating a Recycled Water Planning Study aimed at assessing the feasibility of producing recycled water for non-potable reuse, not used for drinking but for irrigation, industrial, and commercial purposes.
Improving Water Supply Resiliency with Recycled Water Feasibility Study
Cloverdale aims to improve the City’s water supply resiliency through the recycled water planning study. The project will assess the feasibility of producing recycled water at the City’s Wastewater Treatment Plant using advanced treatment processes to produce high-quality effluent that can be safely discharged into the environment and reused for non-potable reuse purposes, such as irrigation, commercial/industrial processes, or toilet flushing and thereby offsetting the use of potable water.
What Does the City Currently Do with its Wastewater?
The City currently receives and treats approximately 730,000 gallons of wastewater per day. After treating the wastewater sufficiently to ensure no harm is done to the surrounding environment or human health, the wastewater is discharged to ponds located adjacent to the City’s Wastewater Treatment Plant. The treated wastewater, known as effluent, seeps into the soil and recharges groundwater.
What is Non-potable Reuse?
Non-potable reuse is reclaimed water not used for drinking, but safe for other non-drinking water purposes. The advanced treatment process involves a combination of physical, chemical, and biological processes, that typically includes filtration, disinfection, nutrient removal and adsorption. The specific processes used in advanced treatment depend on the desired effluent quality, the type of wastewater being treated, and the intended reuse or discharge destination. Advanced treatment can be a complex and expensive process, but it is an important step in protecting public health and the environment by reducing pollution and conserving/offsetting potable (fresh) water resources.
How is the Recycled Water Study going to be Funded?
The City Council authorized and directed City staff to apply for a USBR WaterSmart Grant to cover a significant portion of the project planning costs. In addition, the City is pursuing a planning grant with the SWRCB. Together, the two grants could pay for most or all costs of studying the potential for recycled water for the City and the region. The City anticipates hearing back from the USBR this summer and from the SWRCB closer to the end of the year.
The City of Cloverdale is collaborating with other Sonoma County Cities through the Russian River Reuse Collaborative to reuse water in the region for resiliency and sustainability. Both Healdsburg and Windsor have already transitioned to advanced treatment processes at their respective wastewater facilities. This partnership helps the City be more competitive for federal and state funding opportunities.
Planning Project Milestones
The planning project is expected to have two major milestones, a Recycled Water Feasibility Study followed by preliminary engineering design.
Recycled Water Feasibility Study. The Feasibility Study will include the following tasks:
1. Recycled Water Demand Assessment – estimating recycled water demand by identifying potential recycled water uses.
2. Treatment Facility Recommendations – identifying the recycled water treatment facilities needed to produce recycled water that meets all State standards
3. Distribution System Analysis – evaluating the most efficient layout and sizes of recycled water infrastructure, including pipelines, tanks, and pumps to serve recycled water customers
4. Construction Financing Plan and Revenue Program – determining additional funding sources for the construction and operation of the recycled water project
Preliminary Engineering Design
After completion of the Recycled Water Feasibility Study, preliminary engineering design will begin for wastewater treatment plant upgrades and the recycled water distribution system. During this stage, engineers will determine the appropriate treatment technologies and distribution system components based on the results of the feasibility study. Overall, the preliminary engineering design process for wastewater treatment plant upgrades and the
recycled water distribution system is a critical step towards the construction of a sustainable and reliable recycled water system. The process ensures that the system is well designed, compliant with regulations, cost-effective, and able to meet the demands of the community it serves.
Project Benefits and Beneficial Uses
By constructing additional treatment facilities at the existing wastewater treatment plant, the advanced treated effluent can be used for many non-potable uses instead of simply letting it go unused. Cloverdale and the surrounding area could instead use this recycled water for many non-potable uses governed by the State’s recycled water regulations, such as:
• Agricultural irrigation – Tertiary treated water can be used for agricultural irrigation instead of using potable water. This can help to conserve potable water resources and reduce the strain on local water supplies.
• Landscape irrigation – According to the United States Environmental Protection Agency (EPA), landscape irrigation accounts for nearly one-third of all residential water use in the United States. Additionally, in arid regions, like California, outdoor water use for irrigation can be much higher, accounting for up to 50% or more of residential water use. Using recycled water for landscape irrigation can greatly reduce the amount of potable water needed for this purpose and help to conserve valuable drinking water resources.
• Fill stations for customer pick-up,
• Construction use – Tertiary treated water can be used for dust control or soil compaction during construction projects. This can help to reduce the need for potable water and minimize the environmental impact of the construction site.
• Commercial and industrial uses – Industries that require large volumes of water, such as manufacturing or power generation, can use tertiary treated water for non-potable purposes such as cooling towers or boiler feed water. This can help to reduce their reliance on potable water and decrease their overall water usage.
During the Recycled Water Demand Assessment, the City will work with the community and potential recycled water customers, such as large irrigation users, to gauge interest in recycled water. Community outreach is essential during the preliminary design phase to inform and educate the public about the proposed project. This outreach helps to address any concerns or questions that may arise from the community regarding the project. Recycled water can be beneficial for nearby agriculture by supplementing current water supplies, especially during periods of drought and mandatory water restrictions. Cloverdale residents could also benefit by having a new drought-resilient water source for landscape irrigation and other non-potable uses.
While recycled water can be used instead of drinking water for non-potable uses like landscape irrigation, the City continues to encourage water conservation. Recycled water can be one of the City’s tools to be used in conjunction with water conservation to improve water supply reliability.
Project Cost and Schedule
The estimated cost of completing the planning project is $1,155,000. The City requested $577,500 in funding from the USBR WATERSMART: Water Recycling and Desalination Planning Grant and will be applying for up to $500,000 from the SWRCB Water Recycling Funding Program. By utilizing grant funding now, the City will minimize the need for future rate increases to complete the project. Additionally, the City will receive the ultimate benefits of offsetting millions of gallons of drinking water per year to meet water supply needs in the region.
The City will start the study upon securing the necessary grant funding to cover the cost of the project. Assuming both the State and Federal grants are successful, the City would have up to $1 million in external funding for recycled water planning efforts.
The feasibility study is slated to begin in August 2023, depending on funding awards. The preliminary engineering is planned to begin in August 2024 and be completed in October 2025. Full project implementation and construction could take up to ten years.
The City encourages water conservation and uses recycled water as a tool to improve water supply reliability. Contact David Kelley, City Manager, for more information. Find general information about recycled water at:
https://www.waterboards.ca.gov/water_issues/programs/recycled_water/
