Net Zero Wastewater

73TOW 1The Town of Windsor is located in the Russian River Valley in Sonoma County, part of the Northern California wine country. It encompasses an area of 7.3 square miles and has a population of about 26,000. The Town is located 63 miles north of San Francisco. Windsor is known as a family-friendly destination, with a downtown area featuring many restaurants and shops, parks, and open spaces including the 4.5-acre Town Green, and frequent community events and activities. Windsor draws visitors from around the world to enjoy the area’s extraordinary natural beauty, top-notch lodging, and abundance of world-class wineries. Windsor was named one of California’s “Most Charming Towns of 2022” by the travel website Strategistico.


The Town of Windsor is a small community that is diligently working on a solution to a big issue: addressing the local impacts of climate change. One way the Town is doing this is through its efforts to attain net-zero status at its Water Reclamation Facility, which handles the treatment, storage, and disposal of the Town’s wastewater.

To accomplish this goal, Windsor is working on several projects related to the Facility to achieve net-zero power consumption, net-zero solid waste disposal, and net-zero recycled water disposal. With these projects, the Town and the region will see significant advances in sustainability. The projects will be boosted toward success through regional collaboration, distributing the benefits, and leveraging local, state, and federal funding to support our larger watershed community.

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Aeration Basin Improvements: provide enhanced wastewater treatment, improve energy efficiency, and upgrade treatment capacity

New Biosolids Handling Facility: reduce GHG emissions, stabilize costs for biosolids handling and treatment, improve biosolids quality, and utilize the biosolids byproduct biochar, which has many beneficial applications

Extend Recycled Water Irrigation System: reduce the use of potable water by bringing recycled water to the Airport Business Center area

Combine Windsor’s Facility with a Sonoma Water Facility: provide increased recycled water storage, maximize regional resources, and contribute to rate stabilization 

Implement the Russian River Reuse Collaborative: coordinate a regional approach toward water resource sustainability, improved wastewater treatment and management, reduction in duplication of efforts, and attraction of regional funding opportunities

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The Town Council Members and Staff are committed to achieving net-zero status at the Facility. This commitment is shown in how the Town has already accomplished several key sustainability efforts:

  • Building one of the largest floating solar power systems in the U.S., meeting 73% of the Facility’s energy needs.
  • Engaging with Sonoma Clean Power to discuss costs and feasibility of transitioning the Facility’s remaining power demand to achieve 100% use of clean, renewable power.
  • Entering into an agreement for the Town to utilize Sonoma Water’s excess recycled water storage, leading to significant reductions in discharge to Mark West Creek and increased use of recycled water.
  • Providing recycled water to the Vintage Greens subdivision; these are some of the first dual-plumbed homes in Northern California to use recycled water for front and backyard irrigation, making their water use sustainable by using the same amount of recycled water that each home contributes to the system.
  • Windsor sends an average of 500,000 gallons per day of its highly treated recycled water to the Geysers geothermal field where it is used to generate clean energy, producing a negative net carbon footprint.

The Town’s efforts to achieve its net-zero goals include regional partnerships and the development of a regional strategic plan. By attaining net-zero status, the Town of Windsor can become a model for other agencies and small municipalities to follow in making wastewater treatment a sustainable process.