Recycled Water FAQs

Frequently Asked Questions: Recycled Water in Windsor

What is recycled water?

Recycled water is wastewater from homes and businesses that has been carefully treated to be safe for a variety of beneficial uses.  

Is recycled water safe?

Yes. Recycled water is regulated by the California State Water Resources Control Board and Windsor treats its water to a level that the State of California certifies is safe for all uses except to drink.

How is the water processed for safe reuse?

Wastewater undergoes a three-step treatment process, ending in sand filtration and ultraviolet disinfection, to ensure our recycled water is safe and approved for uses including crop and landscape irrigation, dust control, decorative fountains, toilet flushing and more!  Recycled water is strictly regulated by the State Water Resources Control Board under Title 22 of the California Code of Regulations and Windsor produces tertiary-treated recycled water, a high standard of wastewater treatment.   

Why and where is recycled water used in Windsor?

The Town of Windsor uses recycled water to offset urban and agricultural potable water demands.  Areas where recycled water is used for landscape irrigation include Windsor High School, the Vintage Oaks subdivision, Fire Station #3, many Town parks, the Windsor Town Green, local vineyards and pastures, and the Windsor Golf Course.   Recycled water is also used for toilet flushing at Windsor High School and Fire Station #3 on Windsor Road.

Where does Windsor get its recycled water? 

Windsor’s recycled water comes from the wastewater generated by Windsor residents and businesses.  When you take a shower, wash dishes, use the bathroom or do laundry, your wastewater is sent through the sewer system to the wastewater treatment plant where it is treated to produce high quality, tertiary treated recycled water.

Who can use Windsor’s recycled water?

Recycled water service is available to residents in areas where recycled-water infrastructure is established, and distribution piping is accessible. For example, residents in the Vintage Oaks subdivision, a newer neighborhood compared with others in Windsor, can use recycled water since it was built with that infrastructure. In such areas, users who want to connect to recycled water must obtain a recycled water permit from the Town and receive user training.   

Some local businesses, including vineyards, also use recycled water. Recycled water is also available to development/road contractors at the Public Works Department fill station for construction dust control and other industrial uses. The Town is currently looking into establishing a filling station available for residential use. 

Why is recycled water not available throughout Windsor?

Recycled water must be delivered via dedicated recycled water pipes. While Windsor has an extensive recycled water distribution system, this system is not developed for service throughout the community.

How long has recycled water been in use in Windsor?

Windsor began producing and delivering recycled water in 1991.  The wastewater treatment facility has been upgraded and expanded over the years to improve treatment, storage, and reuse.

How much recycled water does Windsor create each year?

Windsor residents and businesses generate approximately 1.5 million gallons of wastewater per day that the Town treats to high-quality standards for recycled water.  In a typical year, Windsor re-uses about one-third of its treated wastewater for landscape and crop/pasture irrigation and toilets, one-third is sent to the Geysers Steam Fields for sustainable power generation to benefit the larger Sonoma County community, and one-third is discharged to Mark West Creek during the wet weather season.   

How much recycled water does Windsor expend each year?

Each year, Windsor distributes approximately 200 million gallons of recycled water for residential landscape irrigation, crop and pasture irrigation, irrigation at the Windsor Golf Course, toilet flushing at Windsor High School and Windsor Fire Station #3, dust control and filling the Windsor Town Green fountain, among other approved uses. This use of recycled water directly offsets potable water consumption -- a great benefit to our water conservation efforts!

Is recycled water cheaper to use than potable water?

Yes. Recycled water rates are generally cheaper than potable water.   The Town’s current rates for potable water and recycled water can be found on the Town’s website: Rates | Windsor, CA - Official Website (

Why doesn’t Windsor recycle all its wastewater?

Ideally, Windsor would use all its wastewater for beneficial reuse, such as landscape irrigation, indoor plumbing, or energy generation at the Geysers Steam Fields. However, Windsor can only store up to 140 million gallons of wastewater in our recycled-water ponds. In the winter, when our storage ponds are full, excess water is treated to the high-quality standards, then discharged to Mark West Creek.   Windsor staff are continually looking for strategies to maximize recycled water storage, including developing regional partnerships for recycled water storage. 

What happens if we drink recycled water, or my dog does?

Recycled water is not approved for human consumption. While ingestion of recycled water will not harm pets, wildlife and farm animals, this use is not recommended.

Can recycled water be used in swimming pools and spas?

Although the Town’s recycled water is approved for full body contact (immersion) and fish life, the Town does not permit its use in swimming pools and spas. Rather, the Town is trying to irrigate urban landscapes, including street medians, with recycled water wherever possible. Landscape irrigation uses the most water during peak demand periods. So, leveraging recycled water is the most practical use of recycled water and preserves our limited potable water supply.