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Recycled and Purified Water


As Santa Clara County faces water supply challenges driven by reoccurring droughts, growth in population and businesses, and variabilities of imported water, the water district is investing in locally reliable, sustainable, and efficient water supplies such as recycled and purified water.

The water district’s goal is to develop recycled and purified water to provide for at least 10% of the total County water demands by 2025.  To achieve this, the water district plans to develop up to 24,000 acre-feet per year (AFY) of additional highly purified water for potable reuse by the year 2025 and support continued production and expansion of recycled water. This amounts to 8 billion gallons a year of a new, drought-proof water supply, enough water to serve 74,000 households each year in Silicon Valley.

Long-term, the water district’s planning evaluates the development of up to 45,000 AFY of purified water for potable reuse.


To ensure an adequate and reliable supply of high-quality water, the water district has partnered with cities and water retailers in Santa Clara County to develop recycled and purified water supplies. In calendar year 2017, about five percent of the county’s total water use consisted of recycled water, and was used primarily for landscaping, agriculture and industrial activities.

Valley Water, in collaboration with local stakeholders, is developing a Countywide Water Reuse Master Plan, a collaborative strategy to integrate and expand recycled and purified water as a local, reliable, environmentally adaptive, drought-resilient water supply. This master plan is estimated to be completed by Summer 2021.

There are four individual Recycled Water Systems (RWS) providing service in Santa Clara County. These systems receive recycled water from a single Producer (City of Sunnyvale, Palo Alto Regional Water Quality Control Plant (RWQCP), South Bay Water Recycling (SBWR), and South County Regional Wastewater Authority(SCRWA)).

Additional information pertaining to each of these systems:

City of Sunnyvale - RWS



South County RWS

  • 2015 South County Recycled Water Master Plan Update

What is recycled water?

Recycled water is wastewater that is cleaned through multiple levels of treatment.

Recycled water is clean and safe. Recycled water is treated to strict standards set by the Division of Drinking Water and is rigorously monitored by local, state, and federal agencies to ensure it continuously meets those standards.

All recycled water in Santa Clara County meets or exceeds standards set by the state for the various uses of recycled water.

Various uses of non-potable recycled water include irrigation, industrial, and agricultural uses.

Water has naturally been recycled through the earth’s water cycle for millions of years. During the past 200 or so years, what has been termed “unplanned recycling” has occurred. This consists of upstream cities discharging their treated wastewater to a river or other waterway from which downstream cities obtain water for treatment to drinking water standards. For example, the Sacramento River receives treated wastewater and also serves as a water source for many towns and cities.

Benefits of recycled water:

  • Conserves drinking water supplies.
  • Provides a dependable, drought-proof, all-weather, and locally-controlled water supply.
  • Helps restore and preserve our saltwater and tidal habitats by reducing freshwater discharge to the Bay.
  • Is more economical and environmentally sustainable because it is less energy-intensive and has a lower carbon footprint than many other water supply sources 

Read more in "Watts to Water" (PDF)

What is purified water?

Water has always been nature’s renewable resource and is constantly moving through the water cycle. Purifying water simply speeds up that natural process by using a multistep effort to remove potential water contaminants, creating a drought-resilient and sustainable water source. Purified water first starts out as highly treated wastewater that has already gone through a multi-step treatment process at a wastewater facility. Once that highly treated wastewater arrives at our treatment facility, it goes through a multi-step purification process, which can include micro-filtration, reverse osmosis, and UV light disinfection and advanced oxidation. This purified water is treated to strict standards set by the Division of Drinking Water and is rigorously monitored by local, state and federal agencies to ensure it continuously meets those standards. All purified water in Santa Clara County meets or exceeds standards set by the state.

How Safe is Purified Water?

As mentioned, purified water is safe and meets or exceeds state and federal drinking water standards. It is tested regularly by our certified Water Quality Lab to ensure safety and quality. Upon completion of the Purified Water Project, Valley Water will be able to use purified water to add to our groundwater replenishment efforts. Valley Water will join many other places in the United States and worldwide in using this water purification and replenishment method, including Monterey and Orange counties in California, Texas, Australia and Singapore.

The Silicon Valley Advanced Water Purification Center (SVAWPC) and the Purified Water Project

To learn more about how purified water is used as a drinking water source and the purification treatment process, please visit There, you can also sign up for tours of the existing SVAWPC, which currently produces up to eight million gallons per day of highly purified water.

This highly purified water is blended into existing recycled water provided by SBWR, which improves overall recycled water quality so that the water can be used for a wider variety of irrigation and industrial purposes. In the future, Valley Water is planning to expand purified water use into groundwater replenishment, similar to the highly successful groundwater replenishment system that has been operated by the Orange County Water District for over 30 years.

For more information about this effort, please visit the Purified Water Project website.

For more information, contact the Santa Clara Valley Water District via our online Access Valley Water system, or call 408-630-3533.