Purified Water Project - Ensuring a Reliable Water Supply

Oka groundwater replenishment pond near Los Gatos Creek

Status

On Target

Phase

Planning

Location

TBD pending study and partnership agreements

Valley Water must meet future water demand and identify a sustainable water supply to combat the effects of future droughts and climate change. A Potable Reuse Project will help reach those water supply goals, which include meeting at least ten percent of water demand in Santa Clara County through recycled and purified water. Pure Water Silicon Valley is envisioned to be a Direct Potable Reuse project located in San José and will allow Valley Water to develop the use of purified water to supplement existing drinking water sources in a manner that minimizes environmental impacts and protects public health.

The Valley Water Board of Directors has directed staff to develop a potable reuse project, Pure Water Silicon Valley, with the cities of San Jose and Santa Clara who own and operate the San José -Santa Clara Regional Wastewater Facility, the largest in the county.

To view the project fact sheet click here.

What is purified water? How is it different from recycled water?

Water has always been nature’s renewable resource. Purifying and recycling water simply speeds up that natural process. Recycled water generally refers to municipal wastewater that has been cleaned and meets requirements for industrial and irrigation use. Purified water is highly treated municipal wastewater that has gone through additional advanced treatment and disinfection to meet and exceed state and federal drinking water standards.

Be Heard!

To share your ideas and feedback about the Purified Water Project, please visit our online engagement site Be Heard Valley Water.

For more information:

Jiana Escobar, Community Liaison - 408-630-2266 - [email protected]
Sign up to receive project updates via email.
Learn more about Purified Water or sign up for a tour at PureWater4U.org.

What is purified water? How is it different from recycled water?

Be Heard!

To share your ideas and feedback about the Purified Water Project, please visit our online engagement site Be Heard Valley Water.

For more information:

Jiana Escobar, Community Liaison - 408-630-2266 - [email protected]
Sign up to receive project updates via email.
Learn more about Purified Water or sign up for a tour at PureWater4U.org.

General Information

Fact Sheet (Summer 2025)
Project Mailer (March 2021)
PureWater4U - Valley Water's purified water education and tour sign-up site
Recycled and Purified Water Program
Public-Private Partnership (P3) Information
Project Questions and Answers

Official Documents and Reports

Camden groundwater replenishment pond near Los Gatos Creek

Each year, record-setting temperatures and extreme weather alert us to the impact of climate change. It has never been more evident that California’s changing climate and frequent droughts threaten our natural resources. As the water resource manager for Santa Clara County, Valley Water is committed to securing and maintaining a safe, reliable water supply for our community in a sustainable manner that protects our environment. That’s why replenishing our groundwater supply with purified water, a locally-controlled and drought-resilient water supply, is a key component of that commitment. Building off the success of the Silicon Valley Advanced Water Purification Center, Valley Water will expand our water reuse efforts through recycled water technology.

Purified water produced from this project will help Valley Water meet about 10% of Santa Clara County's water demand through recycled and purified water and conserve important natural resources. The use of purified water for groundwater replenishment will help us conserve water in our rivers and streams, especially as droughts continue to occur with increasing frequency. It will also help us maintain groundwater levels and prevent overpumping of groundwater, which can cause land subsidence (sinking).

Dry Oka groundwater replenishment pond near Los Gatos Creek

The relationship between population growth, groundwater pumping, and land subsidence (sinking) over time.

Purified water is not new and meets and exceeds state and federal drinking water standards. It is used as a drinking water and groundwater replenishment source all over the United States and world, including Orange County and Monterey County in the state of California.

To learn more about how purified water is used as a drinking water source and the purification treatment process, please visit purewater4u.org. The Silicon Valley Advanced Water Purification Center offers free tours to the public that highlight the advanced water purification process, recycled and purified water, and drinkable water reuse as a locally controlled and drought-resilient water supply. Be sure to also check out this interactive world map to see how purified water is being used around the world.

About the Purified Water Project

Valley Water must meet future water demand and identify a sustainable water supply to combat the effects of future droughts and climate change. The Purified Water Project will help reach those water supply goals, which include meeting at least 10% of water demand in Santa Clara County through recycled and purified water. The project will allow Valley Water to develop the use of purified water to supplement existing drinking water sources in a manner that minimizes environmental impacts.

The Purified Water Project is proposing to build an advanced water purification facility at the former Los Altos Treatment Plant site, located on San Antonio Road in the City of Palo Alto. Purified water would be conveyed through nearly 20 miles of underground pipe to Valley Water groundwater recharge ponds in the City of Campbell.

When completed, this project will build a facility capable of providing about 10 million gallons per day of high-quality, drought-resilient water to replenish our groundwater supply for potable use in the county.

About the Purification Process - 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. As shown on the right, our purification and water treatment processes are both effective in producing safe, clean water.

How Safe is Purified Water?

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.

To learn more about how purified water is used as a drinking water source and the purification treatment process, please visit purewater4u.org. There, you can also sign up for tours of the existing Silicon Valley Advanced Water Purification Center.

Watch our public meeting!

Valley Water hosted a virtual scoping meeting for the Purified Water Project on Monday, March 29, 2021. At this meeting, staff gave an overview about the project, the planning process, and how to provide feedback related to environmental impacts that will be analyzed as part of the California Environmental Quality Act (CEQA) process. The recorded meeting and presentation slides are available below:

March 10, 2022 Well Control Zones Virtual Public Meeting