Purified Water Quick Facts

All water is

reused. We drink the same water

today that the dinosaurs did!

Around the world, purified

water replenishes groundwater

and supplements drinking water

supplies.

$Cost for

imported water increases every year.

HOW IT WORKS We will produce up to 8 billion gallons of pure, clean water for groundwater replenishment in the near future using advanced technologies:• Microfiltration • Reverse osmosis • Ultra violet light disinfection

with advanced oxidation

This process is regulated by the Division of Drinking Water under the State Water Resources Control Board.

THE CHALLENGE • We need water to cover future

growth and sustain a thriving economy

• We need to develop more local supplies to reduce our reliance on imported sources

55%of Silicon Valley’s

water supply is imported from the Sierra Nevada mountains in an average

year.

Water: Now and in the Future

QUICK

FACT

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THE SOLUTION: Purified Water!• Highly treated recycled

wastewater after advanced treatment

• Purified water to replenish our groundwater basins

• Proposed purified water projects in Santa Clara County would produce more than

74,000 households

8 billion gallons of water

“Water should not be judged by its history, but by its quality.” Dr. Lucas van Vuuren, National Institute of Research, South Africa

WHAT OUR RESIDENTS GET • Reliable and locally controlled supply• Drought proof supply• Clean and safe to use • Cost effective• Sustainable for environment

• That’s enough water to serve

Purified Water Quick Facts

Frequently Asked Questions

www.purewater4u.org

Where does the source water come from before the water is purified? Currently, the water comes from across the street from the San Jose-Santa Clara Regional Wastewater Facility as secondary treated wastewater meaning the water has already been cleaned twice and is similar to “river water.” The facility produces recycled water that has been treated to a level that allows for its reuse for beneficial purposes. Within the county, there are four public wastewater facilities that can provide source water in the future. How is the purified water used and distributed? The water district blends the highly purified water with the recycled water produced at the wastewater facility to enhance the quality and expand recycled water’s use for landscape, agricultural and industrial purposes. The district distributes the blended recycled water through the Southbay Water Recycling Program via a purple (recycled water) pipe system to more than 800 customers such as Levi’s Stadium and Santa Clara University for landscaping and industrial uses.

Is the purified water produced here used for drinking? At this time, the water district does not use the purified water for drinking. However, the water district plans to use the purified water to replenish our groundwater basins which will help augment our overall drinking water supplies with more than 8 billion gallons of water.

What is the cost comparison between running a desalination plant and purifying reused water at this purification center?On an annual basis, this facility costs $3.6-$5.5 million dollars to operate and produce 8 million gallons per day (MGD) of highly purified water. A desalination plant, which purifies seawater to produce drinking water, can cost anywhere from $11.2- $17.6 million dollars per year to operate and produce 8 MGD. In terms of energy usage, the pressure needed to run the reverse osmosis feed pumps is 190 pounds per square inch when purifying reused water. Desalination requires the pressure to be increased to 900-5,000 pounds per square inch, which significantly increases the energy usage and costs.

Why is the Ultraviolet light (UV) process necessary if the Reverse Osmosis (RO) removes most of the contaminants and pollutants, and why is Advanced Oxidation (AOP) needed during the UV process to make it good enough to drink?The advanced technologies work together as a team to provide redundant safety back-up measures. The UV process provides disinfection and inactivation of pathogenic organisms that may remain, sterilizing the water. The water is very clean after UV, but adding Advanced Oxidation (a dose of hydrogen peroxide) helps oxidize the water which enhances the UV process, making the water so pure that it meets California’s strict water quality standards and is safe for drinking.

Why do we need to expand the use of recycled and purified water?With ongoing challenges such as reoccurring droughts, climate change, population growth and shrinking supplies of imported water, the water district is looking at various ways to meet our demands for the 21st century. Highly purified water is a reliable and locally developed water supply that can be used for our future water supply needs.

Will we drink purified water in the future? The district hopes to emulate the way other water district’s across the world use purified water. For example, Orange County Water District in southern California (and several other water agencies in southern California) replenishes its groundwater supply with purified water. Currently, the Santa Clara Valley Water District has the largest purified water facility in northern California and is proposing expansion projects and additional facilities to use highly purified water. The district is exploring two potential uses for this highly purified water. Indirect use would replenish groundwater basins to supplement drinking water supply. Direct use would send the highly purified water to the district’s drinking water treatment system. Both require further evaluation.

© 2017 Santa Clara Valley Water District • 08/2017 • NM