Purified Water Quick Facts

Purified WaterQuick Facts

Water: Now and in the Future

All water is 55% $ reused. We Around the of Silicon Valley’s Cost for drink the same water world, purified water supply is imported imported water today that the water replenishes from the Sierra Nevada increases every year. dinosaurs groundwater mountains in an average did! and supplements year. drinking water supplies. QUICK FACTS

THE CHALLENGE THE SOLUTION: Purified Water! • We need water to cover future • Highly treated recycled • That’s enough growth and sustain a thriving wastewater after water to serve economy advanced treatment • We need to develop more local • Purified water to replenish 74,000 supplies to reduce our reliance our groundwater basins households on imported sources • Proposed purified water projects in Santa Clara County would produce more than

HOW IT WORKS billion gallons of water We will produce up to 8 billion gallons 8 of pure, clean water for groundwater replenishment in the near future using advanced technologies: • Microfiltration W • Reverse osmosis HAT OUR RESIDENTS GET • Ultra violet light disinfection with advanced oxidation • Reliable and locally controlled supply This process is regulated by the Division • Drought proof supply of Drinking Water under the State • Clean and safe to use Water Resources Control Board. • Cost effective • Sustainable for environment www.purewater4u.org

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

Where does the source water come from before Why is the Ultraviolet light (UV) process necessary the water is purified? if the Reverse Osmosis (RO) removes most of the contaminants and pollutants, and why is Currently, the water comes from across the street from Advanced Oxidation (AOP) needed during the the San Jose-Santa Clara Regional Wastewater Facility UV process to make it good enough to drink? as secondary treated wastewater meaning the water has already been cleaned twice and is similar to “river water.” The advanced technologies work together as a team to The facility produces recycled water that has been treated provide redundant safety back-up measures. The UV to a level that allows for its reuse for beneficial purposes. process provides disinfection and inactivation of pathogenic Within the county, there are four public wastewater organisms that may remain, sterilizing the water. The water facilities that can provide source water in the future. is very clean after UV, but adding Advanced Oxidation (a dose of hydrogen peroxide) helps oxidize the water which How is the purified water used and distributed? enhances the UV process, making the water so pure that it The water district blends the highly purified water with meets California’s strict water quality standards and is safe the recycled water produced at the wastewater facility for drinking. to enhance the quality and expand recycled water’s use Why do we need to expand the use of recycled for landscape, agricultural and industrial purposes. The and purified water? district distributes the blended recycled water through the Southbay Water Recycling Program via a purple (recycled With ongoing challenges such as reoccurring droughts, water) pipe system to more than 800 customers such as climate change, population growth and shrinking supplies Levi’s Stadium and Santa Clara University for landscaping of imported water, the water district is looking at various and industrial uses. ways to meet our demands for the 21st century. Highly purified water is a reliable and locally developed water Is the purified water produced here used supply that can be used for our future water supply needs. for drinking? Will we drink purified water in the future? At this time, the water district does not use the purified water for drinking. However, the water district plans to The district hopes to emulate the way other water district’s use the purified water to replenish our groundwater basins across the world use purified water. For example, Orange which will help augment our overall drinking water supplies County Water District in southern California (and several with more than 8 billion gallons of water. other water agencies in southern California) replenishes What is the cost comparison between running its groundwater supply with purified water. Currently, the a desalination plant and purifying reused water Santa Clara Valley Water District has the largest purified at this purification center? water facility in northern California and is proposing expansion projects and additional facilities to use highly On an annual basis, this facility costs $3.6-$5.5 million purified water. The district is exploring two potential uses dollars to operate and produce 8 million gallons per day for this highly purified water. Indirect use would replenish (MGD) of highly purified water. A desalination plant, groundwater basins to supplement drinking water supply. which purifies seawater to produce drinking water, can cost Direct use would send the highly purified water to the anywhere from $11.2- $17.6 million dollars per year to district’s drinking water treatment system. Both require operate and produce 8 MGD. In terms of energy usage, the further evaluation. 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. www.purewater4u.org