By Gabriela Rossner
The term advanced purified water refers to highly treated wastewater that has been processed at the state-of-the-art Silicon Valley Advanced Water Purification Center. At the center, treated wastewater goes through an additional high-tech three-step purification process, resulting in up to 8 million gallons per day of clean, safe water. Currently, this water is blended with recycled wastewater and distributed through the purple pipe system to expand recycled water’s use for landscape, agricultural, and irrigation purposes. In the future, the Santa Clara Valley Water District hopes to use advanced purified water to replenish our groundwater basins and augment the area’s drinking water supplies. Below, find the seven top reasons to support the continued use and expansion of advanced purified water projects.
1. Recycling water is just like recycling anything else – it is good for the environment!
We all recycle paper, aluminum cans, glass, and plastic bottles – so why not water? By recycling water, we alleviate the strain on rivers, streams, and groundwater basins.
2. Today, there exists on the planet the same amount of water as there has always been. This means that the water we drink in the 21st century is the same water that the dinosaurs used. Through the natural water cycle, all water circulates between the earth’s oceans, atmosphere, and land and is cleaned by natural processes like filtration along the way. The process used by the purification center is simply speeding up what already happens in nature.
No need to be squeamish about where your water comes from – it is important to remember that all water on the planet is reused.
3. Advanced purified water provides a reliable, locally controlled water supply.
Currently, 55 percent of the water we use is imported from the Sierra Nevada, where it begins as snowfall and rain. The majority of this water is then funneled into the Sacramento-San Joaquin Delta. Growing water demand, climate change, uncertain imported water supplies, and regulatory restrictions place pressure on our water supply. Additionally, competing water rights between municipalities and industries underscore the need for a local source of water that is controlled by our region.
4. Changing weather puts a strain on all natural resources, but especially on water. According to the United States Geological Survey, three major droughts have already occurred in California in the 21st century – from 2001-2002, 2007-2009, and most recently from 2012-2016. As frequent droughts continue to impact our area, experts from the California Department of Food and Agriculture estimate that future dry years and more droughts are certain. As such, it is imperative that our region take preemptive measures. Advanced purified water is an investment in our future – it reduces draw on vulnerable systems like the Delta and groundwater basins while reusing a valuable and finite resource.
With dramatic weather changes affecting California’s ecosystems, advanced purified water is a drought-proof resource.
5. In the spirit of Silicon Valley’s technological innovation, the purification process uses state-of-the-art multi-stage technologies to produce clean water.
The purification center receives treated wastewater from the San Jose-Santa Clara Regional Wastewater Facility, where the water has already gone through a two-step advanced cleaning process and is safe enough for release into the San Francisco Bay. At the purification center, the water is further purified using three advanced treatment processes: microfiltration, reverse osmosis, and ultraviolet light.
Microfiltration is the initial process, in which treated wastewater is pushed through membranes made up of thousands of hollow fibers with very fine pores on their sides. The pores, which are 0.1 micron in diameter, filter out solids, bacteria, protozoa, and some viruses.
The second step of the process, reverse osmosis, forces water under extremely high pressure through membrane sheets that only water can pass through. This stage removes salts, most viruses, and most contaminants of emerging concern, such as pharmaceuticals, personal care products, and pesticides.
Finally, the water is sent through chambers that emit a strong ultraviolet light to inactivate any remaining viruses and break down some of the remaining trace organic compounds. Ultraviolet light provides a powerful means of disinfection that results in water of very high quality. The technique is often used to sterilize medicines, foods and fruit juices.
6. Advanced purified water is extremely safe, as it meets or exceeds all state water reuse standards.
In order to work toward the water district’s goal of expanding purified water, the district developed the Potable Reuse Demonstration Test Plan to provide systems monitoring and water quality testing data on the purification center during its first two years of operation. The test plan thoroughly investigated the performance of each component of the purification process. The results of the testing demonstrated effective removal of all tested contaminants, such as industrial chemicals, pharmaceuticals, personal care products, and biological pathogens such as viruses, bacteria, and protozoa. These results show that the current product of the center meets or exceeds all state nonpotable reuse standards. With advanced oxidation (a fourth step currently in the pilot phase) purified water from this facility actually exceeds state drinking water standards and regulatory requirements for groundwater replenishment. Currently, purified water from the facility is blended to improve the quality of recycled water, used in our county for irrigation and industrial purposes.
7. Finally, and perhaps most importantly, it tastes great!
Over 500 people have taste-tested purified water from the purification center. The consensus is overwhelming – advanced purified water looks, smells, and tastes pure and fresh.
To learn more about advanced purified water and the Silicon Valley Advanced Water Purification Center, and to sign up for a free tour of our facilities, please visit http://www.purewater4u.org .