pure pure WATER TECHNOLOGY Purifying Water for a Sustainable Tomorrow

Transcription

1 pure WATER pure TECHNOLOGY Microf iltration Purifying Water for a Sustainable Tomorrow Reverse Osmosis Ultraviolet Light

2 Leading the way Water is life. At the Santa Clara Valley Water District, we recognize that a safe, clean and reliable water supply is crucial to sustaining the Silicon Valley economy and quality of life. Growing water demand, uncertain imported water supplies, the present and recurring droughts, regulatory restrictions and climate change require agencies like ours to both promote the wise use of water and find additional supplies to fill projected future water supply demands. As we learned in the 5th grade, the water cycle moves water through different states continually, but new water is not created. So we must employ the latest technologies to ensure we can clean and reuse our limited supplies. It is why we take such pride in opening the new Silicon Valley Advanced Water Purification Center. With our partner cities of San José and Santa Clara, the water district has built a $72 million state-of-the-art facility that produces up to 8 million gallons per day of highly purified water from treated wastewater, sourced from the San José-Santa Clara Regional Wastewater Facility. This advanced purified water will be blended with existing recycled water supplies to enhance its quality and potential uses. This facility, the largest of its kind in Northern California, will also demonstrate and showcase that proven technologies exist to produce purified water than can potentially be used to augment future drinking water supplies. These projects do not materialize overnight. I would like to thank the forward-looking board members and staff of the water district. Because of them, we were recently honored as the large agency of the year by the WateReuse CA association. We are committed to continuing to work with our partners to push the sustainability envelope in order to provide clean, safe water to current and future generations. Tony Estremera Chair, Board of Directors, Sant Clara Valley Water District It is with pleasure that I acknowledge the City of San José s support for expanding recycled water throughout Santa Clara County. A safe, clean and reliable water supply is crucial to sustaining Silicon Valley s economy and quality of life. However, this water supply is facing a number of challenges, including growing water demand, uncertain imported water supplies, recurring droughts, regulatory restrictions and climate change. While water conservation can help meet future water supply demands, it is not enough. What we need is a local, reliable and sustainable water supply that is available in dry as well as wet years. This is essential to sustaining our businesses, institutions, economy and way of life. We are excited that the Silicon Valley Advanced Water Purification Center will not only enhance the quality of recycled water, but also demonstrate proven technologies that are available locally to produce purified water for a variety of potential future uses including potentially using purified water to augment drinking water supplies. As a recycled water partner with the District, the City of San José supports their efforts to provide water for today and tomorrow from the best sources, using the most appropriate purification technologies. Sincerely, Chuck Reed Mayor, City of San José Recycled water has been an integral part of Santa Clara s water supply portfolio since the late 1980s and is currently used for landscape irrigation, cooling towers, industrial process water, and for flushing toilets in dual-plumbed buildings. Last year, Santa Clara s customers used 1.2 billion gallons of recycled water, which is over 15% of the water sold in the City. It is for this long-term commitment and investment that the city of Santa Clara was recently honored by WateReuse CA for Excellence in Water Recycling for a medium-sized city. We are pleased to partner with the city of San José and Santa Clara Valley Water District on the region s recycled water infrastructure in order to provide high quality recycled water for today and to help meet future water needs. Sincerely, Jamie L. Mathews, Mayor, City of Santa Clara 2

3 Our commitment to the public Established in 1929, the Santa Clara Valley Water District manages an integrated water resources system to supply clean, reliable water and provide flood protection and stewardship of streams on behalf of Santa Clara County s 1.9 million residents. We partner with 13 local water providers who use our treated water and groundwater basins, along with other sources, to deliver drinking water directly to homes and businesses in the county s 15 cities and unincorporated areas and provide conservation programs for their communities. We also serve 4,700 well owners. The water district does all this by effectively managing 10 dams and surface water reservoirs, imported water supplies, three water treatment plants, an advanced water purification facility, a state-of-theart water quality laboratory, nearly 400 acres of groundwater recharge ponds and more than 275 miles of streams. We serve the cities of Campbell, Cupertino, Gilroy, Los Altos, Milpitas, Monte Sereno, Morgan Hill, Mountain View, Palo Alto, San José, Santa Clara, Saratoga and Sunnyvale and the towns of Los Altos Hills and Los Gatos. The district, governed by a sevenmember elected board of directors, is one of the few water agencies in the state that manage both water supply and flood protection, while also serving as a watershed steward. This comprehensive and integrated approach is advantageous because it allows the district to plan for and manage projects in a way that achieves multiple benefits. For example, while managing the water supply in the reservoirs, the district also considers the environment, wildlife habitat and flood risks. District mission Provide Silicon Valley safe, clean water for a healthy life, environment, and economy. Our highest-level priorities encompass three board policies: Reliable, Clean Water There is a reliable, clean water supply for current and future generations. Natural Flood Protection There is a healthy and safe environment for residents, business, visitors and future generations. Santa Clara Valley Water District BY THE NUMBERS 15 cities served 13 local water providers served 1.9 million residents served 200,000 commuters served 469 million-dollar budget 3 pumping plants 1 advanced water purification plant 191,000 acre-feet (AF) of water imported in ,000 AF of groundwater recharged in reservoirs 169,000 AF combined capacity of reservoirs 3 treatment plants 126,000 AF delivered in miles of streams maintained 378,000 AF approximate county usage in miles of pipelines 58,000 AF of water saved through conservation measures Healthy Creeks and Ecosystems Protecting Downtown San Jose There is stewardship of our water resources to protect and enhance watersheds and natural resources and to improve the quality of life in Santa Clara County. Pajaro Basin Wetland 3

4 Water supply: Past, present and future Providing clean, reliable water Water is the lifeblood of the bustling and ever-changing Santa Clara Valley that has transformed from the Valley of Heart s Delight to the global economic and technological engine called Silicon Valley. In the early 1900s, the valley was one of the state s prolific producers of fruits, nuts and vegetables. Its water supply depended on pumping groundwater. As the demand for produce increased nationwide, so did the land under cultivation, resulting in deeper wells, higher pumping costs and sections of the valley floor actually sinking or subsiding. In fact, parts of San José sank approximately 13 feet. The sinking water table also allowed salty bay water to intrude into streams and aquifers, causing wells near the shoreline to become brackish. Concerned about subsidence and wells drying up, farmers and business leaders established the Santa Clara Valley Water Conservation District in 1929; then formulated an innovative plan to build reservoirs to capture rainwater and percolate it into the aquifers through percolation ponds along streams throughout the county. Anderson Dam Spillway Construction, 1951 By the 1950s, there was a comprehensive system of reservoirs and percolation ponds, earning applause in the civil engineering world and designated a historical landmark in 1976 by the American Society of Civil Engineers. Imported water meets growing local demand Explosive post-war growth, combined with a major drought from , severely strained local water resources. By 1952, two more reservoirs Anderson and Lexington were completed, more than tripling the system s storage. However, local water officials knew that local water alone could not meet the valley s growing demand. First water passes through Pacheco Tunnel, 1981 In 1965, with the construction of the South Bay Aqueduct, the county began receiving State Water Project (SWP) water to recharge the groundwater. In 1967, water imported from Lenihan Dam outlet modification, 2008 Ongoing infrastructure maintenance 4

5 Over 165,000 water quality tests completed in 2013 Rinconada Water Treatment Plant SWP began flowing to the valley s first drinking water plant, the Rinconada Water Treatment Plant. Two more treatment plants Penitencia and Santa Teresa and an extensive in-county distribution network were added over the next two decades. Meanwhile, with the completion of San Felipe project in 1987, the first Central Valley Project (CVP) water poured from the San Luis Reservoir into the Calero Reservoir. The value of imported water was underscored in 1989, when in the middle of the statewide droughts, 90 percent of our water supply came through these systems. Providing water for today and tomorrow Today, the complex water supply system includes 10 dams and surface water reservoirs, three drinking water plants, three pumping plants, 140 miles of large transmission pipelines, a state-of-the-art water quality laboratory and nearly 400 acres of groundwater recharge ponds. However, we face a number of challenges in providing a reliable water supply. These include aging infrastructure, a growing water demand, uncertain imported water supplies, recurring droughts, regulatory restrictions and climate change. Installing a valve at a water pipeline The district is making significant investments to repair and rebuild original infrastructure, including seismic retrofits at dams, such as Anderson, and improvements to water treatment plants, like the ones planned for the Rinconada Water Treatment Plant. We must also continue to innovate and adapt to changing conditions and explore and develop new technologies and best practices around water storage and groundwater banking, conservation and water recycling. With the opening of the Silicon Valley Advanced Water Purification Center, the district has joined other innovative cities and water agencies that are utilizing advanced water purification technologies to purify water for various uses. Our understanding of how to purify and reuse water will ensure a sustainable future, enabling us to continue to prosper as a region for generations to come. Photo by Charles Hearn Silicon Valley Advanced Water Purification Center under construction Silicon Valley Advanced Water Purification Center,

6 Paid Advertisement Now Open Silicon Valley Advanced Water Purification Center Th The state-of-the-art facility takes treated wastewater that would have otherwise been discharged into the San Francisco Bay and purifies it by using three proven purification processes: microfiltration, reverse osmosis and ultraviolet light. The result is 8 million gallons a day of highly purified water that is expected to match California drinking water standards. The $72 million purification center is a partnership between the Santa Clara Valley Water District and the cities of San José and Santa Clara. The highly purified water produced at the new purification center is being blended with the recycled water produced at the neighboring San José- Santa Clara Regional Wastewater Facility to enhance its quality and expand its usage via the South Bay Water Recycling system. Total dissolved solids (TDS) is a good water quality marker and it s the Tertiary treated recycled water (2013 avg.) 40 key factor that non-potable recycled water users are concerned with. The highly purified water produced at the purification center has an average TDS concentration of around 40 milligrams per liter. The addition of this purified water to recycled water is reducing the recycled water TDS levels from the average of 750 mg/l in 2013 to the targeted 500 mg/l, thus making a good product even better. This enhancement in water quality will allow for a wider use of recycled water for a variety of purposes, such as irrigation, commercial and industrial. For example, with lower TDS, industrial customers would require less pre-treatment to avoid scaling, while landscape users would see a reduction in leaching to remove excess salt from the soil. The center will demonstrate proven technologies to produce highly purified water that can be used for a variety of purposes, including potentially expanding Silicon Valley s future drinking water supplies. Total dissolved solids (TDS) in Santa Clara County water sources (mg/l) SVAWPC target Benefts of the project Expected TDS after 2:1 blend 215 Treated drinking water (typical average in Santa Clara County) Recommended secondary maximum contaminant limit for drinking water Enhances recycled water quality Creates a locally controlled, high quality water supply Increases water reliability by providing purified water at all times, even during droughts Helps reduce dependency on water from the Sacramento-San Joaquin Delta Protects the region s groundwater supplies and quality Protects the environment by reusing a precious resource Reduces wastewater discharge to the San Francisco Bay and preserves the natural tidal habitat The purifcation processes The purification center uses technology similar to Mother N process, but with the advantage of purifying the water mo The processes used at the purification center and other comparab successfully used to produce clean, safe drinking water throughou MICROFILTRATION In this initial filtration process, treated wastewater is forced through filtration membrane modules made up of thousands of hollow fibers, similar to straws. These fibers have very fine pores in the sides that are 0.1 micron in diameter, or about 1/300th the width of human hair. As the water is drawn through the pores into the center of the fibers, solids, ba some viruses are filtered out of the water. REVERSE OSMOSIS During the reverse osmosis (RO) process, water is forced under high pressure through membrane sheets with holes so small that a water molecule is almost the only substance that can pass through. The process removes constituents such as salts, viruses and most contaminants of emerging concern, such as pharmaceuticals, personal care products and p 240 RO pressure vessels currently installed that will produce 8 mi (approximately 9,000 acre-feet per year) of high-quality water. ULTRAVIOLET LIGHT Now the water is very clean, but as a further safety back-up, the water is sent through chambers that emit strong ultraviolet light to inactivate any remaining viruses and break down some of the remaining trace organic compounds. Ultraviolet light is a powerful disinfection process that creates water of very high quality. The technique is often medicines, food and fruit juices. The new facility has received $8.25 million from the federal A and Reinvestment Act and $5.25 million from the Californ Water Resources. 6

7 July 12, 2013 e largest plant of its kind in Northern California. A tour of the facility ature s filtration re quickly. le processes are t the world Intake pumps Microfiltration process Inter-process tank & transfer pumps Reverse osmosis feed pumps Start Visitor center Parking cteria, protozoa and W E S N 1 Purification chemicals 3 Microfiltration Reverse osmosis 4 esticides. There are llion gallons per day Highly purified water storage tank 8 2 Control room 5 Ultraviolet light 7 6 Reverse osmosis process Decarbonation towers Ultraviolet light disinfection process Highly purified water storage tank used to sterilizes merican Recovery ia Department of 7

8 Frequently asked questions Is recycled water already used in the county? Why do we need to expand the use of recycled water? What specifc steps is the water district taking to expand recycled water use? Yes. Recycled water has been successfully used in Santa Clara County since the 1970s and currently comprises almost 5 percent of the county s water supply mix. Tertiary-treated recycled water is used for a variety of non-drinking purposes such as landscaping, agriculture and industrial uses. The water district is responsible for securing, managing and delivering a safe and reliable water supply to the region. Searching for sustainable local water supply sources that match the right quality with the right use is part of that responsibility. Santa Clara Valley needs additional supplies to fill projected future water supply shortfalls. Highly purified recycled water is one new, locally developed and reliable water supply. Provided through proven technologies, it is a drought-proof water supply that can help ensure the valley has safe, sustainable water now and into the future. By using water that would typically be released into the San Francisco Bay, we also benefit from a local resource. Freshwater discharge to the Bay can also impact sensitive salt marsh habitat. In addition, recycled water is a locally controlled source, unlike imported water. The Santa Clara Valley Water District has partnered with the cities of San José and Santa Clara to build the Silicon Valley Advanced Water Purification Center, a stateof-the-art facility to help meet Santa Clara County s future water needs. This allows the water district to apply proven technologies to produce purified water, expanding the options for recycled water uses throughout the region. The $72 million purification center in San José will produce up to 8 million gallons of highly purified water per day, making it the largest advanced water purification plant in northern California. Why can t we just conserve enough water to meet future needs? Water conservation will remain important to preserving the county s precious water supplies. Since the late 1980s, the county s population has increased by about 25 percent, while our water use has remained relatively flat despite a growing economy. However, conservation alone is not enough to meet our current and future water needs. Climate change, recurring droughts and regulatory restrictions all place growing pressures on the state s water supplies and underline the need for new sources of water. Our current sources, combined with expanded water conservation and recycling, are necessary if Silicon Valley is to continue to thrive. 8

9 about advanced water purifcation Will we be drinking recycled water in the future? Isn t recycled water already part of our drinking water supply? Is recycled water safe for use? At this time the purified water is being blended with the water produced at the San José-Santa Clara Regional Wastewater Facility. This enhances the quality of the recycled water produced there, which will expand the number of recycled water customers using the water for non-drinking purposes. The purification center will demonstrate proven technologies that are available locally to produce highly purified water that can be used for various purposes, including expanding future drinking water supplies. In the future, the district may evaluate additional uses for the purified water similar to that being done by other water districts in the state. Orange County Water District in Southern California recharges its groundwater supply with purified recycled water. The water purified at their Groundwater Replenishment System is the purest water source available, and actually improves groundwater quality. No decision has been made to implement such a project locally. Such a decision would only be made after an extensive public engagement process. The water we use today has been used over and over again, cycled through land, ocean and atmosphere in the water cycle. Our water has been reused over the centuries, but also more recently. In our county, about 40 percent of the water used is imported through the Sacramento- San Joaquin Delta. While nearly all of this water is directly from rainfall and snowmelt, a small percentage is used by several cities on its way to us and is returned to the system. Our Delta water supplies are treated at one of our three drinking water treatment plants or filtered through groundwater recharge, making it safe to drink. Yes, the California Department of Public Health allows irrigation and industrial uses of recycled water and even full body contact with recycled water that is part of a recreational lake. However, water from the new Silicon Valley Advanced Water Purification Center will be even purer than tertiary-treated (traditional) recycled water. In fact, highly purified water produced at the center is expected to match drinking water standards. 9

10 Where in the world is advanced purifed water? We are excited to see that your Silicon Valley Advanced Water Purification Center will not only enhance the quality of recycled water, but also demonstrate proven technologies that are available to us locally to produce purified water for a variety of potential future uses including using purified water to augment drinking water supplies, i.e., potable reuse. We also encourage the Board (Santa Clara Valley Water District) to expand efforts for stormwater capture, treatment and recharge of local aquifers. We support the water district in its efforts to provide water for today and tomorrow from the best sources, using the most appropriate purification technologies. Richard G. Luthy, Ph.D. Professor and Director, Engineering Research Center for Re-inventing Urban Water Infrastructure, Stanford University Essex Suffolk, London Wulpen Belgium During the 20th century we constructed large public works Aurora, CO to impound water and transport it to our rapidly growing nation. But that Orange County, CA classic approach to supplying water Los Angeles, CA has about reached its limit. We haven t Long Beach, CA significantly increased the total capacity of San Diego, CA our impoundments since Increasingly, the Scottsdale, AZ need for a healthy ecosystem limits the amount of water we can take for our own use, Cloudcroft, NM and global warming threatens to limit us even more. At the same time the U.S. population continues to climb. Clearly we must make more effective use of the water we have. Fortunately we know more about water now than we ever did before both how to purify it and how to measure its purity. Just when we have learned how to recycle water and make it safe to drink, we have also reached a point in history when we must reuse water to maintain our quality of life. R. Rhodes Trussell, Ph.D. Chairman, National Research Council Panel on Reuse El Paso, TX Big Springs, TX New York City, NY Upper Occoquan, Washington DC Clayton County, Atlanta, GA Water has been reused continuously throughout history, by means of natural processes. Otherwise the earth would have run out of water thousands of years ago! Nowadays we have the technology to simulate natural processes, only more quickly. And we can produce water that usually is better than water from conventional sources. The poorer the water source, the better the technology needed to produce water that is suitable and safe for its intended use, whether that is cooling, irrigation, or drinking. Joseph Cotruvo, Ph.D. President, Joseph Cotruvo and Associates LLC, Chairman of the Regulatory Committee of the WateReuse Association 10

11 LEGEND Communities reusing water through advanced technologies, creating a drought-proof, sustainable drinking water supply Communities currently demonstrating advanced water purification technologies Recycled water is a new drought-resistant supply that can sustain our businesses, institutions, economy, and high quality of life. The Silicon Valley Advanced Water Purification Center is proof that locally-available tertiary treated water can be processed into highly purified recycled water with many potential future uses including the augmentation of drinking water supplies. Direct and indirect potable reuse applications offer the most promise and complement the region s current efforts to maximize recycled water use. Richard Roth Chairman, President and Chief Executive Officer, San Jose Water Company Water reclamation using the newest and best technology is needed if we are to maintain our quality of life and the planet. Just as important is improved monitoring, which will assure the public and keep water scientists and health experts on their continued journey in providing us with safe water. Joan Rose, Ph.D. Homer Nowlin Chair of Water Research at Michigan State University; Co-director of Center for Advancing Microbial Risk Assessment and Center for Water Sciences Windhoek, Namibia Singapore The Western Corridor Recycled Water, Queensland, Australia Water Corporation of Western Australia, Perth Australia As a result of population growth, urbanization, and climate change, public water supplies are becoming stressed, and it is getting more difficult if not impossible to tap new water supplies for metropolitan areas. So, existing water supplies must go further. One way to do this is to increase water reuse, particularly in supplementing municipal water supplies by means of direct or indirect potable reuse. In the future, because it is inevitable that direct and/or indirect potable reuse will become part of the water management portfolio, it is critical that water and wastewater agencies begin to develop the necessary information and working relationships that will allow these potable reuse alternatives to become a reality. George Tchobanoglous, Ph.D. Professor emeritus, Department of Civil and Environmental Engineering, University of California, Davis. 11

12 Partnering for the future of water in Silicon Valley Now Open Stay involved At our purewater4u.org website, you can tap into a wealth of information about the facility and the state-of-the-art technologies being used to produce purified water from treated wastewater. You can sign up for a tour of the purification center, take a virtual tour and see news footage about Northern California s largest facility of its kind. CONTACT US For more information or to take a tour of the Silicon Valley Advanced Water Purification Center, contact Meenakshi Ganjoo at (408) , or visit our website at purewater4u.org. Follow us on: /scvwd /valleywater /valleywater To get enews, info@valleywater.org 12