Return to flip book view

The Future of Water is Here

Water reuse represents one of the most significant advances in water management since the Roman aqueducts. Around the world, communities are embracing water reuse as a proven solution for building climate-resilient water supplies. From California’s groundwater replenishment to Texas’s direct potable reuse, from Florida’s wetland systems to Arizona’s purple pipe networks, each region is writing its own water story. While this book draws primarily from U.S. examples, the concepts and solutions are relevant to communities everywhere facing water supply challenges.Through twenty-six concepts, from Aquifers to Zero Wasted Water, this book demystifies the science and engineering that make water reuse possible. These aren’t just definitions—they’re keys to understanding how innovation, technology, and nature work together to create robust and sustainable water resources. By making these concepts accessible to the public and providing clear language for ocials and local leaders, we hope to accelerate progress in water recycling across our communities.

Aquifers are nature’s underground water storage system. Think of them as Earth’s water savings account—we can deposit treated water here for future use! In places where these underground spaces have been overdrawn, purified recycled water is used to replenish them through a process called indirect potable reuse (IPR). This purified water, which is protected from evaporation and surface contamination, travels slowly through natural soils for months, gaining additional filtration before being treated again to rejoin our drinking water system. It’s a partnership between engineering and nature that’s helping secure our water future.Aquiferis for

Bottled Wateris forDespite its $10 billion industry status, bottled water’s success relies heavily on marketing that harms public confidence in tap water.Here’s the surprising truth: U.S. tap water often faces stricter oversight than bottled water, with the Environmental Protection Agency (EPA) and state regulators enforcing comprehensive quality standards. While bottled water is subject to less rigorous Food and Drug Administration (FDA) regulations, our tap water—including purified recycled water—undergoes extensive monitoring to ensure safety and quality.Today’s environmentally conscious consumers are recognizing this reality, trading disposable plastic bottles for reusable containers filled with high-quality tap water. It’s a shift that benefits both our environment and our wallets.

is forWhen evaluating water reuse investments, we must look beyond direct costs to see the bigger picture. While communities once relied on relatively inexpensive water sources, those days are fading. New water supplies often require massive infrastructure projects, like cross-state pipelines or coastal desalination plants, driving costs higher and higher.Cost &Community

In this context, potable reuse emerges as a practical investment. When compared to other alternative water supplies, purified recycled water often proves more cost-eective while providing something invaluable: reliability and resilience. Business leaders and economists increasingly recognize that a secure water supply is fundamental to a region’s economic vitality and quality of life. What’s the true value of water reuse? It’s best measured in thriving businesses, stable property values, and communities confident in their water supplies.

The practice of water reuse has undergone a remarkable transformation.While non-potable applications like irrigation remain important, advanced treatment technologies now enable us to purify recycled water to exceptionally high standards—fit for drinking.Through direct potable reuse, utilities can leverage existing drinking water infrastructure to distribute this high-quality water eciently and cost-eectively. This shift from irrigation-only to drinking water applications demonstrates both our technological capabilities and commitment to practical solutions. Unlike non-potable reuse that requires a separate dedicated piping network, direct potable reuse allows us to use the same pipes that deliver drinking water to your faucet today.By embracing direct potable reuse, communities can maximize existing infrastructure while providing reliable, sustainable water supplies for their residents.is forDrink It

The advanced treatment of recycled water sets remarkable standards of excellence. While all drinking water meets strict safety standards that protect public health, water reuse facilities add another dimension of treatment. Conventional drinking water treatment achieves 99.9% removal of protozoa and 99.99% removal of viruses—levels that provide safe, reliable drinking water. Advanced water purification builds on these standards, achieving 99.9999999999% removal of pathogenic organisms—matching or exceeding space-grade water treatment.This commitment to excellence extends to distribution. Modern water reuse programs are designed to deliver this highly purified water equitably throughout communities. It’s about providing everyone access to exceptional water quality while building upon the strong foundation of our current drinking water systems.is forExcellence & Equity

Excellence & Equity

The tides of public perception have turned. While bottled water companies once thrived on fears about tap water quality, today’s environmentally conscious consumers recognize the bigger picture. Reusable water bottles filled with local tap water have become a symbol of environmental awareness—a fashion statement that speaks to both sustainability and smart water choices. This shift reflects a deeper understanding that reliable water isn’t guaranteed and that supporting local water resources through everyday choices builds sustainable water independence.is forFashionable

Groundwateris forHidden beneath our feet lies an important water resource—not in puddles, but in vast underground reservoirs where water fills spaces between soil and rock. Many communities developed and thrived around these natural aquifers, but they face multiple challenges today. Over-pumping has led to depletion, industrial contamination has tainted some basins, and seawater intrusion threatens freshwater supplies when coastal aquifers are drawn down too far. Today, communities are turning to advanced water purification to revitalize these essential resources. Through indirect potable reuse, utilities purify recycled water to replenish groundwater basins.As this water slowly travels through natural soils—gaining additional purification along the way—it creates a sustainable cycle that transforms these troubled aquifers into reliable water supplies. It’s a remarkable turnaround story: basins that were once depleted or contaminated are now carefully managed, safe and reliable resources.

Groundwater

Protect public healthProtect public health

is forHealth ProtectionWhen it comes to recycled water, protecting public health isn’t just a priority—it’s an absolute requirement. That’s why potable reuse employs a multi-barrier treatment approach that surpasses conventional drinking water standards.Each stage of treatment serves as another layer of defense against contaminants. This approach eliminates viruses, bacteria, and chemical pollutants with unprecedented thoroughness. Public health agencies and water utilities continuously monitor these processes to see that every drop meets rigorous safety criteria.

is forIndirect Potable ReuseThrough indirect potable reuse (IPR), purified water takes the scenic route through natural systems. Unlike direct potable reuse, which sends purified recycled water straight to drinking water systems, IPR uses nature to assist with treatment. This can happen through groundwater recharge, aquifer injection, or release into lakes or rivers—with Mother Nature providing extra purification during its journey. Surface water augmentation with purified recycled water oers multiple benefits beyond drinking water supply. Released into lakes, rivers, and streams, this high-quality water supports recreation, creates wildlife habitat, and maintains environmental flows. It’s a perfect example of how water reuse can serve multiple purposes: protecting groundwater supplies, enhancing natural environments, and providing reliable drinking water for communities.

is forJobsWater reuse doesn’t just create water—it creates careers. Studies in Los Angeles show that every $1 million invested in water eciency projects generates approximately 16.6 job-years, outpacing both housing construction (11.3 job-years) and even the Hollywood film industry (8.3 job-years). One Los Angeles advanced water purificatin facility project alone is expected to create over 12,000 job-years through construction and operation.These aren’t just any jobs—they’re careers spanning engineering, science, construction, and community engagement. While builders and electricians construct the infrastructure, specialized operators and technicians maintain water quality, scientists optimize treatment methods, and outreach professionals build community trust. It’s a powerful example of how investing in water resilience strengthens both our infrastructure and our economy.

is forKnowledge SharingThe advancement of water reuse depends on shared expertise. By coming together to pool their knowledge, water utilities, private companies, universities, and community organizations are advancing the science and acceptance of purified recycled water. While engineers and operators share best practices about treatment technologies, researchers push innovation forward, and community educators build public understanding. This collaborative approach has transformed water reuse from an emerging concept into a proven solution. Through continuous learning and open dialogue among stakeholders, we’re not just sharing information—we’re building a stronger foundation for our future.

is forLog RemovalThink of log removal as water treatment’s report card—but instead of A through F, we’re counting nines.Each “log” represents a tenfold reduction in contaminants. A 4-log removal means 99.99% of contaminants are gone, leaving just 1 in 10,000. But today’s advanced water purification aims even higher, such as 12-log removal, or 99.9999999999%—that’s twelve nines! These impressive numbers aren’t just math; they’re how we measure safety in water reuse. Dierent treatment processes earn dierent “log removal credits,” and when combined, they create multiple barriers of protection. It’s like having several security checkpoints, each one making your water safer than the last.

is forMembranesMembrane technology revolutionized water treatment, marking a leap forward from the chemical treatments first used by ancient Egyptians and popularized in 19th-century America. The breakthrough came at UCLA, where researchers developed reverse osmosis (RO)—a process using semipermeable membranes with extremely tiny pores that act like selective doorways, primarily allowing water molecules to pass through while blocking most salts, organic matter, and many emerging contaminants. Many utilities are embracing the newest innovation—membrane bioreactors (MBR), which combine biological treatment with membrane filtration. This technology integration produces exceptional water quality while optimizing facility footprint and energy use. While RO is the cornerstone of some water reuse projects, alternative purification approaches without membranes are also viable. Along with other options like nanofiltration, ultrafiltration, and microfiltration, membranes are part of the multi-barrier toolkit used to design advanced water purification facilities.

is forBefore recycled water made its way to drinking water systems, it pioneered other important roles. From irrigating parks to cooling power plants, non-potable reuse oers smart solutions for water needs that don’t require drinking water quality. The applications are impressive: “Data Center Alley” in Virginia uses recycled water to cool facilities that process more than two-thirds of the world’s internet trac. In Detroit, General Motors captures and reuses stormwater for cooling towers at its assembly plant, saving $2 million annually. In Nevada, a planned 13-mile pipeline will deliver 1.3 billion gallons of recycled water yearly to the Tahoe-Reno Industrial Center, supporting tech giants like Tesla, Switch, and Google, and generating 20,000 new jobs.While such projects remain valuable for nearby users, the industry is increasingly focusing on potable reuse, which can use existing drinking water infrastructure and serve the broader community more cost-eectively. It’s a shift that shows how water reuse continues to evolve to meet our changing needsNon-Potable Reuse

Gone are the days of considering drinking water, wastewater, recycled water, and stormwater as separate challenges. The One Water approach recognizes that all water is connected—whether it’s flowing from our taps, captured from storms, or processed at treatment plants. This holistic vision is reshaping how major cities like New York, Denver, Los Angeles, and Honolulu plan their water future, breaking down silos between agencies and turning “waste” water into a valuable resource. By managing all water as one interconnected system, we reduce dependence on imported supplies, build climate resilience, and create a more sustainable future. It’s a philosophy that reminds us that every drop counts, every source matters, and every water investment should serve multiple purposes.is forOneWater

is forIn water reuse, success flows from collaboration. Historically, water and sanitation agencies operated in separate worlds—one focused on delivering drinking water, the other on treating wastewater. But potable reuse demands we break down these silos.Regional partnerships are now essential, with multiple utilities working together to optimize resources and share infrastructure. Water agencies partner with water resource recovery utilities to create new water supplies, while industrial facilities collaborate with municipal agencies to secure reliable water resources and ecient treatment solutions. These partnerships often cross jurisdictional boundaries, creating networks of shared expertise and infrastructure.These collaborations extend beyond agency boundaries to include regulators, community groups, and technical experts—all working together to build public trust and create a more resilient water future.Water knows no boundaries, so neither should our eorts to manage it wisely.Partnerships

is forQualityAll drinking water facilities operate under extensive oversight to meet rigorous quality standards that protect public health. Advanced water purification facilities must meet these high standards, along with additional monitoring, testing, and documentation requirements specific to water reuse.Non-potable recycled water systems also maintain high-quality standards appropriate for their specific uses, from irrigation to industrial applications. Each type of reuse has clear quality criteria, testing protocols, and operational requirements that facilities must meet consistently.This commitment to water quality involves continuous monitoring, frequent testing, and thorough documentationThrough these practices, recycled water—whether for drinking water or other purposes—meets or exceeds all regulatory standards for its intended use.

is forRegulations are the foundation of safe and successful water reuse programs, establishing clear standards for public health and environmental protection. While the EPA regulates drinking water and wastewater treatment, there are no federal regulations governing water recycling or potable reuse. This means each state has had to develop its own regulatory approach. Through extensive collaborations between many stakeholder groups and leadership from states such as Florida, California, Texas, Arizona, and Colorado, regulatory precedents for reuse are now widely available. All regulations specify treatment requirements, establish monitoring protocols, and define water quality standards for various water recycling applications.As more states adopt and enhance their water reuse regulations, they are taking steps to protect public health and help communities develop safe, sustainable water supplies.Regulations

is forSustainabilityA sustainable water future isn’t just about conserving what we have—it’s about reimagining how we use every drop.Water reuse transforms our traditional linear system (use once and dispose) into a circular system where water can be used again and again. This circular approach is especially crucial in regions where droughts and population growth challenge our water security. By treating and reusing water locally, we reduce dependence on imported supplies and the need for new water sources, lower our environmental impact, and create a more resilient system for future generations.

From your kitchen sink to your morning shower, tap water is the gold standard for water quality. As traditional water sources become increasingly stressed, utilities and communities are turning to new solutions to maintain this essential service.While traditional tap water often comes from local groundwater or surface water, advanced water purification facilities are creating a new source that’s just as pure. Through a combination of advanced purification processes like microfiltration, reverse osmosis, ultraviolet disinfection, ozone, biofiltration, and/or granular activated carbon, recycled water is purified to match the quality of conventional tap water. It’s a transformation that proves the future of water can flow right from our taps, whether it started as snowmelt or is locally purified through advanced treatment.is forTap Water

While water may seem plentiful in some regions, traditional local sources are increasingly stretched to their limits. Communities seeking “new water” must often look farther and farther away, increasing both costs and environmental impacts.Sometimes, seemingly obvious solutions are not practical or cost-eective. Seawater desalination, for example, requires massive energy input—about four times more than water recycling—poses significant environmental challenges, and is only available in coastal regions.By using our local water resources wisely and reusing them as often as possible, we can create sustainable solutions that work for any region. Whether driven by population growth, environmental needs, economic development, or changing climate patterns, communities are discovering that water reuse is the smart choice for their future.is forUsing Local WaterWisely

While rain may fall freely from the sky, delivering safe, reliable water to your tap is another story.When evaluating recycled water projects, we shouldn’t compare their costs to our existing water supplies. Instead, we should compare them to the cost of the next-best option to provide water to our growing communities. And beyond just comparing dollars, we should consider the true value of water security—what would it cost our communities to run out of water?When we invest in water reuse, we’re not just paying for water—we’re investing in infrastructure that ensures a reliable, drought-proof supply for generations to come. It’s a reminder that while recycled water projects can come at a substantial cost, water reliability is priceless.is forValue

Yesterday’s wastewater is tomorrow’s water supply. What flows down our drains— from homes, businesses, and industries—isn’t waste at all, but rather a reliable local water source waiting to be tapped.Through advanced water purification facilities, this water can be purified to exceptional standards, creating a new supply while reducing discharge to sensitive water bodies. As environmental regulations become more stringent, utilities are recognizing a dual opportunity: by treating water to higher standards, they can both protect the environment and create a valuable new water resource.It’s the circular water economy in action: transforming what we once considered waste into an asset. By closing the urban water loop, we’re not just conserving water—we’re revolutionizing how we think about water use while reducing our environmental impact.is forWastewater

Think of xenobiotics as uninvited guests in our water supply—synthetic chemicals from pharmaceuticals, personal care products, and ndustrial processes that don’t naturally belong there.Unlike many natural contaminants, some stubborn xenobiotics can resist conventional treatment methods. That’s why advanced water purification facilities employ a powerful combination of defenders: physical separation, chemical oxidation, biological degradation, UV light photolysis, and adsorption. This multi-barrier approach ensures that these synthetic chemicals are removed before water is reused. It’s part of our commitment to producing water that’s not just clean but purified for all possible contaminants, whether natural or human-made. is forXenobiotics

More and more communities are saying “yes” to water reuse as a local solution to water security. While the idea of recycling water may have once seemed novel, today it represents a smart approach to sustainable water management.It’s a powerful shift in thinking: instead of depending solely on traditional water sources, communities are creating reliable supplies right in their own neighborhoods.This approach demonstrates that some of our best water solutions can be found close to home.is forYES

Zero wasted water means exactly what it sounds like—nothing goes to waste. It’s about creating systems where every drop of water is continuously recycled and reused to its fullest potential. Many facilities are already achieving this goal through approaches tailored to local needs. Water recovery facilities implement advanced treatment processes for complete water recycling. This concept extends beyond utilities to universities that recirculate cooling water, food manufacturers that reuse process water, and research facilities that recycle water for testing and training. The path to zero wasted water depends on local water quality, regulations, and intended use. Communities and industries are finding innovative ways to maximize recycling and reuse, balancing water recovery with energy use and costs. It’s the perfect example of how water reuse is changing our perspective: what was once considered disposable is now viewed as a resource too valuable to throw away..is forZero Wasted Water