WASHINGTON – New data released by the Environmental Protection Agency shows an additional 6.5 million Americans have drinking water contaminated by the toxic “forever chemicals” known as PFAS. It brings the total number of people at risk of drinking this contaminated tap water to about 165 million across the U.S.
“It is impossible to ignore the growing public health crisis of PFAS exposure. It’s detectable in nearly everyone and it’s found nearly everywhere, including the drinking water for a huge segment of the population,” saidDavid Andrews, Ph.D., acting chief science officer at the Environmental Working Group.
“The documented extent of PFAS contamination of the country’s water supply highlights the enormous scale of contamination,” he added.
The EPA’s new findings come from tests of the nation’s drinking water supply conducted as part of the Fifth Unregulated Contaminant Monitoring Rule, or UCMR 5, which requires U.S. water utilities to test drinking water for 29 individual PFAS compounds.
The EPA has said it will roll back limits on four PFAS in drinking water, leaving those chemicals unregulated. It plans to only retain standards for the two most notorious chemicals, PFOA and PFOS. These maximum contaminant levels or MCLs, set enforceable standards for the amount of contaminants allowed in drinking water.
Even with keeping the PFOA and PFOS MCLs in place, rolling back the four other limits will make it harder to hold polluters responsible and ensure clean drinking water.
In addition, the EPA’s plan to reverse the four science-based MCLs likely contradicts an anti-backsliding provision in the Safe Drinking Water Act. That law requires any revision to a federal drinking water standard “maintain, or provide for greater, protection of the health of persons.”
“It’s worrying to see the EPA renege on its commitments to making America cleaner and safer, especially as it ignores its own guidelines to do so,” said Melanie Benesh, EWG’s vice president for government affairs.
Widespread PFAS pollution
The Trump administration’s PFAS standards rollback could grant polluters unchecked freedom to release toxic forever chemicals into U.S. waterways, endangering millions of Americans.
EWG estimates nearly 30,000 industrial polluters could be discharging PFAS into the environment, including into sources of drinking water. Restrictions on industrial discharges would lower the amount of PFAS ending up in drinking water sources.
“Addressing the problem means going to the source. For PFAS, that’s industrial sites, chemical plants and the unnecessary use of these chemicals in consumer products,” said Andrews.
Health risks of PFAS exposure
PFAS are toxic at extremely low levels. They are known as forever chemicals because once released into the environment, they do not break down and can build up in the body. The Centers for Disease Control and Prevention has detected PFAS in the blood of 99 percent of Americans, including newborn babies.
For over 30 years, EWG has been dedicated to safeguarding families from harmful environmental exposures, holding polluters accountable and advocating for clean, safe water.
“Clean water should be the baseline,” Andrews said, “The burden shouldn’t fall on consumers to make their water PFAS-free. While there are water filters that can help, making water safer begins with ending the unnecessary use of PFAS and holding polluters accountable for cleanup.”
For people who know of or suspect the presence of PFAS in their tap water, a home filtration system is the most efficient way to reduce exposure. Reverse osmosis and activated carbon water filters can be extremely effective at removing PFAS.
EWG researchers tested the performance of 10 popular water filters to evaluate how well each reduced PFAS levels detected in home tap water.
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The Environmental Working Group is a nonprofit, non-partisan organization that empowers people to live healthier lives in a healthier environment. Through research, advocacy and unique education tools, EWG drives consumer choice and civic action.
PFAS, also known as “forever chemicals,” have emerged as a serious environmental and public health threat due to their persistence and widespread contamination. These man-made chemicals, widely utilized in consumer and industrial products since World War II, are now linked to alarming levels of contamination in drinking water supplies and health risks ranging from cancers to liver toxicity to reduced fertility.
Following decades of litigation, the U.S. Environmental Protection Agency in 2024 finally set legally enforceable levels for six PFAS chemicals in drinking water, requiring public water systems to monitor for the substances, report findings to customers, and take steps to reduce contamination. However, those regulations were partially rolled back in May 2025.
In this Q&A, two Yale experts delve into the challenges posed by PFAS and potential solutions for reducing exposure and contamination. Vasilis Vasiliou is Department Chair and Susan Dwight Bliss Professor of Epidemiology at Yale School of Public Health (YSPH). Robert Bilott is an environmental attorney and serves as a lecturer with the YSPH Department of Environmental Health Sciences. Bilott’s story and landmark case against chemical giant DuPont were recounted in his book, “Exposure: Poisoned Water, Corporate Greed, and One Lawyer’s Twenty-Year Battle Against DuPont,” and were the basis for the 2019 motion picture “Dark Waters,” starring Mark Ruffalo.
This interview was edited and condensed for clarity.
What are PFAS?
BILOTT: PFAS stands for per- and polyfluoroalkyl substances. They are a completely man-made family of chemicals created around the time of World War II. These chemicals, formed by artificially connecting carbon and fluorine, are known for their strength, stain resistance, grease protection, and water resistance. They are used in a wide variety of products, and there are now estimates of up to 14,000 different PFAS compounds.
Why are PFAS called ‘forever chemicals?’
VASILIOU: PFAS are often called ‘forever chemicals’ because they contain an exceptionally strong carbon-fluorine bond, which makes them highly resistant to breakdown. As a result, they persist in the environment for decades or longer—in water, soil, and even living organisms. Their environmental and biological persistence means they can accumulate over time, raising long-term concerns for ecosystems and public health.
What consumer or industrial products contain PFAS?
BILOTT: PFAS have been used in an incredible array of consumer and commercial products since the 1940s. Common products containing PFAS include non-stick cookware, carpeting, clothing, fast food wrappers and packaging, computer chips, toilet paper, and waterproof cosmetics. Keywords like stain-resistant, waterproof, grease-resistant, and non-stick often indicate the presence of PFAS. These chemicals were not listed on ingredient lists or labels, and many companies were unaware they were using them.
What are the known health risks associated with PFAS?
VASILIOU: PFAS are linked to various cancers such as kidney, testicular, and liver cancer, as well as liver toxicity. There is a rising incidence of early-onset cancers, like colon and liver cancer, in younger individuals, potentially due to developmental exposure. Developmental and reproductive effects of PFAS include low birth weight, accelerated puberty, reduced fertility, and pregnancy-induced hypertension, with possible epigenetic changes that might contribute to early-onset cancers. PFAS also impair the immune system, reducing vaccine effectiveness and potentially increasing susceptibility to infections like COVID-19. Additionally, PFAS exposure is linked to various metabolic effects such as obesity, type 2 diabetes, cardiovascular disease, reduced kidney function, high cholesterol, colitis, and neurodegenerative issues in children.
By some estimates, 90% of drinking water in the U.S. contains PFAS. How did that happen?
BILOTT: PFAS contamination in drinking water primarily comes from aqueous film-forming foam, or AFFF—the firefighting foam that was developed during the Vietnam War to extinguish petroleum-based fires. This foam contains high concentrations of C-8 PFAS chemicals known as PFOA and PFOS that have been widely used by military organizations, airports, and fire stations globally since the 1960s. The people buying and using it were not informed about its PFAS content and were misled about its safety, which led to widespread environmental contamination.
Has a safe level for PFAS chemicals been identified?
BILOTT: No one has identified a safe level of PFAS chemicals. Companies like 3M and DuPont set internal safety guidelines for their employees decades ago, but this information was withheld from government agencies and scientists until much later. Studies have revealed that PFAS are persistent, bioaccumulative, and toxic, affecting multiple organ systems and potentially reducing vaccine effectiveness. The EPA has set very low drinking water standards, aiming for no more than four parts per trillion and ideally zero for PFOA and PFOS, which are now recognized as human carcinogens.
VASILIOU: PFAS chemicals are not metabolized by the body, unlike many other environmental contaminants. Because they resist breakdown and are only slowly excreted, they accumulate in human tissues—especially in the blood, liver, and kidneys—over time. This bioaccumulation contributes to a range of toxic effects, including immunotoxicity, endocrine disruption, and increased risk of kidney and testicular cancer. Given their extreme persistence and potential for harm even at very low levels, efforts to establish safe exposure limits increasingly aim toward zero.
Can the human body repair damage caused by PFAS?
VASILIOU: The human body has some ability to repair tissue damage, but with PFAS, this process is complicated by the chemicals’ persistence. PFAS remain in the body for years and can interfere with normal repair mechanisms by promoting inflammation, oxidative stress, and immune dysfunction. Even if some tissues, like the liver, can regenerate, ongoing internal exposure means that damage may continue, making full recovery difficult—especially with chronic or high-level exposures.
Are any PFAS chemicals regulated?
BILOTT: In 2024, the first federal nationwide regulations for PFAS chemicals were adopted by the EPA, setting drinking water standards and declaring two C-8 PFAS as hazardous under federal Superfund law. The process took decades, with companies pushing back and fighting regulation in courts. States like New Jersey, Minnesota, and Connecticut have also moved forward with regulations, which are facing legal challenges from manufacturers. In Europe, proposed global bans on PFAS face significant opposition due to economic impacts.
What technologies exist to remove PFAS from drinking water?
VASILIOU: Activated carbon and reverse osmosis are the primary technologies to remove PFAS, though reverse osmosis is very expensive for individual homes. Yale engineers are working on innovative solutions, such as membranes and methods to break down PFAS chemicals.
Who is going to pay for cleaning up PFAS contamination?
BILOTT: Our law firm represents hundreds of cities seeking compensation from companies like 3M and DuPont, who created the chemicals. These cases are part of the aqueous film-forming foam (AFFF) multidistrict litigation in South Carolina. Recently, significant settlements totaling over $14 billion from companies like 3M, DuPont, BASF, and Tyco have been reached to help public water systems clean up PFAS. The federal government has allocated $10 billion for this purpose but that is taxpayer money. We are working to ensure the responsible companies pay for the cleanup.
How does someone know if PFAS is present in their drinking water or consumer products?
BILOTT: It’s not always easy. For public water systems, sampling is starting to be required and information may be available in quarterly reports to customers. But many districts haven’t started testing yet. The Environmental Working Group created an interactive map showing where testing has occurred and what the levels are. For consumer products, there’s a lot less information. PFAS were not listed on ingredient labels or material safety data sheets, and even manufacturers might not have known they were using PFAS. Some groups are now testing products for PFAS, and products labeled with buzzwords like waterproof, stain-resistant, non-stick, and grease-proof might contain PFAS. Consumer demand has led some companies to commit to PFAS-free products, but definitions and detection levels vary so that is causing mass confusion in the market.
What can the average person do about the PFAS problem?
VASILIOU: Individuals can reduce their PFAS exposure by avoiding products such as older non-stick cookware, water-resistant clothing, stain-proof textiles, and certain cosmetics that may contain PFAS. It’s also important to be informed about your drinking water—use certified filters that are effective against PFAS and consult local or state resources for water quality information, including bottled water when available. Beyond personal choices, civic engagement plays a powerful role. Raising awareness, supporting legislation, and demanding transparency from manufacturers and regulators can drive meaningful, large-scale change
BILOTT: An individual can make a huge difference by standing up, speaking out, and demanding change. It may take a while, but as you see in the story of “Dark Waters,” individuals speaking out are having a huge impact. Laws are being proposed and passed to restrict these chemicals. Some of the biggest companies on the planet are now committing to getting out of PFAS. That only happened by individuals saying ‘we don’t want this.’
What is Yale doing?
Yale is committed to making the university a healthy and productive place to live, work, and study. We are reducing the amount of harmful chemicals on campus through healthy furniture standards to reduce the amount of chemicals of concern in the materials we purchase to furnish our buildings. The Yale School of Public Health is leading groundbreaking research into the human health impacts of PFAS, analyzing their role in cancer cell migration, liver damage, and pregnancy loss. The Yale School of Engineering and Applied Sciences is developing technologies to separate and destroy PFAS at water treatment facilities and other locations.
WASHINGTON – U.S. Environmental Protection Agency (EPA) Administrator Lee Zeldin announced the agency will keep the current National Primary Drinking Water Regulations (NPDWR) for perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS), which set nationwide limits for these “forever chemicals” in drinking water. The agency is committed to addressing Per- and Polyfluoroalkyl substances (PFAS) in drinking water while following the law and ensuring that regulatory compliance is achievable for drinking water systems.
“The work to protect Americans from PFAS in drinking water started under the first Trump Administration and will continue under my leadership,” saidEPA Administrator Zeldin. “We are on a path to uphold the agency’s nationwide standards to protect Americans from PFOA and PFOS in their water. At the same time, we will work to provide common-sense flexibility in the form of additional time for compliance. This will support water systems across the country, including small systems in rural communities, as they work to address these contaminants. EPA will also continue to use its regulatory and enforcement tools to hold polluters accountable.”
As part of this action, EPA is announcing its intent to extend compliance deadlines for PFOA and PFOS, establish a federal exemption framework, and initiate enhanced outreach to water systems, especially in rural and small communities, through EPA’s new PFAS OUTreach Initiative (PFAS OUT). This action would help address the most significant compliance challenges EPA has heard from public water systems, members of Congress, and other stakeholders, while supporting actions to protect the American people from certain PFAS in drinking water.
Paired with effluent limitations guidelines (ELGs) for PFAS and other tools to ensure that polluters are held responsible, EPA’s actions are designed to reduce the burden on drinking water systems and the cost of water bills, all while continuing to protect public health and ensure that the agency is following the law in establishing impactful regulations such as these.
EPA is also announcing its intent to rescind the regulations and reconsider the regulatory determinations for PFHxS, PFNA, HFPO-DA (commonly known as GenX), and the Hazard Index mixture of these three plus PFBS to ensure that the determinations and any resulting drinking water regulation follow the legal process laid out in the Safe Drinking Water Act.
Regulatory Protection with Flexibility and Cost Savings
On April 10, 2024, EPA announced the final National Primary Drinking Water Regulation, including standards for PFOA and PFOS. At that time, EPA established legally enforceable levels for these PFAS in drinking water and gave public water systems until 2029 to comply with the Maximum Contaminant Levels (MCLs).
To allow drinking water systems more time to develop plans for addressing PFOA and PFOS where they are found and implement solutions, EPA plans to develop a rulemaking to provide additional time for compliance, including a proposal to extend the compliance date to 2031. EPA plans to issue a proposed rule this fall and finalize this rule in the Spring of 2026. Aligned with the agency’s intent to provide additional compliance time for water systems, EPA encourages states seeking primacy for implementing the PFAS drinking water regulation to request additional time from EPA to develop their applications. At the same time, EPA will support the U.S. Department of Justice in defending ongoing legal challenges to the PFAS National Primary Drinking Water Regulation with respect to PFOA and PFOS.
“EPA has done the right thing for rural and small communities by delaying implementation of the PFAS rule. This commonsense decision provides the additional time that water system managers need to identify affordable treatment technologies and make sure they are on a sustainable path to compliance. NRWA greatly appreciates this reasonable and flexible approach, and we look forward to partnering with the agency’s PFAS OUTreach Initiative to help ensure water systems have the resources and support they need,” said National Rural Water Association CEO Matthew Holmes.
“ASDWA supports EPA’s proposed approach to the PFAS regulation to extend the compliance date for systems by an additional two years. With the current compliance date of 2029, states and water systems are struggling with the timeframes to complete the pilot testing, development of construction plans, and building the necessary treatment improvements. EPA’s proposed extension of the compliance date and increased technical assistance will address the number of systems that would be out of compliance in 2029 due to not being able complete all of these tasks on time,” said Association of State Drinking Water Administrators Executive Director Alan Roberson.
Enhancing Communication and Outreach
To enhance engagement on addressing PFAS, EPA will launch PFAS OUT to connect with every public water utility known to need capital improvements to address PFAS in their systems, including those EPA has identified as having PFOA and PFOS levels above EPA’s MCL. EPA will share resources, tools, funding, and technical assistance to help utilities meet the federal drinking water standards. PFAS OUT will ensure that no community is left behind as we work to protect public health and bring utilities into compliance with federal drinking water standards. PFAS OUT will engage utilities, technical assistance providers and local, State, Tribal, and Territorial leaders to develop effective, practical solutions where they are needed most.
EPA will continue to offer free water technical assistance (WaterTA) that provides services to water systems to improve their drinking water and help communities access available funding. EPA’s WaterTA initiatives work with water systems nationwide to identify affordable solutions to assess and address PFAS, including PFOA and PFOS. Services offered to utilities include water quality testing, development of technical plans, operator training support, designing public engagement and outreach strategies, and support for accessing federal funding opportunities.
Holding Polluters Accountable
Drinking water systems are passive receivers of PFOA and PFOS. Polluters can contaminate the surface waters or aquifers that these systems rely on to provide the drinking water to their communities. As announced by Administrator Zeldin, EPA intends to take a number of actions to reduce the prevalence of PFAS in the environment, including in sources of drinking water. Progress reducing concentrations of PFAS in drinking water sources can substantially reduce the cost burden for water systems and reduce the cost of living for the communities they serve.
A Record of Leadership
Administrator Zeldin’s leadership on PFAS dates back to his time in Congress, where he was a founding member of the PFAS Congressional Taskforce and a strong supporter of the PFAS Action Act, legislation to provide funding to support local communities cleaning up PFAS-contaminated water systems. He was, and remains, a staunch advocate for protecting Long Islanders and all Americans from contaminated drinking water.
In the process of developing and taking action on a number of these items, Administrator Zeldin personally heard from members of Congress on passive receiver issues where local water utilities will foot the bill for contamination and pass those costs onto consumers. This mindset and the need for a polluter pays model has guided a lot of the work to be done at EPA in the future.
Background
On April 28, 2025, Administrator Zeldin announced a long list of actions to combat PFAS contamination that included in part the designation of an agency lead for PFAS, the development of ELGs for certain PFAS to reduce discharges to waterways including upstream of drinking water systems, and initiatives to engage with Congress and industry to establish a clear liability framework that ensures passive receivers and consumers are protected. This list is the first, not the last, of all decisions and actions EPA will be taking to address PFAS over the course of the Trump Administration. There will be more to come in the future across EPA’s program offices to help communities impacted by PFAS contamination.
During President Trump’s first term, EPA convened a two-day National Leadership Summit on PFAS in Washington, D.C. that brought together more than 200 federal, state, and local leaders from across the country to discuss steps to address PFAS. Following the Summit, the agency hosted a series of visits during the summer of 2018 in communities directly impacted by PFAS. EPA interacted with more than 1,000 Americans during community engagement events in Exeter, New Hampshire, Horsham, Pennsylvania, Colorado Springs, Colorado, Fayetteville, North Carolina, and Leavenworth, Kansas, as well as through a roundtable in Kalamazoo, Michigan, and events with tribal representatives in Spokane, Washington.
In 2019, the Trump EPA announced the PFAS Action Plan. This historic Plan responded to extensive public interest and input the agency received and represented the first time EPA built a multi-media, multi-program, national communication and research plan to address an emerging environmental challenge like PFAS. EPA’s Action Plan identified both short-term solutions for addressing these chemicals and long-term strategies that will help provide the tools and technologies states, tribes, and local communities need to provide clean and safe drinking water to their residents and to address PFAS at the source—even before it gets into the water.
EPA supports water systems in reducing PFAS and emerging contaminants (EC) in drinking water through a range of funding resources. Federal funding opportunities include the Drinking Water State Revolving Fund (DWSRF) program, the EC Small or Disadvantaged Communities (EC-SDC) grant program, and funding resources, like EPA’s Water Infrastructure Finance and Innovation Act (WIFIA) program, that can be leveraged to provide supplemental, flexible, low-cost credit assistance to public and private borrowers.
From fluoride to “forever chemicals,” drinking water has been in the spotlight this year. In a Q&A, Yale epidemiologist Nicole Deziel discusses the water we drink today — and what’s on tap for the future.
Aug 13, 2025
7 min read
By Meg Dalton
(Illustration by Michael S. Helfenbein)
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In 1945, Grand Rapids, Michigan, made history — as the first city in the world to add small amounts of fluoride to its public water supply. At the time, studies showed communities with higher levels of natural fluoride in water had better dental health. Water fluoridation is now practiced in about 25 countries around the world, including Spain, Malaysia, and the United States. In the U.S., approximately 63% of the population drinks fluoridated water.
Low levels of fluoride, a naturally occurring mineral, can be found in many sources of drinking water due to natural processes like the weathering of rocks and human activities like manufacturing. However, there’s growing debate over whether additional fluoride should be introduced to drinking water. This year, states including Utah and Florida have banned the use of fluoride in public water systems, and federal officials have called for more states to follow suit.
Nicole Deziel is an associate professor of epidemiology (environmental health sciences) and co-director of the Yale Center for Perinatal, Pediatric and Environmental Epidemiology at the Yale School of Public Health. In an interview, she explains the benefits and risks of fluoride, how “forever chemicals” and climate change impact water quality, and how we can monitor the water we drink.
Nicole Deziel
The interview has been edited for length and clarity.
What are the benefits of fluoride? Are there any potential risks?
Nicole Deziel: Fluoride can strengthen our bones and teeth enamel, and the strengthening of the enamel prevents cavities. But too much of it can damage our bones and enamel in a process called fluorosis, and it can potentially have neurological effects as well. Fluoridation of the public water supply can help address disparities in dental insurance and access to dental care.
Finding the right amount where the benefits outweigh the risks is key. The U.S. Public Health Service recommends a fluoride concentration of 0.7 mg/L [parts per million] in drinking water. The World Health Organization recommends a limit of 1.5 mg/L, while the U.S. Environmental Protection Agency sets a limit of 4 mg/L. Newer evidence of more subtle neurological effects is prompting reexamination of these target levels and limits.
Why are we seeing some states ban the use of fluoride in public water systems? Why are some people suspicious of it?
Deziel: There’s a long history of controversy about fluoride, including urban legends and conspiracy theories. For some people, it may seem counterintuitive to add a chemical that may have some toxic properties to make our water safer. However, we do this with chlorine as well. Chlorine is toxic at high levels and can form harmful byproducts, but we add it to drinking water to disinfect it and kill bacteria and pathogens to make our water safe to drink. We’re often doing these kinds of tradeoffs in environmental health and public health. In addition, misinformation and distrust of science could all be contributing to us revisiting this [the fluoridation of water].
Finding the right amount [of fluoride] where the benefits outweigh the risks is key.
Nicole Deziel
However, there’s been some new data that should prompt us to reexamine fluoride. There have been a few recent studies that have shown that fluoride exposure is linked to lower IQ levels in children where fluoride levels are above some of the target levels. Some in the dental community have raised concerns about how the data in those studies are being interpreted. Given these concerns, it is important that experts across disciplines collectively re-examine the latest evidence on fluoride’s risks and benefits to ensure the public and policymakers receive clear, evidence-based guidance.
Let’s move from fluoride to so-called “forever chemicals,” also known as PFAS. What are PFAS, and why are they called “forever chemicals”?
Deziel: PFAS, or per- and polyfluoroalkyl substances, are commonly referred to as “forever chemicals” due to their persistence in the environment as well as human bodies. They’re molecules that have chains of carbon and fluorine, and the carbon-fluorine bond is the strongest chemical bond known.
Their properties have made PFAS very desirable in many consumer products like Teflon pans, stain-resistant and water-resistant clothing and textiles, food packaging, and more. They’re also in firefighting foam.
According to some estimates, 90% of drinking water in the U.S. contains PFAS. How did happen, and what impact do PFAS have on our health?
Deziel: This happens for a few reasons, such as improper disposal of PFAS at manufacturing sites and the use of firefighting foams at airports and military bases. But PFAS are also in household products, many of which can go down the drain and be introduced into our environment.
PFAS have been linked to a variety of adverse health problems, including endocrine disruption, cancer, reproductive effects, decreased effects on our immune system, decreased efficacy of vaccines, and more.
Last year, the U.S. set the first-ever national limits on PFAS. Now, some of those regulations are being delayed or reconsidered. How are limits set for contaminants like PFAS?
Deziel: The Environmental Protection Agency sets maximum contaminant levels for drinking water under the Safe Drinking Water Act. When they set them, they’re allowed to consider not just public health but technological or economic feasibility. It took about 20 years just to get the PFAS standards passed, even though we’ve known about these issues for decades. This is a very slow and inefficient process, and the standards are not keeping pace with the science. So, it’s frustrating that the few new standards set may not even move forward.
In recent years, we’ve also seen several extreme weather events, from wildfires and floods to intense heat and droughts. How does climate change threaten the safety of our drinking water?
Deziel: Climate change can impact our drinking water in many ways. First, increasing intense droughts can affect our water supplies and lead to water scarcity. With wildfires, we often focus on the smoke and the immediate damage, but once the fires have been addressed, there are concerns about all the fire-retardant chemicals that are deposited into our soils and waterways. Plus, wildfires require a lot of water. Rising sea levels can create saltwater intrusion into freshwater sources. Floods and storms can release chemicals into our waterways and impact our water infrastructure overall. So there are many ways our changing climate and extreme weather can affect drinking water.
What can people like you and me do to monitor — and even improve — the quality of the water we drink?
Deziel: In public health, we talk about a hierarchy of controls. So, the best would be to have evidence-based drinking water standards that reflect the best science, and that would be because not everybody has the time and resources to research different strategies or purchase different filters.
However, if someone wanted to reduce their exposures to chemicals, there are several different filtering devices that are available. The most common is the charcoal, or activated carbon, filter. These can remove some chemicals including chlorine, some metals, some organic contaminants, and some but not all PFAS. They can be installed for the whole house, under the sink, or directly on the faucet. Reverse osmosis filters, which push water through a special membrane, are more effective at removing a much wider range of chemicals, but they’re more expensive. Countertop and pitcher-style filters are other options. They use gravity to pass water through a carbon cartridge. They’re generally more affordable, and while they don’t remove as many contaminants as in-line systems, they offer some protection and may be a good starting point for some households.
People may be tempted to turn to bottled water. However, many brands of bottled water are just tap water that’s been run through extra purification steps (spring water and mineral water are exceptions). This additional treatment can mean the water is very clean, but bottled water comes with significant downsides. In the U.S., only a tiny fraction of the millions of plastic bottles we use actually get recycled, with most polluting streets, rivers, and oceans. Producing those bottles uses petroleum and releases greenhouse gases, adding to climate change. Moreover, single-use plastic bottles can release endocrine-disrupting chemicals called phthalates as well as tiny plastic particles known as microplastics, especially if left in sunlight and heat.
Water is life. Yet, as the world population mushrooms and climate change intensifies droughts, over 2 billion people still lack access to clean, safe drinking water. By 2030, water scarcity could displace over 700 million people. From deadly diseases to famines, economic collapse to terrorism, the global water crisis threatens to sever the strands holding communities together. This ubiquitous yet unequally distributed resource underscores the precarious interdependence binding all nations and ecosystems and shows the urgent need for bold collective action to promote global water security and avert the humanitarian, health, economic, and political catastrophes that unchecked water stress promises.
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The global water crisis refers to the scarcity of usable and accessible water resources across the world. Currently, nearly 703 million people lack access to water – approximately 1 in 10 people on the planet – and over 2 billion do not have safe drinking water services. The United Nations predicts that by 2025, 1.8 billion people will be living in countries or regions with absolute water scarcity. With the existing climate change scenario, almost half the world’s population will be living in areas of high water stress by 2030. In addition, water scarcity in some arid and semi-arid places will displace between 24 million and 700 million people. By 2030, water scarcity could displace over 700 million people.
In Africa alone, as many as 25 African countries are expected to suffer from a greater combination of increased water scarcity and water stress by 2025. Sub-Saharan regions are experiencing the worst of the crisis, with only 22-34% of populations in at least eight sub-Saharan countries having access to safe water.
Water security, or reliable access to adequate quantities of acceptable quality water for health, livelihoods, ecosystems, and production has become an urgent issue worldwide.
This crisis has far-reaching implications for global health, food security, education, economics, and politics. As water resources dwindle, conflicts and humanitarian issues over access to clean water will likely increase. Climate change also exacerbates water scarcity in many parts of the world. Addressing this complex and multifaceted crisis requires understanding its causes, impacts, and potential solutions across countries and communities.
The global water crisis stems from a confluence of factors, including growing populations, increased water consumption, poor resource management, climate change, pollution, and lack of access due to poverty and inequality.
The world population has tripled over the last 70 years, leading to greater demand for finite freshwater resources. Agricultural, industrial, and domestic water usage have depleted groundwater in many regions faster than it can be replenished. Agriculture alone accounts for nearly 70% of global water withdrawals, often utilizing outdated irrigation systems and water-intensive crops.Climate change has significantly reduced renewable water resources in many parts of the world. Glaciers are melting, rainfall patterns have shifted, droughts and floods have intensified, and temperatures are on the rise, further exacerbating the crisis.
Baseline water stress measures the ratio of total water withdrawals to available renewable water supplies. Image: United Nations (2019).
In many less developed nations, lack of infrastructure, corruption, and inequality leave large populations without reliable access to clean water. Women and children often bear the burden of travelling distances to fetch water for households. Contamination from human waste, industrial activities, and agricultural runoff also threaten water quality and safety.
Water scarcity poses risks to health, sanitation, food production, energy generation, economic growth, and political stability worldwide. Conflicts over shared water resources are likely to intensify without concerted global action.
Case Study: Water Crisis in Gaza
The water crisis in Gaza represents one of the most severe cases of water scarcity worldwide. The small Palestinian territory relies almost entirely on the underlying coastal aquifer as its source of freshwater. However, years of excessive pumping far exceed natural recharge rates. According to the UN, 97% groundwater does not meet World Health Organization (WHO) standards for human consumption due to high salinity and nitrate levels.
The pollution of Gaza’s sole freshwater source stems from multiple factors. Rapid population growth contaminated agricultural runoff, inadequate wastewater treatment, and saltwater intrusion due to over-extraction have rendered the aquifer unusable.
In June 2007, following the military takeover of Gaza by Hamas, the Israeli authorities significantly intensified existing movement restrictions, virtually isolating the Gaza Strip from the rest of the occupied Palestinian territory (oPt), and the world. The blockade imposed by Israeli Authority also severely restricts infrastructure development and humanitarian aid.
The water crisis has devastated Gazan agriculture, caused widespread health issues, and crippled economic growth. Many citizens of Gaza have to buy trucked water of dubious quality, as the public network is unsafe and scarce. The United Nations Relief and Works Agency for Palestine Refugees in the Near East (UNRWA) reports that this water can cost up to 20 times more than the public tariff, with some households spending a third of their income or more on water. Long-term solutions require increased water supplies, wastewater reuse, desalination, and better resource management under conflict.
According to a 2022 report by the WHO and UNICEF’s Joint Monitoring Programme (JMP), 344 million people in sub-Saharan Africa lacked access to safely managed drinking water, and 762 million lacked access to basic sanitation in 2020. WaterAid, a non-governmental organization, explains that water resources are often far from communities due to the expansive nature of the continent, though other factors such as climate change, population growth, poor governance, and lack of infrastructure also play a role. Surface waters such as lakes and rivers evaporate rapidly in the arid and semi-arid regions of Africa, which cover about 45% of the continent’s land area. Many communities rely on limited groundwater and community water points to meet their water needs, but groundwater is not always a reliable or sustainable source, as it can be depleted, contaminated, or inaccessible due to technical or financial constraints. A 2021 study by UNICEF estimated that women and girls in sub-Saharan Africa collectively spend about 37 billion hours a year collecting water, which is equivalent to more than 1 billion hours a day.The 2023 UN World Water Development Report emphasizes the importance of partnerships and cooperation for water, food, energy, health and climate security in Africa, a region with diverse water challenges and opportunities, low water withdrawals per capita, high vulnerability to climate change, and large investment gap for water supply and sanitation.
In the Meatu District in Shinyanga, an administrative region of Tanzania, water most often comes from open holes dug in the sand of dry riverbeds and it is invariably contaminated.
Water security in Africa is low and uneven, with various countries facing water scarcity, poor sanitation, and water-related disasters. Transboundary conflicts over shared rivers, such as the Nile, pose additional challenges for water management.
However, some efforts have been made to improve water security through various interventions, such as community-based initiatives, irrigation development, watershed rehabilitation, water reuse, desalination, and policy reforms. These interventions aim to enhance water availability, quality, efficiency, governance, and resilience in the face of climate change. Water security is essential for achieving sustainable development in Africa, as it affects numerous sectors, such as agriculture, health, energy, and the environment.
Other Countries with Water Shortages
Water scarcity issues plague many other parts of the world beyond Gaza and Africa. Several examples stand out:
Iraq faces severe water stress impacting agriculture and public health. The Tigris and Euphrates Rivers have dwindled because of upstream damming and climate change. Water distribution is inefficient and wasteful.
Indiagrapples with extensive groundwater depletion, shrinking reservoirs and glaciers, pollution from agriculture and industry, and tensions with Pakistan and China over shared rivers. Monsoons are increasingly erratic with climate change.
Projections show India will be under severe water stress by the end of the decade. Image: WRI.
While the specifics differ, recurrent themes include unsustainable usage, climate change, pollution, lack of infrastructure, mismanagement, poverty, transboundary conflicts, and population growth pressures. But resources often exist; the challenge lies in equitable distribution, cooperation, efficiency, and sustainable practices. Multiple approaches must accommodate local conditions and transboundary disputes.
Water scarcity poses a grave threat to global security on multiple fronts.
First, it can incite conflicts within and between nations over access rights. History contains many examples of water wars, and transboundary disputes increase the risk today in arid regions like the Middle East and North Africa.
Second, water shortages undermine food security. With agriculture consuming the greatest share of water resources, lack of irrigation threatens crops and livestock essential for sustenance and livelihoods. Food price spikes often trigger instability and migrations.
Third, water scarcity fuels public health crises, leading to social disruptions. Contaminated water spreads diseases like cholera and typhoid. Poor sanitation and hygiene due to water limitations also increase illness. The Covid-19 pandemic underscored the essential nature of water access for viral containment.
Finally, water shortages hamper economic growth and worsen poverty. Hydroelectricity, manufacturing, mining, and other water-intensive industries suffer. The World Bank estimates that by 2050, water scarcity could cost some regions 6% of gross domestic product (GDP), entrenching inequality. Climate migration strains nations. Overall, water crises destabilize societies on many levels if left unaddressed.
Solutions and Recommendations
Tackling the global water crisis requires both local and international initiatives across infrastructure, technology, governance, cooperation, education, and funding.
First, upgrading distribution systems, sewage treatment, dams, desalination, watershed restoration, and irrigation methods could improve supply reliability and quality while reducing waste. Community-based projects often succeed by empowering local stakeholders.
Second, emerging technologies like low-cost water quality sensors, affordable desalination, precision agriculture, and recyclable treatment materials could help poorer nations bridge infrastructure gaps. However, funding research and making innovations affordable remains a key obstacle.
Third, better governance through reduced corruption, privatization, metering, pricing incentives, and integrated policy frameworks could improve efficiency. But human rights must be protected by maintaining affordable minimum access.
Fourth, transboundary water-sharing treaties like those for the Nile and Mekong Rivers demonstrate that diplomacy can resolve potential conflicts. But political will is needed, along with climate change adaptation strategies.
Fifth, education and awareness can empower conservation at the individual level. Behaviour change takes time but can significantly reduce household and agricultural usage.
Finally, increased financial aid, public-private partnerships, better lending terms, and innovation prizes may help nations fund projects. Cost-benefit analyses consistently find high returns on water security investments.
In summary, sustainable solutions require combining new technologies, governance reforms, education, cooperation, and creative financing locally and globally.
Conclusion
The global water crisis threatens the well-being of billions of people and the stability of nations worldwide. Key drivers include unsustainable usage, climate change, pollution, lack of infrastructure, poverty, weak governance, and transboundary disputes. The multiple impacts span public health, food and energy security, economic growth, and geopolitical conflicts.
While daunting, this crisis also presents opportunities for innovation, cooperation, education, and holistic solutions. With wise policies and investments, water security can be achieved in most regions to support development and peace. But action must be accelerated on both global and community levels before the stresses become overwhelming. Ultimately, our shared human dependence on clean water demands that all stakeholders work in unison to create a water-secure future.
Even in countries with adequate water resources, water scarcity is not uncommon. Although this may be due to a number of factors — collapsed infrastructure and distribution systems, contamination, conflict, or poor management of water resources — it is clear that climate change, as well as human factors, are increasingly denying children their right to safe water and sanitation.
Water scarcity limits access to safe water for drinking and for practising basic hygiene at home, in schools and in health-care facilities. When water is scarce, sewage systems can fail and the threat of contracting diseases like cholera surges. Scarce water also becomes more expensive.
Water scarcity takes a greater toll on women and children because they are often the ones responsible for collecting it. When water is further away, it requires more time to collect, which often means less time at school. Particularly for girls, a shortage of water in schools impacts student enrolment, attendance and performance. Carrying water long distances is also an enormous physical burden and can expose children to safety risks and exploitation.
UNICEF/UNI315914/Haro Niger, 2020. Early in the morning, children go to the nearest water point to fetch water, 15 kilometres away from their home in Tchadi village.
Key facts
Four billion people — almost two thirds of the world’s population — experience severe water scarcity for at least one month each year.
Over two billion people live in countries where water supply is inadequate.
Half of the world’s population could be living in areas facing water scarcity by as early as 2025.
Some 700 million people could be displaced by intense water scarcity by 2030.
By 2040, roughly 1 in 4 children worldwide will be living in areas of extremely high water stress.
UNICEF’s response
As the factors driving water scarcity are complex and vary widely across countries and regions, UNICEF works at multiple levels to introduce context-specific technologies that increase access to safe water and address the impacts of water scarcity. We focus on:
Identifying new water resources: We assess the availability of water resources using various technologies, including remote sensing and geophysical surveys and field investigations.
Improving the efficiency of water resources: We rehabilitate urban water distribution networks and treatment systems to reduce water leakage and contamination, promoting wastewater reuse for agriculture to protect groundwater.
Planning for urban scarcity: We plan for future water needs by identifying available resources to reduce the risk of cities running out of water.
Expanding technologies to ensure climate resilience: We support and develop climate-resilient water sources, including the use of deeper groundwater reserves through solar-powered water networks. We also advance water storage through small-scale retention structures, managed aquifer recharge (where water is pumped into underground reserves to improve its quality), and rainwater harvesting.
Changing behaviours: We work with schools and communities to promote an understanding of the value of water and the importance of its protection, including by supporting environmental clubs in schools.
Planning national water needs: We work with key stakeholders at national and sub-national levels to understand the water requirements for domestic use and for health and sanitation, and advocate to ensure that this is reflected in national planning considerations.
Supporting the WASH sector: We develop technical guidance, manuals and online training programmes for WASH practitioners to improve standards for water access.
To mark World Water Week 2025, new report highlights persistent inequalities, with vulnerable communities left behind.
Despite progress over the last decade, billions of people around the world still lack access to essential water, sanitation, and hygiene services, putting them at risk of disease and deeper social exclusion.
A new report: Progress on Household Drinking Water and Sanitation 2000–2024: special focus on inequalities –launched by WHO and UNICEF during World Water Week 2025 – reveals that, while some progress has been made, major gaps persist. People living in low-income countries, fragile contexts, rural communities, children, and minority ethnic and indigenous groups face the greatest disparities.
Ten key facts from the report:
Despite gains since 2015, 1 in 4 – or 2.1 billion people globally – still lack access to safely managed drinking water*, including 106 million who drink directly from untreated surface sources.
3.4 billion people still lack safely managed sanitation, including 354 million who practice open defecation.
1.7 billion people still lack basic hygiene services at home, including 611 million without access to any facilities.
People in least developed countries are more than twice as likely as people in other countries to lack basic drinking water and sanitation services, and more than three times as likely to lack basic hygiene.
In fragile contexts**, safely managed drinking water coverage is 38 percentage points lower than in other countries, highlighting stark inequalities.
While there have been improvements for people living in rural areas, they still lag behind. Safely managed drinking water coverage rose from 50 per cent to 60 per cent between 2015 and 2024, and basic hygiene coverage from 52 per cent to 71 per cent. In contrast, drinking water and hygiene coverage in urban areas has stagnated.
Data from 70 countries show that while most women and adolescent girls have menstrual materials and a private place to change, many lack sufficient materials to change as often as needed.
Adolescent girls aged 15–19 are less likely than adult women to participate in activities during menstruation, such as school, work and social pastimes.
In most countries with available data, women and girls are primarily responsible for water collection, with many in sub-Saharan Africa and Central and Southern Asia spending more than 30 minutes per day collecting water.
As we approach the last five years of the Sustainable Development Goals period, achieving the 2030 targets for ending open defecation and universal access to basic water, sanitation and hygiene services will require acceleration, while universal coverage of safely managed services appears increasingly out of reach.
“Water, sanitation and hygiene are not privileges, they are basic human rights,” said Dr Ruediger Krech, Director a.i, Environment, Climate Change and Health, World Health Organization. “We must accelerate action, especially for the most marginalized communities, if we are to keep our promise to reach the Sustainable Development Goals.”
“When children lack access to safe water, sanitation, and hygiene, their health, education, and futures are put at risk,” said Cecilia Scharp, UNICEF Director of WASH. “These inequalities are especially stark for girls, who often bear the burden of water collection and face additional barriers during menstruation. At the current pace, the promise of safe water and sanitation for every child is slipping further from reach – reminding us that we must act faster and more boldly to reach those who need it most.”
This latest update – produced by WHO/UNICEF Joint Monitoring Programme for Water Supply, Sanitation and Hygiene (JMP) – provides new national, regional and global estimates for water, sanitation and hygiene services in households from 2000 until 2024. The report also includes expanded data on menstrual health for 70 countries, revealing challenges that affect women and girls across all income levels.
The report is being launched during World Water Week 24-28 August 2025, the leading annual conference on global water issues, and bringing together stakeholders from across sectors to accelerate progress towards the Sustainable Development Goals.
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*JMP definition of ‘Safely managed drinking water and sanitation services’: Drinking water from sources located on premises, free from contamination and available when needed, and using hygienic toilets from which wastes are treated and disposed of safely.
**Fragile contexts: Fragility, according to the OECD, is the combination of exposure to risk and insufficient coping capacities of the state, system and/or communities to manage, absorb or mitigate those risks. It occurs in a spectrum of intensity across six dimensions: economic, environmental, human, political, security and societal.
About the JMP The WHO/UNICEF Joint Monitoring Programme for Water Supply, Sanitation and Hygiene (JMP) was established in 1990 and has been tracking global progress for 35 years. It is responsible for monitoring Sustainable Development Goal targets 1.4, 6.1 and 6.2, which call for universal access to safe water, sanitation, hygiene and the elimination of open defecation by 2030.
IMAGE: IMAGE SHOWING FLOW OF WATER AND TREATED WATER.view more CREDIT: PLOS WATER, ET. AL.
University of Pittsburgh Researchers Reveal Hidden Impacts of Drinking Water Treatment on Urban Streams
Aging lead-pipe drinking water systems, along with the public health measures implemented to reduce their risks, are reshaping the chemistry and health of nearby urban streams. New research from University of Pittsburgh biogeochemists, hydrologists, and environmental engineers uncovered previously overlooked environmental impacts of a common water treatment practice: adding orthophosphate to drinking water systems to prevent lead pipe corrosion. Published in PLOS Water, the study reveals that phosphate used in drinking water treatment can leak into urban streams, altering their chemistry and potentially accelerating eutrophication, the process where such nutrients lead to excessive growth of algae and aquatic plants..
And such lead-pipe networks are widespread throughout the Northeast, Great Lakes region and Midwest — meaning as many as 20 million Americans and their nearby streams may face similar challenges.
In collaboration with local water authorities, the scientists studied five urban streams to look for changes in the pre- and post-implementation of orthophosphate-based corrosion control on stream chemistry. Their findings show statistically significant increases in phosphorus and metal concentrations in streamwater following the treatment, indicating that subsurface infrastructure is not a closed system. Phosphorus concentrations in urban streams increased by over 600% following orthophosphate dosing, while trace metals such as copper, iron, and manganese also rose by nearly 3,500%, suggesting co-transport of corrosion byproducts.
“We were surprised by how clearly the effects of drinking water treatment appeared in stream chemistry. This finding suggests that our underground infrastructure isn’t as sealed off from the environment as we often assume,” said first author Dr. Anusha Balangoda, Assistant Teaching Professor in Geology and Environmental Science in the Kenneth P. Dietrich School of Arts & Sciences. “Our study is the first to examine urban stream chemistry and the influence of drinking-water additives.”
“We absolutely need to protect people from lead in drinking water,” said co-author Dr. Emily Elliott, co-founder and chair of the Pittsburgh Water Collaboratory and professor in Geology and Environmental Science. “But we also need to understand how these treatments affect our rivers and ecosystems.” Elliott collaborated with co-authors Sarah-Jane-Haig, an associate professor, and Isaiah Spencer-Williams, a doctoral student, both also in Civil and Environmental Engineering. Their paper, titled “From Pipes to Streams: The Hidden Influence of Orthophosphate Additions on Urban Waterways,” was published November 13 in PLOS Water.
Public-health emergencies arising from corroded, lead-water pipes are nothing new— contaminations have made the news in the past decade in Flint, Michigan, Washington, D.C., and more recently in the study area of Pittsburgh. Phosphate corrosion inhibitors are used in water systems across North America, the United Kingdom, and parts of Europe. The researchers noted that the potential ecological consequences of this dosing of drinking-water system pipes does to streams, rivers, and groundwater remain “largely unexplored, particularly in the U.S.”
The study examined a pathway of phosphorus pollution that has received little attention: leakage from drinking water pipes rather than traditional sources like wastewater discharge or industrial runoff. The researchers monitored five above-ground urban stream reaches, selecting these because most Pittsburgh streams are buried in an underground pipe network, and collected detailed water chemistry samples monthly over a two-year period spanning before, during, and after orthophosphate treatment implementation (February 2019 to June 2020). They also conducted nutrient addition bioassays at three key time points, using both streamwater and tap water controls, to assess the ecological impacts on algal growth.
The scientists offer four corrective actions to address phosphate leakage from buried water infrastructure systems:
1. Repair Aging Infrastructure. Urgently address the issue of drinking water pipe networks losing 40-50% of treated water through leaks and breaks, thereby preventing phosphate-enriched water from reaching urban streams and groundwater.
2. Upgrade Wastewater Treatment. Implement tertiary treatment processes at wastewater treatment plants to remove excess phosphorus. The study shows effluent phosphorus increased 26% after dosing began, yet many plants lack phosphorus removal capabilities that can achieve an 80-99% reduction.
3. Optimize Dosing Concentrations. Determine the minimum effective orthophosphate concentration that protects human health from lead exposure while minimizing ecological harm to receiving waters.
4. Develop Innovative Approaches to Monitor Infrastructure-Ecosystem Interactions. Create new monitoring and assessment methods to understand how additives in drinking water systems reach and affect urban streams through subsurface connections.
“Pittsburgh isn’t unique—millions of Americans are served by water systems with lead pipes and aging infrastructure,” Elliott said. “Our findings suggest this issue extends far beyond one city, particularly in the Midwest and Northeast where both lead pipes and phosphate treatment are common. We need a national conversation about infrastructure and water quality.”
This research was supported by the National Science Foundation RAPID funding program (grant NSF No. 1929843), as well as the Pittsburgh Water Collaboratory. The Pittsburgh Water and Sewer Authority contributed drinking water sample collection, chemical analysis and water treatment information.
# # #
JOURNAL
PLOS Water
METHOD OF RESEARCH
Data/statistical analysis
SUBJECT OF RESEARCH
Not applicable
ARTICLE TITLE
From Pipes to Streams: The Hidden Influence of 2 Orthophosphate Additions on Urban Waterways
ARTICLE PUBLICATION DATE
13-Nov-2025
COI STATEMENT
None
Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.
There is urgency for the seven states that rely on the Colorado River to reach an agreement on how to keep water levels high enough in its two major reservoirs. Climate change is threatening water delivery and power systems as the region becomes drier.
Lake Mead, 2022 | Credit: NASA Earth Observatory
The states—Colorado, Utah, Wyoming, New Mexico, Arizona, Nevada, and California—have until next month to agree on alternatives to keep the system afloat for the next couple of decades and submit them to the Bureau of Reclamation. If they don’t, the bureau will propose its own plan for cuts to allocations from the river, which supplies 40 million people and agriculture.
However, there’s a wrinkle in the negotiations. A report released by the bureau on February 8 concluded that 1.3 million acre-feet of water was lost annually to evaporation and transpiration in the three Lower Basin states of Arizona, California, and Nevada. Water lost to evaporation and transpiration has not been considered under the current rules. Despite evaporation and transpiration, the three lower states have continued to draw down from the reservoirs that are threatened by aridification.
Now, all of the Colorado River Basin states, except California, have submitted a letter to the federal government proposing that in times of low water levels, there would be cuts in allocations—most heavily to California—that take evaporation and transpiration into account. The Los Angeles Timesreports that agencies in Southern California would be required to endure the largest cuts, up to 32 percent for evaporation losses if Lake Powell and Lake Mead hit crisis levels. California has proposed a more modest plan that it argues does not rewrite the rules of the river, which are based on historic water rights. Because of the winter snowpack last year, recent storms, and conservation, water levels at Lake Mead, the country’s largest reservoir, are currently about 40 feet higher than was projected.
Added to the federal government’s deadline for the states to come up with a plan for cutbacks, is the fear that a different administration after the November election could change those involved at the federal level.
A portion (looking south) of the 152-mile Friant-Kern Canal, an aqueduct to convey water to augment agriculture irrigation on the east side of the San Joaquin Valley, is viewed on July 8, 2021, thirty minutes east of Fresno, Calif.
The headlines suggested a comparison with the “Zero Day” announcement in Cape Town, South Africa, during a drought in 2018. That was the projected date when water would no longer be available at household taps without significant conservation. Cape Town avoided a water shutoff, barely.
While California’s announcement represents uncharted territory and is meant to promote water conservation in what is already a dry water year, there is more to the story.
California’s drought solution
California is a semi-arid state, so a dry year isn’t a surprise. But a recent state report observed that California is now in a dry pattern “interspersed with an occasional wet year.” The state suffered a three-year drought from 2007 to 2009, a five-year drought from 2012 to 2016, and now two dry years in a row; 2020 was the fifth-driest year on record, and 2021 was the second-driest.
Coming into the 2022 water year – which began Oct. 1 – the ground is dry, reservoirs are low and the prediction is for another dry year.
Over a century ago, well before climate change became evident, officials began planning ways to keep California’s growing cities and farms supplied with water. They developed a complex system of reservoirs and canals that funnel water from where it’s plentiful to where it’s needed.
Part of that system is the State Water Project.
First envisioned in 1919, the State Water Project delivers water from the relatively wetter and, at the time, less populated areas of Northern California to more populated and drier areas, mostly in Southern California. The State Water Project provides water for 27 million people and 750,000 acres of farmland, with about 70% for residential, municipal and industrial use and 30% for irrigation. There are 29 local water agencies – the state water contractors – that helped fund the State Water Project and in return receive water under a contract dating to the 1960s.
While the State Water Project is important to these local water agencies, it is usually not their only source of water. Nor is all water in California supplied through the State Water Project. Most water agencies have a portfolio of water supplies, which can include pumping groundwater.
What does 0% mean?
Originally, the State Water Project planned to deliver 4.2 million acre-feet of water each year. An acre-foot is about 326,000 gallons, or enough water to cover a football field in water 1 foot deep. An average California household uses around one-half to 1 acre-foot of water per year for both indoor and outdoor use. However, contractors that distribute water from the State Water Project have historically received only part of their allocations; the long-term average is 60%, with recent years much lower.
Based on water conditions each year, the state Department of Water Resources makes an initial allocation by Dec. 1 to help these state water contractors plan. As the year progresses, the state can adjust the allocation based on additional rain or snow and the amount of water in storage reservoirs. In 2010, for example, the allocation started at 5% and was raised to 50% by June. In 2014, the allocation started at 5%, dropped to 0% and then finished at 5%.
This year is the lowest initial allocation on record. According to the state Department of Water Resources, “unprecedented drought conditions” and “reservoirs at or near historic lows” led to this year’s headline-producing 0% allocation.
That’s 0% of each state water contractor’s allocation; however, the department committed to meet “unmet minimum health and safety needs.” In other words, if the contractors cannot find water from other sources, they could request up to 55 gallons per capita per day of water to “meet domestic supply, fire protection and sanitation needs.” That’s about two-thirds of what the average American uses.
The department is also prioritizing water for salinity control in the Sacramento Bay Delta area, water for endangered species, water to reserve in storage and water for additional supply allocations if the weather conditions improve.
Under the current plan, there will be no water from the State Water Project for roughly 10% of California’s irrigated land. As a result, both municipal and agricultural suppliers will be seeking to conserve water, looking elsewhere for water supplies, or not delivering water. None are easy solutions.
Those who can afford to dig deeper wells have done so, while others have no water as their wells have gone dry. During the 2012-2016 drought, the Public Policy Institute of California found that a majority of affected households that lost water access from their wells were in “small rural communities reliant on shallow wells – many of them communities of color.”
As someone who has worked in California and the Western U.S. on complex water issues, I am familiar with both drought and floods and the challenges they create. However, the widespread nature of this year’s drought – in California and beyond – makes the challenge even harder.
This “zero allocation” for California’s State Water Contractors is an unprecedented early warning, and likely a sign of what’s ahead.
A recent study warned that the snowpack in Western states like California may decline by up to 45% by 2050, with low- and no-snow years becoming increasingly common. Thirty-seven cities in California have already issued moratoriums on development because of water supply concerns.
If voluntary conservation does not work, enacting mandatory conservation measures like San Jose’s tough new drought rules may be needed. The state is now weighing emergency regulations on water use, and everyone is hoping for more precipitation.
Lara B. Fowler, Senior Lecturer in Law and Assistant Director for Outreach and Engagement, Penn State Institutes of Energy and the Environment, Penn State
GET WET! 