Worrisome Lead Levels in Drinking Water Systems Serving More Than 250 Million People

WASHINGTON, D.C. - New data released by the U.S. Environmental Protection Agency (EPA) show hundreds of millions of people are drinking water from water systems reporting problematic lead levels. NRDC (Natural Resources Defense Council) has released a map showing the populations of people who get their tap water from systems that reported that they had detected widely varying levels of lead in the period of 2021–2024. The map shows the congressional districts most heavily affected, highlighting districts with members of both political parties, including from California, Colorado, Illinois, Indiana, Michigan, New Jersey, New York, North Dakota, Ohio, and Tennessee. There is no safe level of lead exposure.

“It’s unacceptable that in 2025 the tap water for hundreds of millions of people could contain worrisome amounts of lead, a toxic chemical that is unsafe at any level,” said Erik D. Olson, senior strategic director for health at NRDC. “Removing lead from drinking water is a solvable problem, yet water utilities are suing to block requirements to replace lead water pipes. If the Trump EPA really wants to protect clean water, it should stand up today and say it will defend the agency’s lead in tap water standards in court.” 

The Trump EPA has not yet said whether it will support the Lead and Copper Rule Improvements announced last October, which would require virtually every lead water pipe to be replaced in a decade. The pending litigation over that rule is now on hold because the Trump Administration requested a delay. The administration has not said whether it will defend the rule. The litigation was filed by the water utility trade association AWWA, which is suing to block the rule from taking effect; NRDC and its partners have moved to intervene to defend the rule.

Data reported to the EPA show the 90th percentile lead levels found by water utilities across the nation. The data demonstrate that for at least some of the time during 2021–2024:

• 251.2 million people’s systems detected lead at or above the American Academy of Pediatrics’ recommended maximum level for children in school of 1 ppb—that’s 81 percent of the U.S. population served by community water systems.
• 112.3 million people got their water from systems that detected lead at or above the 5 ppb lead level that is the maximum allowed in bottled water—or 36 percent of the population served by these water systems.
• 44 million people got their water from systems detecting lead at or above the EPA’s new 10 ppb lead action level (which becomes effective in 2027)—or 14 percent of the population served by these systems.
• 12.9 million people got their water from systems detecting lead at or above the EPA’s current lead action level of 15 ppb (which remains in effect until 2027)—or about 4 percent of the population served by these systems.
• In addition, a total of 72.6 million people across the nation (about 23.5 percent of the population served by community water systems) got their water from systems that had what the EPA classifies as a “health-based violation” for lead per its existing Lead and Copper Rule during this 2021–2024 period.

Background on lead in drinking water

Only zero parts per billion (ppb) of lead is safe in tap water. The EPA, U.S. Centers for Disease Control and Prevention, American Academy of Pediatrics, World Health Organization, and other experts all agree on this. Lead exposure can cause permanent damage to the developing brains of fetuses and children, resulting in a loss of IQ points, attention deficit hyperactivity disorder, learning problems, low birth weight, and related complications; in adults, it can adversely affect the kidneys and reproductive systems, cause heart disease, and lead to fatal heart attacks, among other harms.

Utilities report their 90th percentile lead levels, which is the basis for the populations served by systems with various lead levels noted here. Not everyone served by these water systems were drinking water at the levels noted, though a significant portion of the people served by those systems were. Many homes have lead service lines or lead-containing indoor plumbing, and lead levels at a single tap can vary significantly from day to day because lead is intermittently released into tap water. In other words, if a water system detects significant lead levels in some of the homes it serves, it is clear that many other homes also have significant lead in their tap water. But most utilities test only a tiny percentage of the homes they serve. The only way to know what lead levels are in a specific home is to repeatedly test multiple samples over time from the home’s taps.

Lead-contaminated water is a bipartisan problem affecting rural & urban districts

As is highlighted in the map, and the tables below showing both Republican and Democratic congressional districts with lead tap water issues, this is a problem affecting people from all backgrounds and communities. It affects urban and rural districts, and is not a partisan issue. 

REPUBLICAN CONGRESSIONAL DISTRICTS WITH LARGEST POPULATIONS SERVED BY WATER SYSTEMS WITH LEAD 90th PERCENTILE LEVELS => 10 PPB (NEW EPA ACTION LEVEL, EFFECTIVE 2027) (2021–2024) DEMOCRATIC CONGRESSIONAL DISTRICTS WITH LARGEST POPULATIONS SERVED BY WATER SYSTEMS WITH LEAD 90th PERCENTILE LEVELS => 10 PPB (NEW EPA ACTION LEVEL, EFFECTIVE 2027) (2021–2024)

Additional resources

• Finding Lead Water Pipes: New NRDC Map Shows the Hot Spots in Every State
• Welcoming the EPA’s New Lead in Tap Water Rule: An Overview
• Water Utility Groups Seek to Dismantle Public Health Protections
• American Water Works Association et al. v. EPA (Lead and Copper Rule Improvements)
• How to Find Out If Your Home Has Lead Service Lines

NRDC (Natural Resources Defense Council) is an international nonprofit environmental organization with more than 3 million members and online activists. Established in 1970, NRDC uses science, policy, law and people power to confront the climate crisis, protect public health and safeguard nature. NRDC has offices in New York City, Washington, D.C., Los Angeles, San Francisco, Chicago, Beijing and Delhi (an office of NRDC India Pvt. Ltd).