NRDC Map Shows Populations With Lead Contamination in Tap Water

A new map from the Natural Resources Defense Council (NRDC) highlights U.S. populations with higher levels of lead in drinking water.

The map builds on recently released data from the U.S. Environmental Protection Agency (EPA) that revealed millions of people in the U.S. had lead in their water systems for at least some of the period of 2021 through 2024. 

According to the EPA data, more than 250 million people had water systems with lead detected at or above 1 part per billion (ppb), the maximum level of exposure for children as recommended by the American Academy of Pediatrics. More than 112 million people’s water systems had lead levels over 5 ppb, the maximum level allowed in bottle water.

Further, 44 million people had water systems with lead at or above 10 ppb, the new lead action level by the EPA that will take effect in 2027, while nearly 13 million people got water from systems with lead levels at or above 15 ppb, the current lead action level set by the EPA.

More than 72 million people in the U.S. had water systems with lead levels high enough to be considered a “health-based violation” by the EPA, NRDC reported.

“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,” Erik Olson, senior strategic director for health at NRDC, said in a statement. “Removing lead from drinking water is a solvable problem, yet water utilities are suing to block requirements to replace lead water pipes.” 

Although some organizations set a maximum level of exposure to lead in tap water, national and global organizations all agree that no exposure to lead is safe.

In addition to developing a map on high lead levels across the U.S., NRDC also compiled information on the congressional districts and water systems with the highest lead levels. According to the council’s analysis, the top 10 congressional districts with the highest populations exposed to water systems with lead levels span both Republican and Democratic leadership, emphasizing the need for better protections across the board.

The analysis also revealed the water systems with 90th percentile lead amounts exceeding the current lead action level of 15 ppb. These water systems include the Veolia Water New Jersey Hackensack, which had the greatest population served in this list, and the Boston Water and Sewer Commission (MWRA), which had the highest recorded 90th percentile lead amount of 99.5 ppb.

These levels do not mean all people using a specific water system are drinking or using tap water with that level of lead, nor that the lead levels are that specific amount all the time. However, as NRDC pointed out, the only way to know the exact lead levels per household is with frequent testing.

According to NRDC, these findings highlight a need for implementing the EPA’s Lead and Copper Rule Improvements adopted in 2024 in addition to further investments in water infrastructure improvements nationwide.

As Earthjustice reported, the Lead and Copper Rule, as well as the 2024 Lead Paint Dust Rule, are vulnerable under the current administration. If these regulations are not upheld, there could be greater risk of higher lead exposure in households.

“We need to save people’s lives, and lead [exposure] protections do exactly that,” Dionna Brown, national director of Youth Environmental Justice Policy at the nonprofit Young, Gifted, and Green, said in a statement. “At this point, we are already playing with people’s lives. This is bigger than just being left versus right. Humanity should not be political.”