Hazardous H2O: Lead Safety and the ‘Hidden 10%’

When Tasian Lyles and her four children moved to a house in the Fairfax neighborhood of Cleveland, she thought she was doing what was best for her family. The house was big, with plenty of room for them to grow; she was on a rent-to-own track and she also thought she was escaping the dangers of a house with a lead water line. So, when she found out that water in her new home would also be delivered through lead pipes, she felt betrayed. “Why? Why Us?” Lyles wondered. 

Lyles first had her son’s blood lead levels tested in 2022 when he was 2 years old. Pediatricians recommend testing children’s blood lead levels at 12 and 24 months old, especially in Cleveland where most houses were built before 1978, when the federal government banned the use of lead-based paint. Even low concentrations of lead in blood can impact children’s academic achievement, IQ scores, attention and social behaviors, according to the American Academy of Pediatrics. The test found the concentration of lead in his blood to be 4.3 micrograms per deciliter (μg/dL), well above the 3.5 μg/dL threshold where the Centers for Disease Control and Prevention recommends action to reduce further contamination.

“I felt cheated, especially with my baby boy,” Lyles said. As her son has gotten older, she has been on high alert. She wonders if her son’s shorter attention span and problems with his memory are symptoms of elevated blood lead levels. Lyles feels landlords should have to disclose the presence of lead service lines to renters, and that the city should play a more active role in protecting residents from the dangers of lead in their drinking water. “They are leaving people in the dark, especially when it comes to their babies,” she said. 

However, Americans across the country get their drinking water from more than 9 million service lines that contain lead pipes, and many are unaware that they face any risk. That’s often because in communities where lead pipes are present, utilities adhere to a decades-old regulation that allows them to obscure their most troubling data.

In 1991, following a rush of new research on the impacts of lead in the body, the Environmental Protection Agency adopted the Lead and Copper Rule to enforce a reduction of those metals in the country’s drinking water. It requires that utilities test their water and ensure that in 90% of the samples they collect — the 90th percentile — the concentration of lead is no more than 15 parts per billion. What’s troubling is what happens to the 10% of samples with lead concentrations above that threshold: They remain hidden. Under the Lead and Copper Rule, this data can be withheld from the public, no matter how high it is, as long as the other 90% remains below 15 ppb.

Today, millions of people like Lyles are subjected to misleading messaging about what’s in their water and left unaware of astronomical levels of lead hidden in their communities’ drinking water data.

Hiding the worst of it

Among American cities, Cleveland ranks behind only Chicago in concentration of lead water lines, with more than 230,000 known lead service lines delivering water to residents across its distribution system. New York City, Detroit and Milwaukee also have high concentrations. As with those cities, lead was the most common material used in Cleveland’s plumbing until the late 1940s. Since 2021, the Cleveland Water Department has received more than $61 million to replace its lead lines through the Bipartisan Infrastructure Law, the Biden-era legislation that pumped $15 billion into replacing all of the country’s remaining lead water lines within 10 years. Since taking office, President Donald Trump’s administration has delayed tens of millions of dollars in promised federal funds, and Republican lawmakers have pushed to ban the government from requiring the replacement of lead water lines. 

In Cleveland, the promise of lead-free plumbing is not expected to be realized until 2037. Meanwhile, homeowners are saddled with the burden of replacing lead-laden pipes themselves, at a cost of over $10,000. And for renters like Lyles, there is no law requiring landlords to disclose if their property has a lead line.

Under current regulations for the Lead and Copper Rule, Cleveland Water must collect water samples from the taps of 50 homes across the water system once every three years. Residents are sent a container and instructions to collect the first liter of water that flows from their tap after the water has been sitting stagnant for at least six hours. 

If more than 10% of tap samples show lead concentrations above 15 ppb, the water utility is required to inform residents and resolve the problem. It’s important to note, however, that the 15-ppb threshold “was never intended to be a health-based standard,” said Bruce Lanphear, a public health physician who has studied lead poisoning for 30 years. At the time the rule was adopted, the science was clear that any amount of lead in drinking water could be dangerous.

“There is no safe level of lead,” he said.

The number was set only to judge the effectiveness of corrosion control measures, but many water utilities have since equated it as the safe level for exposure. Facing a lack of resources and fear of legal retaliation from water utilities, “The EPA has consistently erred on the side of feasibility as opposed to science,” Lanphear said.

Crucially, the rule also allows utilities to base their remediation actions on the 90th percentile of sampling data and omit the final 10% of tap samples from public notice, no matter how high they skyrocket. 

“Using the 90th percentile means that we’re hiding very high lead levels from communities all the time,” said Elin Betanzo, with Safe Water Engineering, a public interest drinking water firm.

Anne Vogel, the director of the Ohio EPA, tried to allay residents’ concerns in a 2024 interview. “I wouldn’t want anybody to think they’re going to find screaming high levels of lead in their water; that’s just not the case,” she said. 

The numbers tell a different story. 

A public records request to the Ohio EPA shows Cleveland Water samples taken since 2019 with lead concentrations measuring well above 15 ppb, some over 450 ppb. One tap sample from 2024, which fell within the last 10% of samples and was therefore omitted from public disclosure, skyrocketed to 1,997 ppb — over 130 times the level at which the EPA requires utilities to take mitigating action, and 1,997 ppb more than the safe level of exposure to lead. Cleveland Water does prioritize the removal of lead service lines from houses if tests reveal high levels, and that lead service line was replaced within 48 hours of the high measurement.

Public records requests to Chicago, Detroit and Milwaukee revealed tap samples several times that of the EPA action limit, but none as high as those found in Cleveland. The city’s astoundingly high sample was probably the result of lead that had flaked off from inside the pipes, sending small particles floating through the system. Like most water utilities across the country, Cleveland Water uses orthophosphate, a form of phosphorus that reacts with lead to form a protective layer to control corrosion and reduce the amount of lead that enters customers drinking water. But, clearly, corrosion control alone is not a perfect solution to Cleveland’s lead service line crisis.

“Lead particles can have astronomical levels of lead in them, and one of the really tricky things about the release of lead particles from plumbing is that it tends to happen erratically and unpredictably,” said Yanna Lambrinidou, a medical anthropologist and co-founder of the Campaign for Lead Free Water, a national advocacy organization. “It’s a bit of a game of Russian roulette, where somebody can open their tap 10 times and collect water that has literally no lead in it, and then the 11th time a particle can fall in, and suddenly that water can have astronomical levels of lead, including levels that exceed 5,000 ppb, which meets the EPA criteria for hazardous waste,” she said. If that particularly dangerous use of the tap falls outside the 90th percentile of water tests, however, it can go unreported to the public per the Lead and Copper Rule.

Research has shown that it would take over 1,200 samples from a single tap to accurately assess the average levels of lead residents are exposed to in that home, but most water utilities test homes just twice over the course of three years. “Nobody discloses that a one-time test can very easily miss worst-case levels that people are exposed to,” Lambrinidou said. 

While the 90th percentile measurement allows water utilities to hide the worst of their tap samples from the public, the Lead and Copper Rule has further inadequacies that help water utilities keep their monitoring samples low enough to avoid exceedances.

Murky messaging

On a rainy Thursday in March, UNDIVIDED, a nonprofit citizen action group working to inform the public about lead in drinking water across Cleveland, stood outside of the MidTown Dave’s Market handing out water filters and informational pamphlets to local shoppers. UNDIVIDED has partnered with Case Western Reserve University’s Center on Poverty and Community Development to provide lead-certified filters to community members in need. They meet every Thursday and hand out filters most weeks.

UNDIVIDED member Tanis Quach questions why Cleveland residents are still seeing lead poisoning at nearly four times the national average when the dangers have been known since at least the time of the ancient Greeks. Noting that modern lead service line crises like those in Flint and Benton Harbor, Michigan, and Washington, D.C., were especially detrimental to people in low income and Black communities, Quach expressed frustration over the lack of action to address such a persistent and well-known problem. “The government is allowing this direct harm to communities,” Quach said. “In 2025, how can you say lead exposure is not an intentional form of structural violence?” 

Through their weekly meetings and lead filter distribution, UNDIVIDED is looking to engage the Cleveland community about lead poisoning and lead service lines. “We need to value people who are being most victimized and let their opinion have the same value as any corporate executive. We need to start reversing the value system,” Quach said.

In mailers it sends to residents, Cleveland Water assures that “customers can be confident that the water delivered to their home is safe,” even as their data shows that the water that customers are drinking from their taps can have astronomical levels of lead. UNDIVIDED and public health experts are calling for more honest messaging from water utilities about the safety of drinking water being delivered to customers’ taps. 

Citing the use of treatment techniques in providing safe drinking water to customers, Danielle Miklos, manager of communications at Cleveland Water, said, “Drinking water is lead-free when it leaves our treatment plants and when it is delivered to our customers’ homes.” But the department’s own data shows some residents have received water with dangerously high concentrations of lead. 

“Water utilities prioritize not making their residents panic,” said Betanzo, of Safe Water Engineering. “When they prioritize not making their residents panic, it means they are allowing them to be exposed every single day to a potent, irreversible neurotoxin with no safe level of exposure.”

More transparency from Cleveland Water about the state of lead service lines would empower residents with the knowledge needed to protect themselves. “Despite our best efforts, water utilities have been resisting honest messaging to people that the best way to protect themselves from lead in water is the use of point-of-use lead certified filters,” Lambrinidou said.

Skewing the data

Part of the challenge is baked into how and where water samples are collected. Public records requests show that Cleveland’s data does not accurately represent the lead concentrations residents are probably being exposed to, because, per the Lead and Copper Rule sampling procedure, residents are asked to collect only the first liter of water that flows from their taps.

“The first liter doesn’t represent the water that’s been sitting for a very long time in the lead service line where larger quantities of lead can dissolve into the water,” Betanzo said. That is because the water taken from the first liter has usually been sitting in the plumbing of the house instead of the service line itself. Research shows that collecting both first and fifth liter samples provides a more accurate picture.

After the Flint water crisis, Michigan changed its procedure to include first and fifth liter sampling for tap samples. The sample with the highest measurement between the two is then counted toward the city’s final 90th percentile measurement. In many instances, sampling data from Detroit shows that lead concentrations double or triple between the first and fifth liters.

Cleveland, Chicago and Milwaukee test only the first liter of water.

To add to the uncertainty, the Lead and Copper Rule requires that only half the homes chosen as tap sampling sites have lead service lines. There are also no regulations to direct whether a chosen site’s lines are fully or partially lead, meaning portions can be made of an alternative material, like copper. And the other 50% of homes sampled can rely on copper pipes with lead solder installed between 1982 and 1989. 

Pairing Cleveland’s 2021 tap sampling data with Cleveland Water’s Water Service Line Inventory Map highlights how that regulation skews data. Out of the 58 sites tested, 15 had no lead service lines, five had resident-owned service lines with an unknown material and non-lead lines on the portions owned by the city, 16 were lead on the city side and non-lead on the resident side, 15 were unknown on the resident side and lead on the city side, one had completely unknown materials, one used galvanized steel on the owner side and lead on the city side and one used lead on the resident side and non-lead on the city side. Only four of the sampling sites depended on fully lead service lines on both the city and residential sides.

By primarily conducting tap samples in houses with no lead service line or service lines that are partially lead on the city side, Cleveland’s data does not accurately represent the lead concentrations residents are likely being exposed to.

Additionally, mapping the sample sites for Cleveland Water’s 2021 samples shows that most tap samples were not taken in areas with the highest concentrations of lead service lines. Several tests were conducted in the comparatively affluent Bay Village and Fairview Park suburbs, where less than half of homes receive water through lead service lines. Of samples taken in 2024, 16 were from service lines in which only the city side contained lead, and only five samples were taken from service lines made fully of lead, according to the department’s inventory map. 

The historic harm that lead service lines have caused to communities across the country cannot be undone, but improvements are being made to reduce future harm. In 2024, the EPA revised the Lead and Copper Rule with updates that are planned to go into effect in 2027. Among other things, the updated rule will require both first- and fifth-liter sampling, and the 90th percentile threshold will drop from 15 ppb to 10 ppb. The new service line inventory map will also allow residents to look up their homes to see if they have lead service lines, report the material of their service line and to volunteer to become a tap sampling site.

After experiencing the impacts lead can have on her family, Lyles wants other families, especially renters, to stay vigilant when choosing their home. “Check your water line and make sure it doesn’t have lead. You will be sorry later if you don’t. No one’s telling us, so we have to do it ourselves, for the safety of our children,” she said.