Twenty-five Metro Detroit communities exceeded Michigan’s lead action level for drinking water since 2018, according to state compliance data analyzed by a drinking water engineer and reviewed by Planet Detroit.

The communities all receive water treated by the Great Lakes Water Authority, or GLWA. Despite repeated exceedances, regulators have not required the distribution of water filters, something experts say is warranted.

The data is submitted to the state by community water systems as part of compliance with Michigan’s Lead and Copper Rule, which requires systems to identify and remove lead pipes and expand testing and transparency.

When lead levels in Benton Harbor’s drinking water were found to be high in 2018, it drew national attention. Residents petitioned the EPA to take action.

Water experts say authorities need to learn the lessons of the lead crises in Flint and Benton Harbor and move more quickly to put public health first.

Water systems that exceed the lead action level are required to notify the public, conduct additional monitoring, and increase lead line replacements, which are tracked by Planet Detroit.

Water systems with lead level exceedances or other problems must test for lead every six months, while others are eligible for annual or triennial testing, according to Michigan Department of Environment, Great Lakes, and Energy (EGLE) spokesperson Scott Dean.

The rule requires requires action when the 90th percentile of all samples within a monitoring period show lead at more than 12 parts per billion (ppb).

The 90th percentile value indicates the level below which 90% of samples in a community fall.

Michigan lowered its lead action level from 15 ppb to 12 ppb in 2025.

The Environmental Protection Agency’s action level for drinking water is 15 ppb, higher than Michigan’s 12 ppb. The federal action level is set to decrease to 10 ppb in 2027.

Multiple Metro Detroit communities known to have lead service lines showed lead levels above state limits between 2018 and 2025.

GLWA treats the source water that the systems receive with orthophosphate, a corrosion-control measure that minimizes the amount of lead released from lead service lines connecting some homes to water mains.

“Everybody who gets their water from the Great Lakes Water Authority has water that’s treated the same way,” said Elin Betanzo, a Michigan-based drinking water engineer.

Not all the communities in GLWA’s territory have lead service lines, but many do, creating what Betanzo called two classes of customers. One in four Metro Detroit households has a lead line and could be at risk, she said.

State compliance data analyzed by Betanzo and reviewed by Planet Detroit showed that in 2025, GLWA communities were the only Michigan water systems with documented lead service lines exceeding the 12 ppb action level.

GLWA increases corrosion control

GLWA’s source and finished water does not contain lead, Terry Daniel, deputy chief operating officer for water and field services for GLWA, said in a statement to Planet Detroit.

In September 2024, GLWA announced an increase in its orthophosphate dosage from 1.2 milligrams per liter to 2.4 mg/L following a multiyear corrosion control study, Daniel said. GLWA increased its use of orthophosphate between October 2024 and February 2025.

The increased corrosion control is intended to provide greater protection and help member communities comply with Michigan’s changing lead action levels and updates to the federal Lead and Copper Rule, Daniel said.

EGLE evaluates and regulates GLWA’s corrosion control, and the utility’s decision to increase orthophosphate was made in consultation with the agency, said EGLE spokesperson Dean.

Water utilities use corrosion control to build a protective layer inside pipes and prevent lead from detaching and entering the water, Danielle Land, a University of Iowa drinking water researcher, told Planet Detroit.

“So long as the water quality and the water chemistry are consistent, we can kind of control what leaches out of the pipes,” Land said.

Effectiveness can decline as water is distributed across a region, influenced by changes in pH or temperature, she said.

GLWA has five drinking water treatment plants across its service area.

Factors such as the age of pipes, the pipe material, and the level of abandonment in a neighborhood can impact the effectiveness of corrosion control, Land said.

“There could be neighborhoods where there’s water sitting in the pipes for longer before it’s being used, and I would expect, therefore, an increase in lead leaching,” she said.

The ongoing replacement of lead service lines itself can contribute to higher lead levels in the short term, Land said.

“When we go in, and we dig up those lines … we’ve physically disturbed that scaling and the minerals on the pipe,” Land said, adding that it could take time for corrosion control to reestablish a protective layer over any remaining lead plumbing.

Betanzo said that at the household level, water usage and the presence of lead fixtures influence how much lead comes out of the faucet.

“The more water that passes through, the more corrosion control is in contact with those leaded materials,” she said, adding that it’s well documented that high water use leads to lower lead levels.

GLWA study calls for higher treatment level

A June 2024 report commissioned by GLWA over lead concentrations stemming from lead service lines found orthophosphate levels of 3 mg/L are optimal for reducing lead releases from lead service lines.

The chemical system capacity at GLWA water treatment plants limits the dose to 2.4 mg/L, according to engineering consulting firm Arcadis. The fact that some communities continued to have exceedances doesn’t necessarily mean that orthophosphate levels above 2.4 mg/L are needed systemwide, said GLWA’s Daniel. He added that drinking water systems are taking relatively few samples, and more data are needed to determine whether there’s a systemwide need to increase corrosion control.

Lead and Copper Rule compliance can be influenced by a variety of local factors, including the utility’s flushing program, the presence of lead pipes, and lead in home plumbing and fixtures, he said.

The design, bidding, construction, and commissioning of capital improvements at GLWA water plants to reach the 3 mg/L corrosion control level could take 5-10 years, the Arcadis study said.

By that time, most or all lead service lines may be removed from the distribution systems of member communities, the report said.

Daniel said that, because community water sampling occurs throughout the year, GLWA hasn’t completed the review necessary to determine whether it will make the capital system improvements needed to increase corrosion control to 3 mg/L.

Betanzo said there are very few opportunities for communities to influence water quality after it leaves the treatment plant. All the exceedances were found in communities with lead service lines, not those that only have lead plumbing and fixtures, she said.

Immediate action needed to address lead, expert says

Although GLWA increased corrosion control dosing between October 2024 and February 2025, eight GLWA communities continued to show exceedances in data reported at the end of 2025.

Cyndi Roper, an advocate with the Natural Resources Defense Council’s Safe Water Initiative, said more immediate action is needed. She is calling for the distribution of water filters in communities with elevated lead levels.

“There should be an all-hands-on-deck response to educating people about the fact that there is lead in their drinking water,” she said.

GLWA declined to say whether it would help supply water filters or conduct outreach in communities with lead level exceedances.

“Each community is responsible for managing and maintaining its local system,” the utility said in a statement.

Lead is a neurotoxin with no safe exposure level. Small amounts can cause learning, behavior, and long-term health problems, with infants, children, and pregnant people facing the greatest risk. Long-term exposure is associated with hypertension, decreased kidney function, and increased risk of heart disease.

Betanzo said residents need to know what steps they can take to protect themselves from lead exposure — and that anyone with a lead service line should use a water filter.

“The messaging continues to come out that it’s isolated, it’s in a few communities, a few homes,” Betanzo said. “That’s not what’s happening here.”

The state recommends that Michigan households use a certified, lead-reducing drinking water filter if your home has or if you are uncertain whether it has one of the following: lead or galvanized plumbing, a lead service line, or old faucets and fittings sold before 2014.

Eligible households can apply for Michigan’s filter support program. Households are eligible if they have a child under 19 on Medicaid or a pregnant Medicaid enrollee, and has — or may have — lead plumbing.

Closer look at Melvindale, Hamtramck, Garden City

In 2019, Melvindale collected samples from 30 sites with known lead service lines, out of approximately 3,828 water customers. The 90th percentile lead level for the sampling set was 370 ppb, indicating that 90% of the data points are smaller and 10% are larger. Nine of the 30 individual tested sites exceeded action levels, the city said in its notification to residents.

The city has an estimated 500 lead service lines and 100 composed of unknown material. Replacements are ongoing, and the city’s 90th percentile lead level dropped to 4 ppb in 2024, according to the city’s water quality report.

In 2025, Melvindale reported a 90th percentile lead level of 1 ppb.

In Hamtramck, the 90th percentile lead level reached 28 ppb in 2018.

Hamtramck has 605 lead service lines and nearly 8,000 lines of unknown material, according to the city’s 2024 water quality report. The city replaced 790 lead lines in 2024.

The city reported a 90th percentile lead level of 13 ppb in 2025, exceeding the state threshold.

Water officials from Hamtramck and Melvindale did not respond to Planet Detroit’s requests for comment regarding the cities’ reported lead levels.

Garden City reported a 90th percentile lead level of 26 ppb in 2019, and additional exceedances of 18 ppb in 2024 and 15 ppb in 2025.

The city collected samples from 62 homes in 2025, and 13 exceeded the 12 ppb level.

The city is working to replace known lead lines as quickly as possible, said Brad Ohman, director of the Garden City Department of Public Works.

Of Garden City’s more than 11,600 service lines, 142 are known lead, and 352 are of unknown material, Ohman said. The city distributed filters in 2019 and has since referred residents to the Wayne County Health Department. EGLE and HUD grants are funding the removal of lead lines.

A statement on the city’s webpage says it has been “very proactive in the replacement of all lead service lines within the city, replacing 424 lines since 2019.”

‘Lead release is sporadic’

Small changes in lead numbers from year to year may not signify much, Betanzo said.

“Lead release is sporadic,” she said. “Even at a home where there’s a high risk of lead in the water, we’re not always going to get that high lead result in the individual sample.”

It would likely require many more samples than are required to comply with Michigan’s rule to reach a statistically significant conclusion about a community’s risk, she said.

For example, Detroit’s 90th percentile lead level fell from 13 ppb in 2024 to 8 ppb in 2025, which could be a result of GLWA increasing corrosion control, Betanzo said.

The Detroit Water and Sewerage Department (DWSD) is required to take 50 lead samples a year, she said. The city has over 80,000 known lead lines.

‘Puzzling’ why more isn’t being done to address lead, expert says

Waiting for a utility to deploy more effective corrosion control to reduce the risk posed by lead service lines is a long-term process, Betanzo said.

Starting in 2021, Michigan mandated that communities replace lead service lines within 20 years. Progress varies by water system, and many are behind on meeting reporting requirements, Planet Detroit previously reported.

Beginning in 2027, water systems must replace lead pipes within 10 years, according to federal Lead and Copper rule revisions.

“One of the key gaps in the Safe Drinking Water Act is that it never really requires public water systems to take direct interventions, even if they have prolonged levels of lead,” said Nick Leonard, executive director at the Great Lakes Environmental Law Center.

The initial response to the lead drinking water crises in Flint and Benton Harbor focused on the lengthy process of lowering lead levels, but water systems aren’t compelled to do much to protect residents in the short term, Leonard said.

EGLE’s Dean said that communities with lead action-level exceedances must notify the public and are subject to an increased monitoring schedule.

Water suppliers are federally required to notify everyone they serve within 24 hours once an exceedance is confirmed.

“Residents of communities that have had exceedances have received lead public education documents at every service connection,” Dean said.

Communities with exceedances that treat their water and have lead service lines are required to increase the state-mandated annual replacement rate for lead service lines from 5% to 7%, the EGLE spokesperson said.

“Currently, there are no requirements for water supplies to provide filters,” Dean said when asked about GLWA communities.

Changes to the federal Lead and Copper Rule set to take effect after Nov. 1, 2027 will require communities with three or more exceedances in a five-year period to offer filters to customers.

Roper, with NRDC, said utilities with exceedances should go door-to-door distributing water filters and educational materials, echoing statements from other experts who emphasize the need to distribute filters as soon as possible.

“It is puzzling why this continues to happen, and why there hasn’t been a more expansive response from EGLE on what is going on in GLWA communities,” Roper said.

The scenario parallels roadblocks advocates faced in Benton Harbor when trying to spur action from regulators, who were focused on adjusting corrosion control, she said. West Michigan’s Benton Harbor, which is not part of GLWA, reported a 90th percentile lead level as high as 32 ppb in 2019, prompting drinking water advocates to successfully petition the EPA to intervene in 2021.

Benton Harbor’s water exceeded 20 ppb for several years in a row.

Detroit, Wayne tout progress on lead service line replacement

DWSD has replaced 16,000 lead service lines since 2018 and plans to replace 3,500 this year, Sam Smalley, the department’s deputy director, said.

In addition to the city’s required lead testing, DWSD offers free water quality testing to all residents with lead service lines.

If a test result exceeds the action level, DWSD provides residents with flushing instructions and an NSF-53-certified water filter designed to remove lead, Smalley said.

DWSD works with the Detroit Health Department to provide blood lead level testing for children under 6, he said.

If a child has an elevated blood lead level and there is a lead service line at the home, DWSD coordinates with the health department to remove the line, Smalley said.

The cause of the elevated blood lead level is usually lead paint, not exposure through drinking water, he said.

The city of Wayne has reported multiple lead exceedances, most recently in 2023, when it notified residents of a 90th percentile lead level of 16 ppb.

Dave Schmidt, assistant director of the city’s Department of Public Works, said Wayne has removed all known lead service lines as of 2025. On Dec. 31, 2025, Wayne’s 90th percentile lead level was 7 ppb — in compliance.

The city received support for its lead line removal from EGLE and EPA grants, Schmidt said.

Wayne is removing galvanized lines that may have been hooked up to lead material, he said.

The city distributed filters to residents around 2020, he said.

Water utilities challenge more stringent lead standards

The final EPA Lead and Copper Rule Improvements issued in 2024 lowers the lead action level to 10 ppb beginning in late 2027.

In 2025, the American Water Works Association, which represents thousands of utilities, GLWA employees, and employees of other Michigan water systems, sued the EPA over the revised rule.

The AWWA argues the rule is “neither feasible nor cost-effective” and, as required by the Safe Drinking Water Act, will impact water system compliance and affordability.

GLWA confirmed to Planet Detroit that it’s an AWWA member. When asked whether the utility supports the lawsuit targeting stricter EPA lead rules, a spokesperson said the lawsuit doesn’t apply to GLWA because it doesn’t have lead in its pipes.

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This story was originally published by Planet Detroit and distributed through a partnership with The Associated Press.