EPA Designates Microplastics, Pharmaceuticals as Priority Drinking Water Contaminants Amid Michigan Push for Monitoring

Trump Administration Takes First Step on Microplastics, But Critics Say It Falls Short

By Michigan Capitol Staff

LANSING — The Environmental Protection Agency announced Thursday that it will add microplastics and pharmaceuticals to its list of drinking water contaminants for the first time, a move that could eventually lead to new limits on those substances for water utilities across the country.

However, the announcement stops short of requiring immediate monitoring of the chemicals' presence in water systems — something Michigan Governor Gretchen Whitmer and a host of environmental groups have long urged.

Federal Action on Long-Standing Concerns

EPA Administrator Lee Zeldin made the announcement at an April 2 event at the agency headquarters, stating that designating the pollutants as priority contaminants under the Safe Drinking Water Act will prioritize them for funding, research and potentially future regulation.

"EPA is sending a clear message," Zeldin said. "We will follow the science, we will pursue answers, and we will hold ourselves to the highest standards to protect the health of every American family."

At the same event, HHS Secretary Robert F. Kennedy Jr. announced that his agency is launching a $144 million initiative called Systematic Targeting of MicroPlastics (STOMP) to measure microplastics in the human body and research their effects on health.

"For the first time in the program's history, EPA is designating both microplastics and pharmaceuticals as priority contaminant groups," Zeldin said.

The Michigan Response

While the federal action marks a milestone, Michigan officials and environmental advocates say it doesn't go far enough.

"We really should be taking action to protect people's health," said Sen. Jeff Irwin, D-Ann Arbor, who frequently sponsors legislation related to plastic pollution. "But we expect so little from the Trump administration, even their acknowledgement that we're going to look at this and collect data is probably a good thing."

In December, Governor Whitmer joined six other Democratic governors to petition the EPA for a monitoring requirement, arguing it would "lead to meaningful methods of reducing the risk to the public's health."

The Trump administration is due to publish an updated list of contaminants that require monitoring — known as the Sixth Unregulated Contaminant Monitoring Rule (UCMR 6) — by the end of 2026.

Michigan's Own Testing Initiative

Despite the federal limitations, Michigan is moving ahead with its own testing program.

Michigan will be conducting a pilot to test five different drinking water systems for the contaminants, and for the next three years, will test about 200 of its inland lakes and streams for microplastics, said Art Hirsch, co-founder of the Michigan Microplastics Coalition.

"We're consuming this stuff, and we really don't know what the risk is," Hirsch said.

Hirsch emphasized that vigilance about microplastics' presence in drinking water is not enough. To effectively curb microplastics pollution, he said, governments need to start regulating the plastic supply chain.

"We're never going to get rid of plastics," Hirsch said. "They're too fundamental. The problem is, we make too much."

The Science Behind the Threat

More than 22 million pounds of plastic waste enter the Great Lakes each year, according to environmental groups. Microplastics are tiny plastic fragments of 5 millimeters or less — about the width of a pencil eraser — that have turned up in human breast milk, blood and brain tissue.

They come from litter that breaks down in the environment, fleece clothing that sheds fibers with every wash, car tires that grind away on road surfaces and many other sources.

While research on humans is limited, animal studies have linked microplastics exposure to learning and memory issues, reproductive problems and a host of other concerns.

Pharmaceuticals, meanwhile, range from anti-anxiety drugs to antibiotics and pain relievers that enter water supplies through human waste, improper drug disposal and intensive livestock operations that routinely dose animals with antibiotics and other drugs.

Pharmaceuticals have shown up at sampling sites across the Great Lakes and in the drinking water of tens of millions of U.S. residents. In the environment, they can harm aquatic life and give rise to antibiotic-resistant bacteria.

Industry Pushback

The US chemical industry's main trade group, the American Chemistry Council, says it is in favor of more microplastics research.

"We support science-driven monitoring of microplastics in drinking water and research to better understand potential impacts," Kimberly Wise White, the group's vice president of regulatory and scientific affairs, said in a statement. "People want clear answers on microplastics, and any drinking water monitoring program must address several existing hurdles, including developing clear definitions, ensuring adequate lab capacity, and standardizing sampling and testing methods to be used consistently across the country."

However, environmental groups remain skeptical about whether the EPA will act on the new list, especially given the administration's recent efforts to roll back environmental regulations including drinking water limits on PFAS "forever chemicals."

"There is good reason to be concerned about toxic PFAS and microplastics in drinking water, but the EPA's actions speak louder than its words," Erik D. Olson, senior strategic director of health at the Natural Resources Defense Council, told C&EN.

Olson pointed out that in addition to delaying and attempting to roll back aspects of PFAS regulations, the EPA recently declined to regulate any additional chemicals from its fifth Contaminant Candidate List.

"Just dumping a load of new pollutants into the purgatory of EPA's long list of dangerous chemicals in drinking water without issuing new standards will do nothing to remove toxic chemicals from the tap water in millions of Americans' kitchen sinks," Olson said.

Public Comments Open

The EPA's list is meant to help prioritize research on and funding for those contaminants. Few contaminants from the list have actually been regulated since the program started in 1996, when Congress amended the Safe Drinking Water Act.

The first contaminants to be regulated after appearing on a Contaminant Candidate List were several types of PFAS, in 2024 under the Joe Biden administration.

The draft list, once finalized, will become the sixth Contaminant Candidate List (CCL). It also includes per- and polyfluoroalkyl substances (PFAS) and disinfection by-products, as well as 75 individual chemicals and nine microbes.

Once the new draft list is published in the Federal Register, the government will take public comments for 60 days.

The proposal to designate microplastics and pharmaceuticals as priority contaminants is open for public comments through June 1.

Michigan's Legislative Efforts

Active bills in the Michigan Legislature to phase out microbeads, require drinking water providers to monitor for microplastics and create a statewide microplastics plan are awaiting votes in the state Senate.

Past efforts to let local governments ban plastic bags, expand recycling programs and ban cosmetics and over-the-counter drugs containing plastic microbeads have all stalled.

At the federal level, Congress passed 2015 legislation phasing out personal care products containing plastic microbeads and directed EPA in 2020 to develop a national strategy on plastic pollution.

Several other efforts to rein in plastic use have stalled, while President Trump last year reversed a Biden-era effort to phase out federal use of single-use plastics.

What's Next

The Association of Metropolitan Water Agencies, which represents publicly owned drinking water systems, says in a written statement that the CCL is "an important early step" and that the association "looks forward to reviewing the draft list and welcomes the opportunity to provide feedback to the Agency as it moves forward."

G. Tracy Mehan III, executive director for government affairs at the American Water Works Association, called for lists "commensurate with the funding available for EPA to deploy to advance Safe Drinking Water Act decision-making processes."

As the debate continues, Michigan remains one of the states ahead of the curve in tackling the plastic pollution problem, with its own testing program underway and legislative proposals pending.