A new legal petition filed by more than 170 top environmental groups demands that the Environmental Protection Agency (EPA) begin monitoring for microplastics in drinking water, an essential first step to reining in pollution viewed as one of the nation’s most pressing public health threats.
The scale of microplastic water pollution, the extent to which the substance is lodged throughout human bodies, and the many health implications have come into sharp focus in recent years, but the EPA still has not taken meaningful action, public health advocates say.
The petition pushes the agency to begin monitoring microplastics as an emerging contaminant under the Safe Drinking Water Act in 2026.
“The EPA has been thinking about it, but they have not been acting, and the goal here is to get them to act,” said Erin Doran, a senior attorney at Food & Water Watch, one of the petitioners.
Microplastics are microscopic bits of plastics that are either intentionally added to products or shed from larger products containing plastic, from clothing to tires to cookware.
The substance has been found in the clouds, atop Mount Everest, in deep ocean trenches and in the Arctic. It can contain any number of 20,000 plastic chemicals, and often is attached to highly toxic human-made compounds – like PFAS, bisphenol and phthalates – linked to cancer, neurotoxicity, hormone disruption or developmental toxicity.
Microplastics have been found to cross the brain and placental barriers, and those who have them in their heart tissue are twice as likely to have a heart attack or stroke during the next several years.
Independent testing has found them in virtually all drinking water samples tested, and other research estimated the average person ingests about 4,000 particles in drinking water annually.
California last year became the first state to start monitoring for the substance.
So far, the EPA has only identified the Safe Drinking Water Act’s Unregulated Contaminant Monitoring Rule as a potential mechanism for monitoring microplastics instead of committing to tracking them, Doran said.
The law requires the EPA to begin monitoring for a new set of emerging contaminants, such as microplastics, every five years. The proposed list will be assembled in the coming year, and a final group of chemicals to monitor will be published in early 2026.
The agency has also opened conversations with “stakeholders” about the rule, Doran said, but it has not indicated it will include the substance in the upcoming monitoring program.
“The importance of acting now … is because it happens in five-year cycles, and those delays could cascade down the line,” Doran said.
Though the process is moving forward, the incoming Trump administration will have final say over the monitoring list. Trump’s allies involved with environmental issues, including those in the chemical industry, leadership in Congress and water utilities, have said they want to rewrite the Safe Drinking Water Act, which would probably make it more difficult to regulate new pollutants, such as microplastics, in water.
If the EPA does not include microplastics in the next batch of emerging contaminants, the environmental groups can sue and ask a court to order it.
