EPA proposes adding microplastics, pharmaceuticals to drinking water watch list

The move could eventually lead to new limits on these contaminants for water utilities, though the EPA rarely sets actual regulations from this list.

Apr. 3, 2026 at 2:08pm

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A highly detailed, ghostly X-ray photograph showing the internal molecular structure of a water droplet, with faint traces of microplastic particles and pharmaceutical compounds floating within the translucent liquid.An X-ray view into the unseen contaminants lurking in America's drinking water, as the EPA moves to address growing concerns over microplastics and pharmaceuticals.Boston Today

The Environmental Protection Agency proposed to include microplastics and pharmaceuticals on a list of contaminants in drinking water for the first time, a step that could lead to new limits on those substances for water utilities. The EPA's Contaminant Candidate List identifies contaminants in drinking water not regulated under the Safe Drinking Water Act, and the agency is publishing the draft of the sixth version of the list, which opens a 60-day public comment period.

Why it matters

Studies have looked at the prevalence of microplastics in drinking water and in people's bodies, and doctors and scientists are still assessing what it means in terms of human health threats. There is also growing worry about pharmaceutical drugs that get into the water supply because humans excrete them and conventional wastewater treatment plants fail to remove them. The listing is an important first step, but environmental advocates say the EPA needs to go further to address plastic pollution and chemical contaminants.

The details

The EPA said they are responding to Americans who have worried about plastics and pharmaceuticals in their drinking water, and the move aims to hand a win to Health Secretary Robert F. Kennedy Jr.'s MAHA movement, which has pressured the EPA to further crack down on environmental contaminants. The EPA uses the Contaminant Candidate List to prioritize research, funding and regulatory decision making, but rarely moves pollutants off the list to set limits for how much is allowed in public drinking water. The EPA said in March that it will not develop regulations for any of the nine pollutants from the list it most recently examined.

  • The EPA is publishing the draft of the sixth version of the Contaminant Candidate List, which opens a 60-day public comment period.
  • The EPA expects to finalize the list by mid-November.

The players

Lee Zeldin

EPA Administrator.

Robert F. Kennedy Jr.

Health Secretary and founder of the MAHA movement, which has pressured the EPA to further crack down on environmental contaminants.

Erik Olson

A senior attorney at the Natural Resources Defense Council who works on drinking water protection.

Judith Enck

A former EPA regional administrator who now heads up Beyond Plastics.

Philip Landrigan

Director of the Global Observatory on Planetary Health at Boston College.

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What they’re saying

“I can't think of an issue that hits closer to home for American families than the safety of their drinking water.”

— Lee Zeldin, EPA Administrator

“Including it in the list would be the first step toward eventually regulating microplastics in public water supplies and hopefully this is not the last step.”

— Judith Enck, Former EPA regional administrator, head of Beyond Plastics

“We can't treat what we cannot measure, we cannot regulate what we don't understand. Together, we're going to define the risk, build the tools and act on the evidence regarding microplastics.”

— Robert F. Kennedy Jr., Health Secretary

What’s next

The EPA is opening a 60-day public comment period on the proposed Contaminant Candidate List, and expects to finalize the list by mid-November.

The takeaway

This proposal marks an important first step in addressing the growing concerns over microplastics and pharmaceuticals in drinking water, but environmental advocates say the EPA needs to go further to regulate these contaminants and address the broader issue of plastic pollution. The inclusion on the Contaminant Candidate List is just the start of a long process that rarely leads to actual regulations, underscoring the need for more decisive action from the EPA and policymakers.