EPA Targets Microplastics and Pharmaceuticals in New Drinking Water Watch List
In a landmark move to address emerging public health threats, the U.S. Environmental Protection Agency (EPA) has announced a coordinated effort to tackle microplastics and pharmaceutical contamination in American drinking water. On April 2, 2026, EPA Administrator Lee Zeldin and U.S. Department of Health and Human Services (HHS) Secretary Robert F. Kennedy Jr. Unveiled the draft Sixth Contaminant Candidate List (CCL 6), marking the first time the agency has designated microplastics and pharmaceuticals as priority contaminant groups.
This initiative is part of a broader commitment to “Produce America Healthy Again,” aiming to identify hidden contaminants that could pose long-term risks to the population. By adding these substances to the CCL, the EPA is prioritizing funding and laying the groundwork for potential future regulations.
What is the Contaminant Candidate List (CCL)?
The Contaminant Candidate List is a critical tool used by the EPA under the Safe Drinking Water Act (SDWA). The SDWA is the primary federal law protecting drinking water quality, authorizing the EPA to set limits on harmful contaminants in public water systems.
By law, the EPA must publish an updated CCL every five years. This list identifies emerging contaminants that aren’t currently subject to national primary drinking water regulations but are known or anticipated to be present in public water systems. Whereas the CCL itself doesn’t impose immediate requirements on water systems, it drives essential research into health impacts, occurrence data, and risk levels to inform future regulatory decisions.
The “War” on Microplastics and Pharmaceuticals
The inclusion of microplastics and pharmaceuticals in CCL 6 represents a historic shift in the EPA’s approach to water safety. Secretary RFK Jr. Has described this action as “declaring a war” on microplastics, which are tiny plastic particles measuring less than five millimeters in size.
These particles are ubiquitous in the environment and easily ingested by humans. Because they can persist for hundreds or thousands of years, there are growing concerns that they may build up in human organs, including the hearts and brains, potentially causing significant damage. However, because this is the first time microplastics have been included on the CCL, the EPA noted that significant data gaps remain regarding detection methods and specific human health impacts.
Similarly, pharmaceuticals are now being tracked as a group for the first time, acknowledging the need to understand how medicinal residues in the water supply affect public health.
Other Contaminants Included in CCL 6
While microplastics and pharmaceuticals are the newest priority groups, CCL 6 addresses a wide array of other potential hazards:
- PFAS: Per- and polyfluoroalkyl substances are listed as a class. The EPA is using a broad definition for PFAS, consistent with the reporting rules under the Toxic Substances Control Act.
- Disinfection Byproducts: These are also listed as a class for monitoring.
- Individual Chemicals: The list includes 75 specific chemicals of concern.
- Microbes: Nine different microbes that may be present in public drinking water systems are included.
while PFAS have been on CCL lists since 2009, the current administration’s EPA previously rolled back legally enforceable maximum limits for PFAS that had been finalized in April 2024 under the Biden Administration, as reported by Food Safety.
Timeline and Next Steps
The release of the draft CCL 6 is the beginning of a rigorous review process. The EPA is now holding a 60-day public comment period, allowing stakeholders to submit feedback via docket number EPA-HQ-OW-2022-0946 at regulations.gov.
Before the list is finalized, the EPA will consult with its independent Science Advisory Board. The final version of the Sixth Contaminant Candidate List is expected to be signed by November 17, 2026.
Key Takeaways: EPA CCL 6 Update
| Feature | Details |
|---|---|
| New Priority Groups | Microplastics (< 5mm) and Pharmaceuticals |
| Other Listed Hazards | PFAS, disinfection byproducts, 75 chemicals, and 9 microbes |
| Regulatory Impact | No immediate requirements; used to prioritize research and future regulation |
| Final Deadline | Expected signing by November 17, 2026 |
Frequently Asked Questions
Does the CCL 6 mean my drinking water is currently unsafe?
Not necessarily. The CCL is a “watch list” used to identify contaminants that may pose a risk. Listing a contaminant on the CCL does not mean it is present in your specific water system or that it currently exceeds safe levels; rather, it means the EPA believes more research is needed to determine if regulation is necessary.
What are microplastics and why are they a concern?
Microplastics are plastic fragments smaller than 5 mm. They are a concern because of their persistence in the environment and the potential for them to accumulate in human tissues, including the brain and heart.
How can the public participate in this process?
The EPA has opened a 60-day public comment period. Citizens and stakeholders can provide input on the draft CCL 6 through the official regulations.gov portal using docket number EPA-HQ-OW-2022-0946.