EPA Adds Microplastics to Drinking Water Watchlist
EPA included microplastics in its draft list of possible drinking water contaminants on April 2, 2026.
Why it matters: New regulatory scrutiny of microplastics could spark drinking water rules impacting compliance deadlines and enforcement risks for companies and utilities. Legal teams advising manufacturers, water providers, and other regulated entities should track these developments to anticipate new obligations and potential liabilities.
- On April 2, 2026, EPA published a draft list adding microplastics as potential drinking water contaminants.
- The draft Contaminant Candidate List 6 (CCL 6) names 75 chemicals, 4 chemical groups, and 9 microbes.
- The list now includes microplastics and per- and polyfluoroalkyl substances (PFAS), raising possible future regulations.
- EPA will accept public comment for 60 days, through June 5, 2026.
The EPA published notice in the Federal Register on April 2, 2026, stating it placed microplastics on its draft Sixth Contaminant Candidate List (CCL 6). This list, updated every five years under the Safe Drinking Water Act (SDWA), informs which contaminants may face national regulations in coming years.
- Microplastics, tiny plastic particles less than 5mm long, appear for the first time in EPA's priority assessment for drinking water contamination risks.
- Per- and polyfluoroalkyl substances (PFAS) — a group of synthetic chemicals known for their persistence in the environment and potential health effects — also feature on CCL 6, continuing recent regulatory momentum.
- The draft list also spotlights pharmaceuticals, expanding regulatory focus on emerging contaminants.
EPA Administrator Lee Zeldin said on April 2, “EPA will follow the science as we protect the health of every American family by ensuring safe drinking water for all.” (EPA news release).
The regulatory process begins with public comment, open through June 5, 2026, after which EPA will review input and consider which contaminants warrant standards-setting. According to the Natural Resources Defense Council (NRDC), companies handling plastic products or packaging should review how the CCL may affect their operations and compliance risks.
The draft CCL 6 includes 75 chemicals, four chemical groups, and nine microbial contaminants. For microplastics, EPA identified four critical data gaps: developing clear definitions, improving detection methods, understanding interactions with other substances, and mapping sources (industry analysis).
Legal teams should note that the CCL process is a precursor to regulation, and new standards could drive stricter reporting and monitoring requirements across multiple industries.
By the numbers:
- 75 chemicals — named in CCL 6 draft, including new additions like microplastics
- 60 days — public comment window on the Federal Register notice (Apr. 2–Jun. 5, 2026)
- 4 — chemical groups listed, including PFAS and microplastics
Yes, but: EPA has yet to propose enforceable limits for microplastics; actual regulatory deadlines may still be years away.
What's next: EPA will review public comments and may finalize the CCL 6 list, moving microplastics closer to formal regulatory oversight.