Regulatory Update: Multi-State Petition Urges USEPA to Add Microplastics to UCMR-6
Authored by: Jon Rohrer, PG, CHg & Rachel Henke
Regulatory action in the United States on microplastics remains limited, despite growing scientific interest in potential human health and ecological impacts. California took an early lead with Senate Bill (SB) 1422, which on June 16, 2020 established the first state-level definition of microplastics and launched a multi-phase program to assess their presence in drinking water. Since that foundational step, however, progress has advanced only intermittently, leaving a significant gap between emerging science and regulatory action.
Several states are now pushing for federal action. On November 26, 2025, Governor Phil Murphy announced that New Jersey, together with six partner states—Delaware, Illinois, Maryland, Wisconsin, Michigan, and Connecticut—formally petitioned the United States Environmental Protection Agency (USEPA) to include microplastics in the next federal Unregulated Contaminant Monitoring Rule (UCMR-6). The coordinated effort by these states encourages the USEPA to collect nationwide data on microplastics, with potential implications for drinking water providers, dischargers, and the broader regulated community.
If approved for inclusion in UCMR-6, public water systems nationwide serving more than 10,000 residents would be required to sample, analyze, and report microplastics findings, creating the first coordinated, nationwide dataset. This information would help the USEPA assess potential exposure to inform regulatory decisions and could lead to the development of enforceable limits or health advisory levels. Before potential federal action, the petition signals that some states may begin pursuing their own policies or monitoring requirements.
Actions to Take Now, Ahead of Potential Microplastics Regulation
- Facilities discharging stormwater or wastewater potentially containing microplastics (or, who are otherwise involved in potential microplastic generation) and facilities supplying drinking water should begin assessing their potential sensitivity/vulnerability to evolving microplastics regulations.
- Microplastics sampling and analytical methods are still evolving, with significant variability in method availability, detection limits, and turnaround times. Understanding sampling and analytical pitfalls, and developing a plan, are key factors for reliable and defensible results.
Need Assistance with Evaluating Risks from Microplastics?
Roux has been closely monitoring microplastics science, policy, sampling, and analytical techniques. We can support clients with:
- Fate and transport assessments,
- Sampling plan development,
- Lab coordination,
- Data interpretation,
- Regulatory strategy,
- Scientific literature interpretation, and
- Risk communication.
Roux works with drinking water providers, industrial facilities, municipalities, and private-sector clients seeking to understand and proactively manage microplastics-related risk. If your organization is planning for future regulatory requirements—or simply needs clarity on where the science and policy landscape is heading—we are here to help. Please complete the brief form, and a member of our team will follow up to discuss your needs.
