Announcement of Final Regulatory Determinations for Contaminants on the Fifth Drinking Water Contaminant Candidate List

What it does

The U.S. Environmental Protection Agency (EPA) is announcing final regulatory determinations for nine contaminants listed on the fifth Contaminant Candidate List. Specifically, the Agency is making final determinations not to regulate 2-aminotoluene, cylindrospermopsin, ethoprop, microcystins, molybdenum, permethrin, profenofos, tebuconazole, and tribufos. The Safe Drinking Water Act (SDWA) requires the EPA to make regulatory determinations every five years on at least five unregulated contaminants. A regulatory determination is a decision about whether or not to begin the process to propose and promulgate- a national primary drinking water regulation (NPDWR) for an unregulated contaminant.

The Environmental Protection Agency's summary, as published in the Federal Register.

What changed in the regulation

1 part of Title 40 of the Code of Federal Regulations:

40 CFR 141

Compared with

The Environmental Protection Agency has published 245 final rules in 2026 so far, compared with 263 in all of 2025.

Counted by the Tribune from Federal Register records since Jan. 1, 2025.

What happens next and when

For the purpose of judicial review, the determinations not to regulate in this document are issued as of March 19, 2026.

The agency's dates, word for word.

Check it yourself

• The document in the Federal Register
• Docket EPA-HQ-OW-2024-0456 on Regulations.gov
• Title 40 on eCFR

The record as published

Source: the Federal Register (public domain). The document in the Federal Register