# 2025-00133: EPA Decides Nine Unpronounceable Chemicals in Water Are Fine 2025-00133, Announcement of Preliminary Regulatory Determinations for Contaminants on the Fifth Drinking Water Contaminant Candidate List, is a Federal Register notice from an unnamed agency published 2025-01-15, effective 2025-01-15; PRIA reads it as touching household money (as of 2026-06-08). - Canonical: https://policyrisk.com/federal-register/2025-00133 - As of: 2026-06-08 - Plain-text twin of the page above; the HTML and this file carry the same facts. ## Facts - Document number: 2025-00133 - Title: Announcement of Preliminary Regulatory Determinations for Contaminants on the Fifth Drinking Water Contaminant Candidate List - Type: Notice - Agencies: unknown - Citation: unknown - Published: 2025-01-15 - Effective: 2025-01-15 - Comments close: not stated - Significant: no - Touches household money: yes - Regulation identifier numbers: none - Last updated: 2026-06-08 ## In one line EPA Decides Nine Unpronounceable Chemicals in Water Are Fine ## Summary The EPA is deciding whether to regulate certain chemicals found in drinking water from their latest list. They’ve chosen not to regulate nine specific contaminants for now but want your thoughts by March 17, 2025. This affects water providers and communities, helping keep water safe without rushing costly new rules. ## Abstract The Safe Drinking Water Act (SDWA), as amended in 1996, requires that the U.S. Environmental Protection Agency (EPA) determine whether to regulate at least five unregulated contaminants every five years. The decision to regulate or not to regulate a contaminant is known as a regulatory determination. In most cases, the contaminants chosen for regulatory determination are selected from the most recent Contaminant Candidate List (CCL), which the SDWA requires the EPA to publish every five years. This document presents the preliminary regulatory determinations and supporting rationale for contaminants listed on the EPA's fifth CCL (CCL 5). Since the fourth round of regulatory determinations was published in March 2021, the EPA has made determinations to regulate per- and polyfluoroalkyl substances (PFAS), including individual determinations for three PFAS: perfluorononanoic acid (PFNA), perfluorohexanesulfonic acid (PFHxS), hexafluoropropylene oxide dimer acid and its ammonium salt (HFPO-DA, also known as GenX or GenX chemicals); and mixtures including two or more of these three PFAS and perfluorobutanesulfonic acid (PFBS). In April 2024, the agency issued a final National Primary Drinking Water Regulation that includes these four PFAS as well as perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS). In this Federal Register Notice (FRN), the EPA is making preliminary determinations not to regulate nine additional contaminants from CCL 5: 2-aminotoluene, cylindrospermopsin, ethoprop, microcystins, molybdenum, permethrin, profenofos, tebuconazole and tribufos. The EPA requests public comment on these preliminary determinations and other aspects of this FRN. The EPA also presents updates on additional contaminants from CCL 5, as well as on some of those that have been considered in previous rounds of regulatory determinations and for which the EPA has not yet made a regulatory determination. The agency is also presenting and requesting comment on the process and analyses used for this round of regulatory determinations (i.e., RD 5), the supporting information, and the rationale used to make these preliminary decisions. ## Effects PRIA read - EPA Says It Will Not Regulate Nine Chemicals: mixed, medium. The EPA published preliminary decisions not to regulate nine contaminants from the Fifth Contaminant Candidate List: 2-aminotoluene, cylindrospermopsin, ethoprop, microcystins, molybdenum, permethrin, profenofos, tebuconazole and tribufos. The agency is asking for public comment on those preliminar… - No New Requirements Now for Water Systems: mixed, medium. The EPA states that neither these preliminary regulatory determinations nor the final regulatory determinations, when published, impose any requirements on anyone. That means public water systems and other parties are not being required by this action to implement new regulatory controls as part of… - If EPA Later Regulates, Timelines Apply: mixed, low. The notice explains statutory timelines: if the EPA makes a final determination to regulate a contaminant, the agency must publish a proposed Maximum Contaminant Level Goal (MCLG) and a proposed National Primary Drinking Water Regulation (NPDWR) within 24 months, and publish a final MCLG and NPDWR… - EPA Continues Evaluations of Other Contaminants: mixed, medium. The EPA is presenting updates and continuing evaluation for additional CCL 5 chemicals and some contaminants previously considered, including 1,2,3-trichloropropane, 1,4-dioxane, manganese, quinoline and strontium. Those ongoing evaluations may inform future regulatory determinations. ## Related documents - [2026-20724](https://policyrisk.com/federal-register/2026-20724): Notice of Intent To Prepare a Supplemental Environmental Impact Statement for the Sentinel Deployment and Minuteman III Decommissioning and…, 2026-10-09 - [2026-20771](https://policyrisk.com/federal-register/2026-20771): Center for Scientific Review; Notice of Closed Meetings, 2026-10-09 - [2026-20708](https://policyrisk.com/federal-register/2026-20708): Self-Regulatory Organizations; Investors Exchange LLC; Notice of Filing and Immediate Effectiveness of Proposed Rule Change Pursuant to IEX…, 2026-10-09 - [2026-20710](https://policyrisk.com/federal-register/2026-20710): Self-Regulatory Organizations; Investors Exchange LLC; Notice of Filing and Immediate Effectiveness of Proposed Rule Change Pursuant to IEX…, 2026-10-09 - [2026-20779](https://policyrisk.com/federal-register/2026-20779): Passenger Vehicle and Light Truck Tires From Thailand: Preliminary Results and Rescission, in Part, of Antidumping Duty Administrative Revi…, 2026-10-09 - [2026-20763](https://policyrisk.com/federal-register/2026-20763): National Environmental Policy Act Implementing Procedures: Wintertime Oil and Gas Exploration in the National Petroleum Reserve in Alaska C…, 2026-10-09 ## Sources - [2025-00133 on federalregister.gov](https://www.federalregister.gov/documents/2025/01/15/2025-00133/announcement-of-preliminary-regulatory-determinations-for-contaminants-on-the-fifth-drinking-water) - [2025-00133 as published (PDF)](https://www.govinfo.gov/content/pkg/FR-2025-01-15/pdf/2025-00133.pdf) ## Related - [Previous: 2024-31058, Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2023](https://policyrisk.com/federal-register/2024-31058) - [Next: 2025-00416, Request for Public Comments on Reports on Alcoholic Beverages and Health To Inf…](https://policyrisk.com/federal-register/2025-00416) - [All Federal Register documents](https://policyrisk.com/federal-register) Source: PRIA, https://policyrisk.com/federal-register/2025-00133 (as of 2026-06-08).