EPA Cracks Down on Perchlorate in Drinking Water
Published Date: 1/6/2026
Proposed Rule
Summary
The EPA is proposing new rules to limit perchlorate in drinking water to keep it safe and healthy for everyone. Water systems will need to test for perchlorate, fix problems if levels are too high, and share info with the public. These changes affect water providers nationwide, with public comments open until March 9, 2026, and could mean some costs but better health protection.
Analyzed Economic Effects
5 provisions identified: 2 benefits, 3 costs, 0 mixed.
New perchlorate limits proposed
The EPA proposes a health-based Maximum Contaminant Level Goal (MCLG) for perchlorate of 0.02 mg/L (20 micrograms per liter) and is seeking comment on enforceable Maximum Contaminant Levels (MCLs) of 0.02 mg/L (20 µg/L), 0.04 mg/L (40 µg/L), or 0.08 mg/L (80 µg/L). These standards would apply to public water systems and determine when systems must reduce perchlorate in drinking water.
New monitoring rules for water systems
The EPA would require community water systems (CWSs) and non-transient non-community water systems (NTNCWSs) to monitor drinking water for perchlorate, with monitoring frequency based on previous results and options to use previously collected data or reduced monitoring if initial samples are low. The proposal includes provisions to automatically reduce monitoring frequency for systems with low or non-detect results.
Required fixes when levels exceed MCL
If a public water system exceeds the perchlorate MCL, the system would need to mitigate the contamination by installing treatment (examples: ion exchange, reverse osmosis, biological treatment), switching to an uncontaminated source, or using certified point-of-use devices for small systems. Systems that exceed the MCL would also be required to report and take actions to come back into compliance.
EPA estimates nationwide costs exceed benefits
The EPA estimates annualized incremental nationwide costs and benefits (2023 dollars) for each MCL option: for a 20 µg/L MCL, annualized cost $16.1 million (3% discount) and monetized benefit $8.3 million (net -$7.8 million); for 40 µg/L, cost $11.2 million and benefit $6.8 million (net -$4.4 million); for 80 µg/L, cost $8.6 million and benefit $5.3 million (net -$3.3 million). The Agency concluded that monetized benefits do not justify the costs for any of the proposed MCLs.
Public notice and consumer reporting rules
Water systems would have to provide Consumer Confidence Reports and Tier 1 public notifications to customers when perchlorate levels exceed the MCL, with Tier 1 notification required for an exceedance because of the effect on the most sensitive population identified. These notices would inform customers about perchlorate detections and any required actions.
Your PRIA Score
Personalized for You
How does this regulation affect your finances?
Sign up for a PRIA Policy Scan to see your personalized alignment score for this federal register document and every other regulation we track. We analyze your financial profile against policy provisions to show you exactly what matters to your wallet.
Key Dates
Department and Agencies
Related Federal Register Documents
2026-06275 — Renewable Fuel Standard (RFS) Program: Standards for 2026 and 2027, Partial Waiver of 2025 Cellulosic Biofuel Volume Requirement, and Other Changes
The EPA just set new rules for renewable fuels in 2026 and 2027, including how much biofuel must be used. They’re also easing the 2025 cellulosic biofuel goals because production fell short and dropping renewable electricity as a qualifying fuel. These changes affect fuel producers and sellers, kick in mostly by mid-2026, and aim to keep America’s fuel cleaner and greener without breaking the bank.
2026-05167 — National Emission Standards for Hazardous Air Pollutants: Ethylene Oxide Emissions Standards for Sterilization Facilities Residual Risk and Technology Review Reconsideration
The EPA is proposing changes to rules for sterilization facilities that use ethylene oxide, a chemical that can be harmful if not controlled. They want to remove some strict risk-based limits, fix technical mistakes, and update how facilities prove they’re following the rules. If you run or work with these facilities, get ready for new deadlines and clearer standards by mid-2026, which could affect how you manage emissions and compliance costs.
2026-04646 — Standards of Performance for New Stationary Sources and Emission Guidelines for Existing Sources: Large Municipal Waste Combustors Voluntary Remand Response and Five-Year Review
The EPA is updating pollution rules for big trash-burning plants to cut harmful emissions like lead, mercury, and dioxins. These changes affect both new and existing facilities, tighten limits, remove some loopholes, and improve reporting, all starting May 11, 2026. This update will help clean the air by reducing over 3,200 tons of pollution each year, making communities healthier and safer.
2025-21788 — Oil and Natural Gas Sector Climate Review: Extension of Deadlines in Standards of Performance for New, Reconstructed, and Modified Sources and Emissions Guidelines for Existing Sources
The EPA is giving oil and natural gas companies more time to meet new pollution control rules and report their emissions. Deadlines for fixing leaks, monitoring equipment, and submitting state plans are pushed back to help everyone get ready without rushing. These changes keep the climate goals on track while easing the financial and timing pressure on the industry.
2025-20402 — Updated Definition of “Waters of the United States”
The EPA and Army Corps are updating the rules that decide which waters are protected under the Clean Water Act, following a 2023 Supreme Court decision. This change helps everyone know exactly which waters are covered, making it easier to protect lakes, rivers, and wetlands while respecting state and tribal rights. People and businesses affected should share their thoughts by January 5, 2026, as this update could impact water projects and environmental protections.
2025-19882 — Perfluoroalkyl and Polyfluoroalkyl Substances (PFAS) Data Reporting and Recordkeeping Under the Toxic Substances Control Act (TSCA); Revision to Regulation
The EPA is updating rules for companies that make or import PFAS chemicals, asking them to report certain info about these substances from 2011-2022. The changes add some smart exceptions to ease reporting on things companies probably don’t know, saving time and hassle. Comments on the proposal are open until late December 2025, so affected businesses should get ready to weigh in!
Previous / Next Documents
Previous: 2025-24272 — Restoring Flexibility in the Child Care and Development Fund (CCDF)
The government wants to make it easier and cheaper for states to run child care programs by rolling back some new rules from 2024. Families, child care providers, and states will see changes like no more strict limits on family co-pays and more flexible payment methods for providers. Comments on these changes are open until February 4, 2026, so everyone has a chance to weigh in before the new rules take effect.
Next: 2026-00048 — Safety Zone; West of Cyril E. King Airport, St. Thomas, VI
The Coast Guard wants to create a permanent safety zone in the waters west of Cyril E. King Airport in St. Thomas, USVI, to keep boats and people safe from low-flying planes. This means no one can enter the zone without special permission. If you’re affected, you have until February 6, 2026, to share your thoughts—no fees or costs involved, just safety first!
Take It Personal
Get Your Personalized Policy View
Start a Free Government Policy Watch to see how policy affects your household, then upgrade to PRIA Full Coverage for year-round monitoring.
Already have an account? Sign in