EPA Will Keep Restrictions PFOA, PFOS in Drinking Water and Eliminate Other PFAS Limits

Update 05/19/25

US EPA will reconsider part of a 2024 Rule that created nationally enforceable drinking water standards for five per- and polyfluoroalkyl substances (PFAS), according to a press release from the Agency on May 14, 2025 linked below.

The April 2024 Final Rule created maximum contaminant levels (MCLs) for five PFAS chemicals—PFOA, PFOS, PFNA, PFHxS, and HFPO-DA (i.e., “GenX”). For PFOA and PFOS, the Rule set the MCL at 4 parts per trillion. For the other three substances, the MCL was set at 10 parts per trillion. 

EPA will maintain restrictions put in place for two substances—PFOA and PFOS—and rescind restrictions on the other three substances for reconsideration. The Agency will rethink the hazard determinations for PFNA, PFHxS, and “GenX,” as well as limits in place on mixtures of these three substances with PFBS. 

Compliance Deadline: PFAS in Drinking Water

The 2024 Rule gave public water systems three years to monitor for these substances and required them to notify customers about pollutant levels. EPA addresses the compliance deadline for public water systems in their press release on May 14, 2025, writing: 
 

“EPA plans to develop a rulemaking to provide additional time for compliance, including a proposal to extend the compliance date to 2031. EPA plans to issue a proposed rule this fall and finalize this rule in Spring of 2026."

US EPA. Press Release, EPA Announces It Will Keep Maximum Contaminant Levels for PFOA, PFOS. May 14, 2025.

When the 2024 Rule was finalized, EPA estimated that 6–10% of the 66,000 covered public drinking water systems may have to take action to reduce PFAS to meet new standards.

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Update 4/26/24

EPA Final Rule on PFAS in Drinking Water (April 2024)

On Friday, April 26, US EPA published the Final Rule to the Federal Register. With this Rule, EPA enacts the first national, legally enforceable drinking water standard aimed at protecting communities in the US from exposure to per- and polyfluoroalkyl substances (PFAS). The Final Rule takes effect on June 25, 2024.

The Rule sets limits for five PFAS:

• PFOA
• PFOS 
• PFNA 
• PFHxS
• HFPO-DA (also known as “GenX”)

The Final Rule was published to the Federal Register on April 26, 2024. 

PFAS in Drinking Water & Maximum Contaminant Levels (MCLs)

For two substances—PFOA and PFOS—EPA set a Maximum Contaminant Level Goal (MCLG) of zero. An MCLG is a non-enforceable health-based goal. EPA is setting enforceable Maximum Contaminant Levels (MCLs) at 4.0 parts per trillion for PFOA and PFOS, individually.

For PFNA, PFHxS, and GenX, EPA is setting both MCLGs and MCLs at 10 parts per trillion. EPA is also setting a limit for any mixture of two or more of the following: PFNA, PFHxS, PFBS, and GenX.

Reducing PFAS Exposure in Drinking Water 

EPA says this final rule will reduce PFAS exposure for approximately 100 million people, prevent thousands of deaths, and reduce tens of thousands of serious illnesses.

All public water systems:

• Have three years to complete their initial monitoring for these chemicals.
• Must inform the public of the level of PFAS measured in their drinking water.
• Must implement solutions to reduce PFAS in their drinking water within five years if PFAS is found at levels that exceed these standards.

EPA will host a series of webinars to provide information to the public, communities, and water utilities about the final PFAS drinking water regulation.

EH&S professionals who finish the Complete Environmental Regulations Online Course can identify the regulations that apply to their facility and locate key requirements to achieve compliance with the Clean Air and Clean Water Acts to EPCRA, TSCA, Superfund, and more.

Tags: drinking water, environmental compliance, PFAS