In April 2024, the EPA finalized the first National Primary Drinking Water Regulation for PFAS. The rule sets MCLs for six PFAS compounds and requires all public water systems to begin monitoring. For small and mid-sized systems, the compliance timeline is tighter than it looks.

PFAS MCLs That Apply to Your System

PFOA: 4 ppt. PFOS: 4 ppt. PFHxS, PFNA, HFPO-DA (GenX): 10 ppt each. These MCLs apply to all community water systems and non-transient non-community water systems regardless of size.

See exactly what your system is up against

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Initial Monitoring Deadline: April 2027

Systems must complete initial monitoring within 3 years of the rule effective date. Systems with no prior PFAS monitoring data must begin sampling immediately and submit results to their primacy agency. Quarterly monitoring is required if PFAS are detected at or near the MCL.

What Happens If PFAS Are Detected Above the MCL

Public notification within 30 days. Reporting to the state primacy agency. Quarterly monitoring. A compliance solution — typically treatment or source water changes — within 5 years.

Why Small Systems Are at Higher Risk

Small systems often rely on groundwater that has had less historical monitoring. Systems that have never tested for PFAS have no idea whether they are compliant. A violation discovered by the state rather than proactive monitoring carries the full weight of public notification and enforcement.

How Orevant Tracks PFAS for Your System

Orevant maps your PFAS monitoring obligations based on your PWSID, source type, primacy state, and existing SDWIS violation history. Orevant alerts you when regulatory PFAS updates affect your system specifically.

Check My System PFAS Status — Free at orevant.com

FAQ

Does the PFAS rule apply to my small system?

Yes, if you are a community water system or non-transient non-community water system. System size does not exempt you from the MCLs.

What if we already did UCMR 5 monitoring?

UCMR 5 data may satisfy the initial monitoring requirement. Your primacy state agency will confirm. Orevant flags this in the compliance scan.

How long do we have to achieve compliance if we exceed the MCL?

Up to 5 years from the MCL effective date, but public notification and reporting obligations begin the moment a violation is confirmed.