One State Proved PFAS Regulations Work. The Rest Are Still Waiting.

New Jersey's drinking water contains roughly half the PFAS contamination it did before the state imposed enforceable limits on forever chemicals, according to a peer-reviewed Rutgers University study published this month. The research found a 55% reduction in PFAS levels across the state's public water systems since New Jersey became the first state to set maximum contaminant levels for specific PFAS compounds.

The findings land at a moment when federal PFAS protections face uncertainty, and a separate Michigan State University study has linked PFAS exposure to measurably weaker immune responses in adults. Together, the two studies sharpen a question that affects every American on a public water system: does regulation actually work, and what happens where it doesn't exist?

What the Rutgers Researchers Found

New Jersey's Department of Environmental Protection established individual maximum contaminant levels for PFOA, PFOS, and PFNA beginning in 2018, years before any federal standard existed. The Rutgers study tracked PFAS concentrations in public water supplies before and after those limits took effect, measuring a 55% overall decline. The state's early action forced water utilities to install treatment systems, primarily granular activated carbon and ion exchange technologies, capable of reducing PFAS to below the state's thresholds.

The study positions New Jersey as a case study for what happens when a state acts ahead of federal regulators. Most states still have no enforceable PFAS limits of their own, relying instead on federal rules that have faced delays and rollbacks.

Michigan Study Links PFAS in Blood to Weaker Vaccine Response

A second study, published the same week by Michigan State University researchers, strengthens the public health case for reducing PFAS exposure. The MSU team examined associations between serum PFAS concentrations and COVID-19 antibody levels among fully vaccinated adults. Their findings, published in the journal Environmental Research, showed that higher PFAS levels in the blood correlated with lower antibody responses to vaccination.

The implication is direct: PFAS contamination in drinking water doesn't just accumulate in the body. It may actively interfere with the immune system's ability to respond to infection and vaccination. This adds to a growing body of evidence linking PFAS, sometimes called "forever chemicals," to thyroid disease, certain cancers, and developmental harm in children.

Why Most States Lag Behind

The EPA finalized national PFAS drinking water standards in 2024, setting limits of 4 parts per trillion for PFOA and PFOS, but implementation timelines stretch years into the future and recent agency actions have introduced uncertainty about enforcement. Meanwhile, the vast majority of states have not set their own enforceable limits, leaving residents dependent on federal rules that may or may not hold.

For the roughly 176 million Americans whose tap water contains detectable PFAS, according to U.S. Geological Survey estimates, New Jersey's 55% reduction is proof of concept. It also underscores that without local or state-level action, many communities will wait years for comparable protections.

Private Wells and Unregulated States Still Exposed

Even in New Jersey, the study's results apply to public water systems that installed treatment infrastructure. Residents on private wells fall outside those protections entirely. Private wells are not subject to state or federal drinking water standards, meaning homeowners bear full responsibility for testing and treatment. PFAS contamination is colorless, odorless, and tasteless, so there is no way to detect it without laboratory analysis.

For households on public water in states without enforceable PFAS limits, the situation is similar in practice. Utilities have no legal obligation to treat for compounds that aren't regulated, and many don't. Point-of-use filtration remains the most reliable household-level defense, but the type of system matters significantly when it comes to PFAS removal.

What This Means for You

If you're in New Jersey:

• If you're on a public water system, request your utility's most recent Consumer Confidence Report and check for PFOA, PFOS, and PFNA levels against the state's MCLs.
• If you're on a private well, your water is not covered by the state standards that produced the 55% decline. Get a laboratory PFAS test through a state-certified lab to know your baseline.

For general preparedness:

• Check whether your state has set its own enforceable PFAS limits. If it hasn't, your utility may not be required to test for or treat PFAS at all. A home water quality test is the fastest way to find out what's in your tap water.
• If you install a point-of-use filter for PFAS, verify it carries NSF/ANSI 58 (reverse osmosis) or NSF/ANSI 53 (activated carbon) certification specifically for PFOA and PFOS reduction. Generic carbon pitchers are not sufficient for most PFAS compounds.

Filtering PFAS at the Household Level

PFAS molecules are extremely stable, which is precisely why they persist in water supplies and in the human body. Standard carbon pitcher filters reduce some PFAS compounds, but peer-reviewed testing consistently shows that reverse osmosis systems certified to NSF/ANSI 58 achieve the highest removal rates, often exceeding 95% for PFOA and PFOS. Activated carbon block filters certified to NSF/ANSI 53 can also reduce certain PFAS compounds, though performance varies by filter design and water chemistry.

For households concerned about whole-home exposure, including water used for cooking and bathing, a whole house filtration system with granular activated carbon provides a first line of defense, though under-sink reverse osmosis at the drinking water tap remains the most effective final barrier. Our guide to the best countertop reverse osmosis systems covers compact options that require no permanent installation, and our under-sink water filter guide reviews systems that handle higher daily volumes for families.