PFAS Contamination Map: Forever Chemicals in U.S. Drinking Water

What Are PFAS (Forever Chemicals)?

PFAS (per- and polyfluoroalkyl substances) are a group of over 14,000 synthetic chemicals that have been manufactured since the 1940s. They are called "forever chemicals" because their carbon-fluorine bonds are among the strongest in organic chemistry, meaning they do not break down naturally in the environment or in the human body.

PFAS are used in nonstick cookware, water-resistant clothing, food packaging, firefighting foam (AFFF), and hundreds of industrial applications. They enter drinking water through manufacturing discharge, wastewater treatment plants, landfill leachate, and contaminated groundwater near military bases and airports where AFFF was used.

EPA PFAS Limits (2024 MCL Rule)

In April 2024, EPA finalized the first-ever national drinking water standard for PFAS. Public water systems must comply by 2029. The Maximum Contaminant Levels (MCLs) are:

PFAS Health Risks

Decades of epidemiological research link PFAS exposure to serious health effects. The compounds accumulate in blood and organs over years of exposure, even at very low concentrations.

PFAS and Military Bases

Military installations are among the largest sources of PFAS contamination in the United States. For decades, the Department of Defense used aqueous film-forming foam (AFFF) containing PFOS and PFOA for firefighting training and emergency response at air bases, naval stations, and Army facilities. This foam seeped into groundwater, contaminating drinking water supplies for surrounding communities.

This map shows 1,183 DoD installations across the U.S., of which 844 (71%) are within 10 miles of a ZIP code with detected PFAS contamination. The correlation between military base proximity and PFAS detection is one of the strongest predictors of contamination in drinking water.

In 2023, the DoD identified over 700 installations where PFAS has been released. Cleanup efforts are underway at many sites, but contamination plumes can extend miles from the source, affecting private wells and municipal water systems that were never directly associated with military operations.

Where PFAS Has Never Been Tested

Perhaps more concerning than where PFAS has been found is where it has never been looked for. Of the 40,000+ U.S. ZIP codes with public water systems, only 24% have any PFAS monitoring data. That means 30,000+ ZIP codes — serving tens of millions of Americans — have never been tested for forever chemicals.

The EPA's UCMR 5 (Unregulated Contaminant Monitoring Rule) required testing at water systems serving more than 3,300 people between 2023 and 2025, but smaller systems were only sampled on a representative basis. Rural communities, small towns, and areas relying on private wells are disproportionately affected by this testing gap.

States with the worst PFAS testing coverage include Vermont (1%), Mississippi (2%), Nebraska (2%), Montana (2%), and Maine (3%). Toggle the "Testing Gaps" layer on the map above to see which states have the largest blind spots.

PFAS and Superfund Sites

Many of the most severe PFAS contamination zones overlap with EPA Superfund sites — areas so contaminated they require long-term federal cleanup. Military bases, industrial plants, and airports where PFAS-containing firefighting foam was used are common Superfund designations. The map above shows 1,380 Superfund sites near ZIP codes with PFAS detections.

If you live near a Superfund site, your groundwater may be contaminated even if your public water system tests below MCL limits. Private wells near Superfund sites are especially at risk because they are not subject to EPA testing requirements.

How to Protect Yourself

If your ZIP code shows PFAS detections on the map above, consider these steps:

1. Check your water system's latest test results — enter your ZIP code on ZipCheckup to see PFAS data for your area.
2. Install a certified water filter — Reverse osmosis (NSF 58) removes 90%+ of PFAS. Activated carbon filters (NSF 53) reduce some PFAS compounds. See our Water Filter Matcher.
3. Test your water independently — especially if you have a private well. Labs like SimpleLab Tap Score offer PFAS panels for $150–$300.
4. Avoid sources of PFAS exposure — nonstick cookware, microwave popcorn bags, water-resistant clothing, and stain-resistant furniture can contribute to total PFAS body burden.
5. Request your CCR — your water utility must publish an annual Consumer Confidence Report. It may include PFAS test results.

Data Sources and Methodology

This map uses data from three federal databases:

• EPA ECHO (Enforcement and Compliance History Online) — PFAS monitoring data from public water systems, including individual compound concentrations and MCL compliance status.
• EPA Superfund / NPL (National Priorities List) — locations of Superfund cleanup sites, mapped to nearby ZIP codes within 10 miles.
• DoD Base Structure Report FY2024 — locations of 1,183 U.S. military installations with coordinates, cross-referenced with PFAS detection data to identify contamination proximity.

ZIP codes are classified by contamination severity: High (any MCL exceedance), Medium (detected, approaching MCL thresholds), and Low (detected below half of MCL limits). The data covers tests through early 2026 and is updated periodically as EPA releases new monitoring results.