PFAS Was Detected in 15% of Public Water Systems Tested

Across 473 public water systems tested in Indiana over three years, PFAS was detected in 15.4% of treated drinking water. That includes water that had already been treated. A 2026 study in Environmental Research assessed PFAS across every compartment of an entire US state: water, air, fish, and human exposure. The picture it reveals is everywhere-at-once contamination.

What They Found

The study covered Indiana, a state with mixed industrial, urban, and agricultural land use, making it a representative cross-section of middle America. Key findings: PFAS detected in 15.4% of drinking water systems, with 1.9% exceeding proposed EPA maximum contaminant levels. Larger water systems and areas with higher proportions of minority residents were more likely to report detections.

Fish monitoring across the state (940 samples from 44 species) showed substantial bioaccumulation of PFAS. Atmospheric deposition brought both legacy PFAS (like PFOA and PFOS) and newer ultra-short-chain compounds into the state's environment from industrial sources. PFAS contamination wasn't isolated to one source. It's coming from multiple directions at once.

What You Can Do About Water Exposure

If PFAS is in 15% of treated water systems in one representative state, it's reasonable to assume it's widespread nationally. The most effective home filtration methods for PFAS are reverse osmosis and activated carbon block filters. Not all pitcher filters remove PFAS; check the specific certification.

While you can't fix the water supply, you can filter it at the tap and reduce other PFAS sources in your home: nonstick cookware that off-gases PFAS during cooking, stain-resistant furniture and carpet treatments, and waterproof clothing. Browse non-toxic home essentials and non-toxic kitchen alternatives that don't add to your daily PFAS load.

Source: Sepúlveda MS, Brown L, Capozzi SL, Cullom SC, Dick JE (2026). Environ Res.