Research

Research & data studies

Original analyses of U.S. drinking-water data, built on EPA & USGS public records. Free to read and cite.

Data study · July 2026 PFAS in America's tap water: systems reporting levels above the EPA's new limits Water systems serving roughly 80 million people reported a PFAS “forever chemical” above an EPA limit in the latest national testing. See the ranked list, by system and state. Read the study →