Traces of long-banned pesticides persist in U.S. groundwater including in California, a new U.S. Geological Survey study shows, even as concentrations of most chemicals generally declined.
An analysis of 59 groundwater networks from 1993 to 2023 found only one pesticide — the insecticide DBCP, outlawed since 1977 — exceeded health benchmarks in a Central Valley site in California.
The nonprofit news outlet New Lede reports levels of the remaining 58 old-school chemicals dropped across the networks.
Yet persistent traces remain, particularly in farm regions such as the Midwest, underscoring long-term contamination.
The study coincides with proposed U.S. Geological Survey budget cuts under the Trump administration.
The administration has characterized environmental monitoring as politically driven, while the Office of Management and Budget seeks to slash USGS funding by 38%.
Critics warn reduced funding could cripple the nation’s ability to track water quality and pesticide risks nationwide.
