Guam's Main Water Supply Contaminated by Dieldrin Amid Ongoing U.S. Military Presence
A well that provides most of Guam's drinking water was found to contain dangerous levels of the banned pesticide dieldrin, sparking health concerns and lawsuits.
In Yigo, Guam's northernmost village, the Y-15 well—responsible for roughly 80% of the island's drinking water—was found to contain dieldrin at levels more than eight times the local cancer-risk threshold. Authorities issued a "do not drink" advisory, installed granular activated carbon filters, and lifted the warning after tests showed no detectable pesticide. The discovery prompted a wave of legal actions, with lawyer Leevin Camacho filing about 800 claims for $167.5 million against the Guam Waterworks Authority and Guam EPA.
While the exact origin of the contamination is still under investigation, the Joint Region Marianas has identified Andersen Air Force Base as a potential source. The episode highlights persistent environmental issues, including PFAS and legacy military waste, that activists say are tied to the U.S. defense buildup on the island.
Why it matters
Contaminated drinking water threatens public health and underscores the environmental impact of the U.S. military in Guam.
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