Acting Gov. Joshua F. Tenorio declared a state of emergency on Thursday after dangerously high levels of dieldrin, a banned pesticide, were detected in Yigo water wells. The declaration, outlined in Executive Order 2025-06, comes after the Guam Waterworks Authority (GWA) issued a “Do Not Drink Without Treatment” advisory to more than 1,100 customers earlier this month.
Dieldrin, once widely used on crops but banned by the U.S. Environmental Protection Agency in 1987, is classified as a probable carcinogen. Recent testing showed average levels of 1.75 micrograms per liter in Yigo wells between December 2024 and July 2025 — well above the Guam EPA’s interim action level of 0.2 micrograms per liter. Officials warned residents that boiling the water would not make it safe to drink or cook with.
Under the emergency order, GWA is tasked with leading procurement efforts of up to $250,000 for supplies, treatment systems, and safe drinking water. Immediate measures include water distribution to affected households, monthly well testing, and public reporting. GWA is also working to install granulated activated carbon systems at the contaminated wells, with completion expected within a year.
Tenorio said in a Special Address on Dieldrin that the emergency order is meant to expedite remediation while ensuring families have access to safe water. “We must do more,” he stated in the order, directing agencies to enhance monitoring, provide timely information, and coordinate directly with the Yigo Mayor’s Office to support residents during the crisis.