The Guam Waterworks Authority (GWA) has completed installation of an interim treatment system at well Y-15 in Yigo, marking a key milestone toward lifting the “Do Not Drink without Treatment” advisory issued earlier this year. The system, commissioned on Oct. 10, uses granular activated carbon (GAC) filtration to remove dieldrin and other contaminants from the local water supply.
“With the installation of this treatment system, our community can be assured that the water supply meets all federal and local drinking water standards while we continue working toward our long-term solution for Y-15,” said GWA General Manager Miguel C. Bordallo The Guam Environmental Protection Agency (EPA) will review weekly lab results from the new system, and after four consecutive weeks of satisfactory tests, the advisory could be lifted for affected Santa Rosa/Yigo customers as early as November.
The GAC system represents an interim measure as GWA continues work on a full-scale treatment project, scheduled for completion by summer 2026. The long-term project aims to address dieldrin and other potential contaminants across the island’s water system. In the meantime, GWA will conduct monthly sampling of Y-15 and publish results on its website guamwatersafety.com, which also provides resources and updates on water quality efforts.
In coordination with Guam EPA and the Office of the Governor, GWA has implemented several measures to assist residents, including bottled water distribution at the Yigo Gym, reimbursements for point-of-use filtration systems, and agricultural inspections in the area. Residents with questions about water quality can contact the Guam EPA Community Hotline at (671) 888-4342 or GWA at (671) 647-7800.