Guam lawmakers press agencies after Dieldrin detections; EPA lifts advisory with conditions

HAGTAN, Guam — Guam lawmakers pressed local and federal partners on Dec. 11 over Dieldrin contamination in parts of the island—s drinking water, while regulators said treatment and monitoring have reduced immediate risks and set out next steps for a wider investigation.

The joint oversight hearing, convened by committees that include transportation, land use and health lawmakers, followed an Oct. 24 session and focused on recent detections and what agencies are doing to protect residents. "Is the water safe to drink?" the chair asked at the start of the hearing, framing the central question that has driven the inquiry.

Guam Waterworks Authority General Manager Miguel Cverdario described operational responses at the highest-risk production well, known as Y-15. "As of December 9, we have 305 applications" for point-of-entry treatment systems for affected households, Cverdario said, and he told lawmakers that interim treatment at Y-15 produced four consecutive weekly non-detect samples in treated water. GWA also distributed 35,116 cases of bottled water to affected residents between Oct. 2 and Nov. 12 at a reported cost of about $250,000.

Guam EPA Administrator Michelle Lastimosa and senior science adviser Captain Elizabeth DeGrange said the agency formally concurred to rescind the do-not-drink-without-treatment advisory for Y-15 on Nov. 13 after the non-detect results and the utility—s mitigation plan. DeGrange said the rescission was coupled…