Guam agencies tell lawmakers they’ve narrowed testing and sought federal probes as dieldrin response continues

Chair opened a continuation of the joint oversight hearing on dieldrin contamination in Guam’s water at 2:04 p.m., saying residents “deserve timely, clear notice and a coordinated response when public health is at risk.”

Agencies told senators they are moving from identification to coordinated response. Brett Raley, assistant general manager for engineering at Guam Waterworks Authority (GWA), said GWA awarded a contract to begin installations of point-of-entry (POE) household treatment systems and that as of Jan. 5 about 313 households had applied for POE installations and 44 had submitted reimbursement requests. He said Y‑15’s interim treatment system has produced non‑detect results for dieldrin at the point of entry since it went online; other well tests from Dec. 18 reported results between 0.08 and 0.19 parts per billion for several wells. GWA said permanent granular activated carbon vessels for Y‑15 have arrived and that construction of permanent systems at three sites is contractually due by summer 2026, with Y‑15 possibly completing earlier.

Captain Elizabeth DeGrange, senior science advisor…