Guam lawmakers debate ADU bill; agencies warn of risks to aquifer, letters added to committee report

Senator Christopher M. Duenas introduced Bill 57-38 COR on the floor, asking that the measure be placed on third reading and describing it as an effort "to strengthen housing options by adding a new sub-article 3 to article 1 of chapter 61, title 21" to authorize accessory dwelling units, or ADUs, in residential zones.

The bill's author, Senator Christopher M. Duenas, said he and cosponsors modeled the proposal on ADU laws in other jurisdictions and had added technical amendments after receiving late written testimony from regulatory agencies. "It's very durable," Duenas said, and he described multiple changes: clarifying that ADUs must comply with Guam building and utility codes; replacing references to covenants with deeds for land-management filings; and making building permits the controlling permit type for ADU construction.

Why it matters: debate focused on whether the bill would increase housing density over Guam's sole-source aquifer and how to limit contamination risk. Senators and agency witnesses raised concerns about nitrates, PFAS and other contaminants moving from septic systems into the Northern Guam Lens Aquifer (NGLA).

Key provisions and amendments discussed

Duenas read an amendment he proposed that would restrict ADUs on unsewered lots within the groundwater protection zone. Under the amendment as described on the floor, an ADU proposed within the…