Guam EPA details new on‑site wastewater rules, sparks debate over 1,000‑foot wellhead setback

The Committee on Land, Environment, Housing, Agriculture, Parks, and Infrastructure heard a detailed presentation May 29 from the Guam Environmental Protection Agency on proposed amendments to Chapter 12 of Title 22, implementing Public Law 37‑105 and addressing on‑site wastewater systems.

Michelle Lasta, administrator of Guam EPA, introduced the presentation and turned the technical briefing over to Peter Bautista, the agency’s chief engineer. Bautista said the rules add permitting for type‑4 nitrogen‑reducing systems (NSF45/NSF245 certified), allow mound systems in exceptional clay or high water‑table sites, and permit holding tanks only in limited circumstances. “Type four systems would provide up to a 50% reduction in nitrate loading onto the aquifer,” Bautista said, describing the agency’s estimate of environmental benefit.

The proposed regulations would also implement wellhead protection measures and a 1,000‑foot setback around production wells, require percolation (perk) tests for all type‑4 and on‑site systems, mandate leak‑proof tank construction aligned with international codes, and create operating permits and mandatory operation‑and‑maintenance contracts (two‑year renewals for type‑4 systems; one‑year renewals for holding tanks). Bautista said installers, O&M providers and operators will need manufacturer authorization and certification and that Guam EPA will publish an approved list on its website.

A witness who testified in the public comment period (referred to in the transcript as Mr. Dus) praised the agency’s work but urged changes to some provisions. He recommended restoring an earlier definition for “type two,” extending permit validity timelines (from 180 days to one year), and questioned the practical effects of a 1,000‑foot setback. “So if you impose this and you won't be able to get a permit,” he said, warning that the larger buffer could render many lots nonconforming and asked the legislature to instead pursue a program to hook unsewered residences to sewer.

Senators pressed EPA staff on implementation details and workload. Senator Sean Gumatau asked how many more buildings have been added since a 2019 Guam Waterworks Authority (GWA) estimate that identified 2,471 unsewered buildings within specified distances of sewer mains and wells. Bautista said Guam EPA processes roughly 1,000 permit applications per year and uses GIS platforms to plan with utility data but did not provide an updated total for unsewered buildings. Bautista also described an online permitting platform (Walter) that staff say has improved review efficiency.

EPA staff and senators also discussed emerging contaminants. Captain Elizabeth Dra, senior science adviser to Guam EPA, cautioned that neither conventional nor type‑4 systems fully address per‑ and polyfluoroalkyl substances (referred to in the transcript as PAS/PFAS). Dra said treatment can remove some compounds but creates disposal challenges for spent treatment media; the agency noted local pilot sampling is underway to quantify PFAS presence in septic waste streams.

The hearing record shows substantive agreement on the need to modernize decades‑old rules, while industry witnesses and some members urged the agency and legislature to pair regulatory changes with investments in sewer extensions and clear timelines for permit processing.

No formal vote or regulatory adoption occurred at the hearing; the committee moved on after questions and public comment. The regulations remain a proposal under the Administrative Adjudication Act process and will proceed through the established review and adoption steps.