Guam EPA Soliciting Marine and Surface Water Quality Data Collected January 1, 2021 — December 31, 2025
January 29, 2026 — The Guam Environmental Protection Agency invites the public and all parties interested in fresh and marine surface water quality to share available water quality data collected during the years from January 1, 2021 to December 31, 2025. The Clean Water Act (CWA) requires Guam to provide every two years an assessment of the quality of all its fresh and marine surface waters [section 305(b)] and a list of such waters that are impaired or threatened [section 303(d)]. Guam EPA welcomes any water quality data collected through projects or monitoring and assessment activities performed on Guam’s marine and surface water bodies.
Guam Water Quality Standards (GWQS) surface freshwater category includes waters that flow continuously over land surfaces in a defined channel or bed, such as streams and rivers; standing water in basins, such as wetlands, marshes, swamps, ponds, sinkholes, ponding basins, impoundments, and reservoirs, either natural or manmade; all waters flowing over the land as runoff, or as runoff confined to channels with intermittent flow. Guam’s inventory of fresh and marine surface waterbodies includes rivers and streams, marine bays, marine recreational/coastal waters (beaches) and wetlands.
If you or your organization have studied any of the above surface waters and marine waters or have conducted monitoring or assessment of a specific Guam waterbody, Guam EPA wants to review your data!
Interested parties who wish to share their data are urged to submit them to Guam EPA no later than 5:00 p.m. ChST on Friday, February 13, 2026. Surface and marine water quality data must be submitted electronically (i.e., thumb drive, CD, email) and may be mailed or hand delivered to Guam EPA’s main office at 17-3304 Mariner Avenue, Tiyan, Barrigada, Guam 96913. Email submissions may be sent to margaret.aguilar@epa.guam.gov. No fax submittals will be accepted.
Guam’s list of water bodies and the 2022-2024 303(d) list of impaired waters may be viewed below or at https://epa.guam.gov/emas/. Email inquiries to margaret.aguilar@epa.guam.gov or call (671)588-4787.
