Environmental Challenges in Guam: Military Contamination and Remediation

Military operations spanning more than eight decades have left measurable contamination across Guam's land, groundwater, and coastal zones, creating a remediation landscape governed by multiple federal agencies and a distinct legal framework shaped by Guam's territorial status. The U.S. Department of Defense controls approximately 27% of Guam's total land area (U.S. Government Accountability Office), and legacy contamination from World War II ordnance, Cold War-era activities, and ongoing base operations continues to affect civilian communities. This page covers the scope of military-origin contamination, the regulatory and remediation mechanisms in effect, common contamination scenarios, and the jurisdictional boundaries that determine which agency or legal instrument governs a given site.

Definition and scope

Military contamination in Guam refers to the introduction of hazardous substances, unexploded ordnance (UXO), petroleum products, and chemical agents into the environment as a direct result of U.S. military occupation, training activities, or base operations. The contamination is not limited to active installations — it extends to formerly used defense sites (FUDS), a category managed by the U.S. Army Corps of Engineers under the Defense Environmental Restoration Program (DERP), authorized by 10 U.S.C. § 2701.

Guam's environmental governance sits at the intersection of federal environmental statutes — principally the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA, 42 U.S.C. § 9601 et seq.) — and local regulations administered by the Guam Environmental Protection Agency (Guam EPA), established under Guam Public Law 22-52. The island's unincorporated territory status means federal environmental law applies, but the mechanisms for enforcement and funding differ from those available to U.S. states. The broader political and jurisdictional context of Guam's territorial governance is documented across multiple dimensions at the Guam Territory Authority.

Contaminated sites on Guam are distributed across active installations including Naval Base Guam, Andersen Air Force Base, and the former U.S. Naval Air Station Agana, as well as dozens of FUDS parcels mapped by the Army Corps. The Ordot Dump, a federally operated landfill closed in 2011 under a federal consent decree, represents one of the most prominent non-ordnance contamination cases, having accepted military waste for decades before civilian use.

How it works

Remediation of military contamination on Guam proceeds through two primary frameworks depending on site classification:

1. Active installation sites — Remediation is conducted under the Installation Restoration Program (IRP), a component of DERP. The responsible military branch funds and executes cleanup, with Guam EPA providing regulatory oversight and the U.S. Environmental Protection Agency (EPA) Region 9 serving as the lead federal regulator under CERCLA.

2. Formerly used defense sites (FUDS) — The U.S. Army Corps of Engineers, Honolulu District, manages assessment, cleanup planning, and remediation. Property owners and the Government of Guam are recognized stakeholders but do not control cleanup timelines or funding allocations.

Under CERCLA, sites meeting contamination thresholds may be listed on the National Priorities List (NPL). Guam has NPL-listed sites including the Ordot Co-Dump and the Andersen Air Force Base landfill complexes, which subjects them to the structured Remedial Investigation/Feasibility Study (RI/FS) process prior to any remediation action.

UXO remediation follows a separate but parallel track under the Military Munitions Response Program (MMRP), also authorized under DERP. UXO clearance requires licensed explosive ordnance disposal (EOD) contractors operating under Army Corps oversight. Discovery of UXO during civilian construction in Guam is not uncommon — the Army Corps maintains a reporting hotline and a site inventory for FUDS parcels island-wide.

Groundwater contamination from per- and polyfluoroalkyl substances (PFAS), linked to aqueous film-forming foam (AFFF) used at military airfields, has emerged as a distinct remediation category. Andersen Air Force Base has been identified as a source of PFAS contamination affecting the Northern Guam Lens Aquifer, which supplies drinking water to a significant portion of the civilian population. The EPA has established a maximum contaminant level (MCL) of 4 parts per trillion for PFOA and PFOS individually under the National Primary Drinking Water Regulations finalized in 2024 (EPA PFAS National Primary Drinking Water Regulation).

Common scenarios

Contamination scenarios encountered in Guam's military remediation landscape fall into four primary categories:

• Unexploded ordnance and military debris — WWII-era bombs, shells, and grenades are encountered during land development across the island, particularly in the northern plateau and areas near former Japanese and American defensive positions. The Guam World War II Occupation and Liberation record documents the scale of wartime activity that created this ordnance legacy.
• Petroleum, oils, and lubricants (POL) contamination — Underground storage tank (UST) leaks at active and former bases have introduced hydrocarbons into soil and groundwater, requiring remediation under both CERCLA and the Resource Conservation and Recovery Act (RCRA), 42 U.S.C. § 6901 et seq.
• PFAS groundwater contamination — As noted above, AFFF use at Andersen and Naval Air Station Agana has contaminated portions of Guam's primary freshwater lens.
• Solid and hazardous waste disposal — Military landfills, including the Ordot Dump, accepted mixed waste streams over decades. Post-closure monitoring and leachate control remain ongoing obligations under federal consent decrees.

Decision boundaries

Jurisdictional responsibility for a contaminated site depends on three determining factors: site classification (active installation vs. FUDS), current land ownership, and listing status under CERCLA's NPL.

The Government of Guam has limited enforcement authority over federal military sites — it participates in oversight through Guam EPA but cannot compel cleanup timelines or access federal remediation funding directly. This asymmetry distinguishes Guam's remediation framework from that of U.S. states, which can assert co-regulator authority more forcefully under CERCLA Section 121(f).

The Guam Government Authority provides reference coverage of the Government of Guam's executive and regulatory agencies, including Guam EPA's statutory basis and organizational structure, which is directly relevant to understanding how local environmental oversight interfaces with federal military remediation programs.

The Guam Military Buildup Impact record addresses how the ongoing DoD force realignment from Okinawa — introducing approximately 5,000 Marines to Guam — is generating new environmental review requirements under the National Environmental Policy Act (NEPA) and layering additional PFAS and infrastructure concerns onto existing remediation priorities.

References

• U.S. Army Corps of Engineers — Formerly Used Defense Sites (FUDS) Program
• U.S. Environmental Protection Agency Region 9 — Guam Cleanup Sites
• EPA — PFAS National Primary Drinking Water Regulation (2024)
• Guam Environmental Protection Agency (Guam EPA)
• U.S. Government Accountability Office — Defense Infrastructure Reports
• 10 U.S.C. § 2701 — Defense Environmental Restoration Program
• CERCLA (42 U.S.C. § 9601)
• U.S. Army Corps of Engineers, Honolulu District — Environmental Programs