USGS Closed Population Fence Repair
Client: United States Geological Survey
IAN Corporation successfully completed the refurbishment of the USGS Closed Population (CP) facility barrier located at Northwest Field North on Andersen Air Force Base, Guam. This 5-hectare site, enclosed by a specialized two-way barrier, plays a critical role in preventing the emigration and immigration of invasive brown treesnakes (Boiga irregularis), supporting long-term research and control efforts. The original fence, constructed in 2004, consisted of a 1.5-meter-high chain-link fence over a concrete footer, covered with ¼-inch metal mesh featuring outward bulges to prevent snake climbing. Despite careful maintenance, the mesh had deteriorated due to Guam’s harsh environmental conditions, particularly salt spray, necessitating full replacement to preserve the site’s integrity.
To carry out the necessary upgrades, IAN Corporation first constructed a temporary containment barrier using plywood and erosion cloth to maintain security during the project. The entrance ramp was disassembled to allow full access to the perimeter fencing. The team then removed the rusted mesh overcoat and applied rust control paint to the underlying chain-link structure to prevent further corrosion. A new metal mesh overcoat was installed, replicating the original anti-climb design to ensure continued containment of brown treesnakes. Finally, the entrance ramp was reassembled, restoring full operational access to the facility.
This work reaffirms the strategic importance of the CP site and reflects a significant military investment in maintaining its functionality for invasive species management and ecological research.
