Historical military facilities can sometimes require a cleanup of environmental contamination that was released during legacy operations. The Defense Environmental Restoration Program – Formerly Used Defense Sites (FUDS) program is responsible for this cleanup.
The U.S. Army Corps of Engineers is responsible for the FUDS program and must address more than 532 FUDS properties within its Alaska District. The cleanup requires the district to overcome unique challenges due to complex site conditions and difficult logistics.
Fort Rousseau is one high-priority FUDS in the Alaska district that overcame all challenges and earned the 2020 Secretary of the Army Environmental Award for environmental restoration. Their successful cleanup and restoration included excavation and off-site disposal of contaminated soil from the primary coastal landfill source, located on Virublennoi Island which was actively eroding into the ocean.
Fort Rousseau FUDS was the headquarters for the Sitka Harbor Defenses that, according to historical sources, prepared for but was never engaged in active combat during World War II. Fort Rousseau is located in Sitka, and encompasses 65 acres of land including eight islands connected by a causeway.
The islands, currently designated as the Fort Rousseau Causeway State Historical Site, were chosen as military installation sites during World War II to protect the Naval Air Station on Japonski Island against attacks from the Pacific. Repeated wave scouring and erosion prevented the success of the construction efforts to build an 8,100-foot-long, concrete-capped causeway that would connect the island chain to Japonski Island for road access and for use as a utility conduit.
The Fort Rousseau FUDS project completed the remediation of all contaminated soil identified in a decision document approved in August 2016 by the Alaska Department of Environmental Conservation.
“Because of the extremely high mobilization costs in Alaska, remedial actions must be as efficient as possible to limit cost growth and achieve program objectives in a reasonable timeframe. The lessons learned at Fort Rousseau will be used at many other sites to lower remediation costs and increase project effectiveness,” said Ken Andraschko, Alaska District’s FUDS program chief.
The site that can only be accessed by marine vessels was successfully excavated, and soil and other wastes were transported to offsite locations. With the removal of 933 tons of hazardous waste, 5,157 tons of non-hazardous waste, 317 pounds of electronic equipment, 168 pounds of broken lead-acid battery plates, and approximately 133 tons of steel—that were later recycled—human health risks and environmental risks were significantly reduced. An on-site, lead-in-soil analysis system was developed, reducing the turnaround time for sample results from one week to 24 hours.
Tidally driven logistics helped to carefully time landfill removal activities to coincide with the lowest high tides of the year—occurring over a limited week-long period. These logistics aided in the success of crucial cleanup work that included the complete removal of contaminated soil down to bedrock from depths that would normally be underwater. This cleanup work was performed during the spring to lower the risk of severe weather that could have spread the contaminated landfill material into the ocean.
A temporary dike was created using large capacity bulk soil bags that were filled with clean gravel and plastic sheeting. At the same time, a permanent breakwater was designed using large rocks from within the landfill excavation to limit future shoreline erosion and to provide protection for the excavation area from storm surges.
Contaminant leakage was avoided by using plastic and felt-lined soil bags during marine barge, railway, and truck transportation to the disposal sites. When the temporary dike was removed, the clean gravel from the bulk bags was used to resurface a hiking trail system that had been damaged by heavy equipment during cleanup activities.
Remote camera monitoring was used to observe the progress of site activities and real-time weather/tidal conditions, 24 hours a day. This monitoring system allowed the state regulator to identify potential concerns and to prevent sediment and pollutants from entering the intertidal area of Sitka Sound. The U.S. Army Corps of Engineers (USACE) project delivery team accessed the camera website to verify site conditions, tidal cycles, marine visibility and weather, construction equipment movement and waste handling.
“USACE worked hard to maintain communications with the landowner and regulatory agency and realized the importance of public participation and interaction throughout this project,” said Andraschko.
The collaboration with stakeholders and the interactions with local organizations enhanced community support and ensured smooth project operations. The project was completed early in the summer, benefitting tourists and local sightseers who can now enjoy the islands’ historical features.