Location:
Earth Tech completed site investigation, remedial process optimization (RPO) and site cleanup activities to demilitarize the Arctic Surplus Salvage Yard, a privately owned salvage yard near Fairbanks, Alaska. The 24.5-acre site had been used to store, salvage, reclaim and dispose of material mainly from the sale of surplus goods from local military bases. Battery processing and transformer scrapping activities contributed significantly to site contamination. Over 50,000 cubic yards of tracked vehicles, trucks, airplane parts, and metal scrap were found throughout the site.
Earth Tech evaluated remediation processes required to improve risk control effectiveness, accelerate site cleanup time and minimize remediation costs. Earth Tech staff analyzed existing data from the site and evaluated various mix ratios to determine the optimum stabilization mix for the site soils. Additional sampling was completed to confirm the extent of lead and PCB contamination and over 100,000 units of potential OE materials on site were identified, including rockets, launchers, casings, arms, boxes and primers.
Earth Tech’s remediation services included removal and decontamination of non-OE scrap for each grid requiring PCB and/or lead remediation; excavation of soils in 6-inch layers with each grid, followed by stabilization of soils and collection of post-treatment samples to determine placement of the soils into the on-site landfill. Stabilized soils were placed in a new landfill, situated to overlap the existing former military landfill. Earth Tech collected and analyzed confirmatory samples from each landfill cell and then installed a GCL-based cover system for new landfill capping of the military landfill.
Through the use of RPO, Earth Tech determined the actual costs for remedial action and long-term monitoring over 5 years to be only 16% of what was originally anticipated; and, if disposal of the OE materials were included, total project costs were estimated to be only 25% to 30% of the original estimate. The cost reduction is attributed to a more thorough delineation of contaminated areas, a streamlined RD/RA Strategy, elimination of solvent extraction process and treatment/disposal of resultant waste liquids, implementation of solidification for all lead and PCB contaminated soils and a reduction in the field time required for implementation of the remedial action.
To address site safety concerns due to the discovery of OE materials, Earth Tech UXO specialists escorted field crews and/or advised on all scrap movement and subsurface work to identify and separate any materials that were OE-related for further inspection and proper demilitarization. Project safety risks were continually evaluated to determine if additional safeguards would be needed to ensure the health and welfare of project personnel working at the site.
