Bethel was contracted to perform a tank demolition and contaminated soil removal action and remediation at this Formerly Used Defense Site (FUDS). The purpose of the project is to demolish and dispose of a 1,000,000 gallon underground storage tank (UST) and its associated foundation and piping, remove 60,000 CY of uncontaminated overburden to expose a contaminant mass of approximately 20,000 CY, requiring excavation to depths greater than 50-feet bgs, and install up to 20 groundwater monitoring wells. The contaminant of concern is primarily diesel fuel. Ten acres of landfarm needed to be built and the contaminated soil excavated and treated in landfarm cells until concentrations meet migration to groundwater standards, at which time the treated soil can be used to backfill the excavation. Once the soil is treated, the site will be returned to prior conditions.
Bethel proposed landfarming as a treatment option; a less expensive approach to soil treatment than other conventional soil treatment processes. We subcontracted locally, assuring that local residents benefit from the project, thus developing local support for the project while reducing mobilization and operation costs. When possible, materials were recycled, including the re-use of fencing to surround the excavation and liner material to develop a lined cell for contaminated soil treatment.
Work on this project began in the 2015 field season. HAZWOPER and fall protection training was provided for the local crew. The UST and its associated foundation were demolished and disposed at the local inert waste Monofill. Eight acres of landfarm were developed, overburden was removed, and 9,300 CY of contaminated soil was excavated and staged for spreading in the landfarm cells. Ten monitoring wells were installed at depths up to 50 feet bgs.
The project has so far been executed with no reportable accidents.
Work performed
- USACE/ADEC Plans and Reports
- Demolish/Dispose UST
- Install Groundwater Monitoring Wells
- Soil Excavation
- Develop/Operate Landfarm
- Remote Site Logistics
