Remediation and Restoration (Remedial Actions): Former Tongue Point Naval Base Landfill, OR

Remedial Action and LNAPL Treatment, Former Tongue Point Naval Base Landfill, OR
Remedial Action and LNAPL Treatment, Former Tongue Point Naval Base Landfill, OROTIE performed a CERCLA landfill closure involving POL and PCBs at the former Naval base in OR under a FFP TO with performance-based milestones. Tasks included preparing design/value engineering documents, performing remedial action, and performing operation and maintenance. We responded to the short, rainy construction season by scheduling and sequencing multiple operations for 54 independent remedial action CLINs for work and cost control, while protecting the uniquely sensitive environment.
The site was an uncontrolled landfill for multiple wastes in an inter-tidal area on a peninsula in the Columbia River. We coordinated with the Oregon Department of Environmental Quality (ODEQ) and obtained permits from NOAA Fisheries Department for “in-water” work that impacted habitat.
The remedial action objective was to prevent PCB-bearing LNAPL leachate seeps from entering the Columbia River. Specific tasks executed included:

    • Installing temporary shoring in an inter-tidal flood zone to contain contaminated sediments during excavation;
    • Installing / operating bermed sediment containment system with a gravel underdrain/sump and 100-gpm dewatering system;
    • Excavating and consolidating 15,000 CYs of sediment;
    • Redesigning, modifying, and operating a 30-gpm LNAPL recovery system consisting of 750 LF of LNAPL collection trenches, five recovery sumps and recharge trenches, an oil/water separator, equalization and product collection tanks, and automated PLC;
    • Redesigning and constructing a 60-mil HDPE geomembrane liner and geocomposite layers;
    • Installing 13 observation wells inside and outside the slurry wall;
    • Abandoning 12 existing wells within the limits of construction; and
    • Restoring the site including wetland rollsod and specialty plantings in the tidally-influenced emergent marsh zones along the river.


Client Name: USACE Seattle District

Location: Former Tongue Point Naval Base, OR

Contract Value: $6.2M

Project Features:

  • Avoided 6 month delay by redesign of slurry wall alignment to be outside of the railroad right-of-way
  • Minimized impact to sensitive intertidal shoreline environment
  • Performed 1 year of LNAPL recovery system O&M with operational “up time” over 95%.