Interim Removal Action, VHF Communication System, North Dutch Island, Alaska

Brice performed an interim removal action (IRA) to excavate petroleum-impacted soil and lead-impacted soil from several areas of concern (AOCs), and restored the site to facilitate a No Further Action/Cleanup Complete Determination. We excavated and disposed of approximately 256 cubic yards of petroleum- and lead-contaminated soil offsite. Confirmation soil samples collected from the final excavation limits indicated that concentrations of petroleum constituents were less than the Method Three ACLs approved by the ADEC in the 2016 IRA Work Plan and lead was less than the ADEC Method Two, Over 40-Inch Zone Human Health cleanup level.

We installed four temporary monitoring wells and sampled downgradient of excavation areas. Three surface water samples were also collected downgradient from excavation areas. Subsurface and surface water samples were analyzed for DRO and RRO with and without silica gel cleanup, GRO, BTEX, PAH, and total lead.

Brice recommended no further action to address impacted soil. We also recommended that surface and subsurface water monitoring be conducted to monitor contaminant concentrations; as well as annual review of results to determine whether the North Dutch Island VHF communication station is eligible for site closure and/or institutional controls.

Performance Highlights

• Successfully collaborated with multiple stakeholders and land owners, to complete a time critical project with complex conditions, from demolition and site investigation through site closure within five months of project award, and avoiding mobilization in the following field season, saving at least $300K in costs
• Received ‘EXCEPTIONAL’ past performance rating from the client