Client: USACE Alaska
Location: Yakutat, AK
Completion Year: 2020
Scope of Work:
- Remedial Investigation
Brice performed a Remedial Investigation (RI) at former Yakutat Air Base areas of concern (AOCs) E3 – Hospital Loop and M4 – Post Powerhouse, located near Yakutat, Alaska. The purpose of the RI was to delineate the nature and extent of petroleum, oil, and lubricants (POL) contamination in soil and groundwater, and collect the data needed to evaluate human health (HH) and ecological risks to develop a path forward for each site. In addition, the AOC M4 – A.C. 10 KVA Transformer Bank was evaluated to determine the presence or absence of polychlorinated biphenyls (PCBs).
We investigated for contamination resulting from POL sources only, because POL-related contaminants were the only analytes retained as contaminants of potential concern (COPCs) during a previous investigation. All soil and groundwater samples were analyzed for DRO and RRO. Select soil and groundwater samples were analyzed for GRO, POL-related VOCs, and PAHs. Brice investigated the AOC E3 – Hospital Loop Powerhouse and AST and the AOC M4 – Post Powerhouse. In total Brice advanced ~249 UVOST probes for field screening, advanced and sampled ~135 soil borings for confirmation sampling, installed and sampled 8 monitoring wells, and sampled existing monitoring wells. We used the hydrocarbon risk calculator to assess human health risks associated with POL-contaminated sites.
At the AOC M4 – A.C. 10 KVA Transformer Bank, PCBs were sampled in nine composite samples collected from the building foundation beneath the suspected transformer mount, or in surrounding soils.
Brice recommended Cleanup Complete at two features based on the HRC results, further investigation of a third feature to achieve site closure, and no further action at the A.C. 10 KVA Transformer Bank due to no detections.