Client: USACE Alaska
Location: Goose Bay, Alaska
Scope of Work:
- Remedial Investigation
Brice conducted a remedial investigation (RI) at the Acid Storage and Disposal Building (ASB) site located at the Nike Site Bay Formerly Used Defense Site (FUDS) property in Goose Bay, Alaska. The Nike Site Bay facility along with its sister facilities, Nike Site Summit and Nike Site Point, were three Nike-Hercules Missile sites constructed near Anchorage, Alaska in the late 1950s to protect the city and nearby major military installations during the Cold War. Nike Site Bay was operated by the U.S. Army from 1956 to 1979; the facility is now unoccupied.
The project goals were: 1) to delineate the extent and magnitude of chlorinated volatile organic compound (VOC) contamination in the soil and groundwater at the ASB site and to evaluate the risk associated with chlorinated VOCs; and 2) to delineate additional suspected sources of chlorinated VOC contamination using passive soil gas (PSG) sampling; and 3) to evaluate human health and ecological risks associated with CVOC contamination.
To delineate contamination from the ASB source, Brice reviewed historical records, performed field observation and evaluated screening results, and analytical sample results. We also delineated an additional source to the south. For rapid screening of TCE, we used a FROG-4000™ Portable GC PID. However, because the lithology at the site was too dense, and SP16 tooling could not be used obtain groundwater samples without installing permanent monitoring wells. Instead, we installed temporary wells to allow for screening at more limited locations. Site access was challenging requiring us to take an alternative route using ATV trails.
From passive gas sampling (PSG), Brice successfully identified four additional sources of chlorinated VOC contamination at other areas of the site. However, many PSG samplers had to be replaced due to vandalism. Brice recommended additional investigation of these four additional source areas. The risk associated with chlorinated VOCs will be determined based on the extent of contamination, the geology at the site that may hinder or enable the spread of contamination, and the completion of a conceptual site model.
Brice performed a human health risk assessment, including COPC identification, CSM graphic, scoping form updates, and cumulative risk evaluation. We compiled/evaluated historical and new soil and groundwater data for inclusion in the evaluation. We provided recommendations for evaluating each contaminant source in the future. Brice also performed an ecological risk evaluation, with analytical data compared to screening levels in EPA Ecological Risk Assessment Supplemental Guidance for mammal receptors. This comparison was used to update the Ecoscoping form and develop an ecological CSM in accordance with ADEC Ecoscoping Guidance.
- Achieved work objectives with significant change in approach due to changed conditions encountered in the field
- Received “Very Good” CPARS ratings for Management and Quality in the final CPAR dated 7/2/2020