Project Highlights:
- Over 100 boreholes drilled to delineate lateral and vertical extent of contamination
- Over 240 soil samples collected, and 18 monitoring wells installed
- 3-D density-dependent numerical model simulating groundwater flow and contaminant movement
Project Description:
Human health risk assessments were needed for areas of potential concern at Fort Shafter Flats. The risk assessment results would be used to calculate whether remedial measures were required for any of the sites investigated. An ecological risk evaluation was also required for each site as a means to evaluate the need for preparation of a more comprehensive ecological risk assessment.
Environet collected soil and groundwater samples at the 7 sites, involving over 240 samples from over 100 boreholes, and ensuring an accurate delineation of lateral and vertical extent of contamination. The soil and groundwater samples collected were analyzed for a wide array of chemicals such as VOCs, SVOCs, TPH, PCBs, pesticides, and metals. For each of the 7 sites, a human health risk assessment was prepared.
In addition, a total of 18 monitoring wells were installed. These wells were slug and pump tested to yield hydrologic aquifer data, establishing a regional groundwater gradient. Environet was able to use this information to generate a 3-D density dependent numerical model to simulate the movement of groundwater and dissolved contaminants beneath Fort Shafter.