Remedial Investigation, Marine Corps Logistics Base Barstow, CA
|OTIE conducted supplemental remedial investigation (RI), screening level ecological risk assessment (SLERA), and updated/new baseline human health risk assessments (HHRAs) at a former equipment storage/skeet and trap range. OTIE designed and implemented the first multi-increment (MI) sampling program in California gaining regulatory approval through intensive negotiations, trainings, and site meetings. The MI approach was selected as the most cost effective solution for characterization of the 17-acre site with scattered lead shot and trap debris over rugged terrain.
OTIE subdivided the 17-acre skeet and trap range site into 10 decision units (DUs) to achieve consistent site characteristics. The MI sampling reduced the inherent error resulting from heterogeneous distribution of particulate source material (lead shot, target fragments). OTIE developed a flexible work plan to address eight data quality objectives (DQOs); implementation of the sampling plan was successful in providing input data for all eight DQO decisions.
With the MI sampling, coupled with vertical characterization sampling, OTIE completed delineation of vertical and horizontal extent of soil contamination to support human health and ecological risk assessment, off-site transport of contaminants, and feasibility study requirements in one mobilization, thereby achieving cost savings to the Navy of approximately $165,000. No further investigation of this CAOC was recommended. We also performed baseline Human Health Risk Assessment to evaluate exposure risks for workers and child/adult trespassers for the current land use scenario. We determined that the presence of lead shot would cause failure of a hypothetical residential land use scenario. We also performed a Screening-Level Ecological Risk Assessment with recommendations for additional phases of ERA.
|Client Name: NAVFAC Southwest
Location: MCLB Barstow, CA
Contract Value: $600K