At this facility, a Former Waste Disposal and Burn Area consisted of an unlined, approximate 300 square foot area that was used for uncontrolled disposal and burning of trash, solid waste, industrial waste and pipeline fluids for approximately thirty (30) years. No records regarding disposal operations at the site were available.
To define the nature and extent of the waste, a detailed reconnaissance of the area was performed and the area was mapped and photographed in detail. Based on the field survey, two (2) intersecting test pits were excavated to identify the type of wastes present and to allow for collection of soil/waste samples for laboratory analysis. No solid wastes (i.e., drums, trash, etc.) were observed during test pit excavation. PCBs were detected above the action level in one (1) of several soil samples collected from within the area. Based on the small size of the affected area, excavation of soil was selected as the most appropriate remedial alternative.
Soil Removal Action
The remedial action at this site consisted of excavating an area with dimensions of twenty-five (25) feet by fifteen (15) feet by three (3) feet deep to removed impacted soil. During field work, the excavation area was screened with instruments capable of detecting organic vapors. Erosion and sediment (E&S) control measures and an exclusion zone were established, as needed. A total of approximately forty (40) cubic yards of soil were excavated.
During field work, soil samples were collected from the excavation and screened in the field with soil test kits. The test kits include an immunoassay procedure that allows the user to identify soil that contains PCBs greater than a pre-determined action level. After all impacted soil had been removed, based on the field screening, the excavation was backfilled with clean soil.
Five (5) confirmation samples (one (1) from the excavation floor and one (1) from each sidewall) were collected for analysis of PCBs at an off-site laboratory. All results were less than applicable action levels and no further action was required.
By using immunoassay kits to field screen soils, the volume of excavated soil was limited, which significantly reduced waste disposal costs.
Use of the immunoassay kits also allowed for the soil excavation to be completed during one (1) mobilization, which fixed project mobilization costs and allowed for adherence to a tight project schedule.