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w THOME od ENVIRONMENTAL of the laboratory analyses indicate an area of elevated concentrations in the soil beneath and immediately adjacent to the former tank location. No significant concentrations were detected in the water samples. However, groundwater had been measured both in the initial nine soil borings and in the three monitoring wells at a depth of approximately 12 feet below grade, but the slotted interval was completed from 20 feet to 35 feet in a possible second deeper water bearing zone. Therefore, these wells cannot be used to properly evaluate the presence of any free product on the aquifer. These well completions also raise questions on the validity of the water measurements and thus the direction of groundwater movement. Additonally, these wells had been positioned anticipating a groundwater gradient toward the southeast. Instead a groundwater gradient toward the east-northeast has been interpreted by CGI. This suggests that none of these wells are properly located to monitor groundwater down gradient from the former tank location. The borings proposed herein will be used to assess soil impaction. The borings will be completed as groundwater monitoring wells which can then be used to estimate aquifer impaction and groundwater gradient. Additionally, these wells can be used as vapor extraction wells. SCOPE OF SERVICES The proposed scope of services for the site assessment have been developed based on our understanding of previous work conducted on the site. Thorne proposes the following scope of services: o Workplan Preparation o Advance Three Soil Borings/Groundwater Monitoring Wells o Collect Continuous Core Samples and Analyze Six Soil Samples and Three Water Samples o Complete Three Monitoring/VES Wells U Monitor Groundwater Elevations for Tidal Effects o Conduct a Vapor Extraction Feasibility Study C Prepare a Report of Findings The following sections represents a brief discussion of each task. 11/89 Y89-199