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. 24 March 2000 AGE-NC Project No 97-0141 Page 3 of 9 Furthermore, based on the General Soil Map from the San Joaquin County Soil Survey, published by the United States Department of Agriculture Soil Conservation Service in 1992, the site area is withm the Jackson-Hallenbeck-Stockton (JHS) association The JHS soils are located within basins, and generally consist of moderate to poorly drained fine textured soils The soils are generally derived from both marine and non-marine sediment, and are generally formed in alluvium derived from mixed rock sources 2 4 GROUND WATER DEPTH AND GRADIENT According to the map titled Lines Of Equal Depth Of Water Wells-Fall 1998, published by the San Joaquin County Flood Control and Water Conservation District,the estimated depth to ground water at the property is approximately 20 feet below surface grade (bsg) During the most recent monitoring event in October 1999, ground water depth was approximately 19 feet bsg During past monitoring events at the site, ground water flow direction has varied from northwest to northeast . 3.0. SCOPE OF WORK Based on the results of previous investigations and collection of ground water samples,hydrocarbon- impacted soil and ground water has not been delineated at the site Impacted soil has not been delineated south and southeast of the former UST area nor vertically at the site, the dissolved ground water plume has not been delineated to the north and east AGE proposes to drill, install and sample three ground water monitoring wells to evaluate the lateral and vertical extent of petroleum hydrocarbon-impacted soil and ground water One well will be installed near the former UST excavation, to replace "drowned" well MW-1 The pilot boring for this well will be advanced vertically until no field indication of hydrocarbon impaction is present A second well will be installed southeast of MW-1, along the east side of the shop area A third well will be installed between existing"drowned" wells MW-4 and MW-5 Proposed well locations are included on Figure 2 A sensitive receptor survey will also be performed to identify nearby domestic, agricultural, municipal or private wells that could be impacted by dissolved hydrocarbons from the site The assessment will consist of the following tasks • Permitting and pre-field work activities, • Soil sample collection and analysis, Advanced GeoEnvironmental,Inc