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F� 2.2 Methodology 1 A geophysical survey using electromagnetic methods (EM) and ground penetrating radar (GPR) was conducted by Norcal Geophysical Consultants, Inc. (Norcal) of Petaluma, California to clear the boring locations from underground ' utilities and to determine whether any USTs exist onsite. Two (2) soil borings were drilled to 41 feet and 46 feet bgs on October 4, 1995. These borings were converted to groundwater monitoring wells MW2 and MW3. Six (6) soil borings were drilled to depths of 15 feet to 35 feet bgs. Three (3) borings (B1, B2, and 134) were drilled in the parking lot area to 25 feet bgs by the Geoprobe method. One boring (B3) was drilled also by Geoprobe to 35 feet bgs. Figure 2 (Appendix I) shows the locations of the soil borings and the monitoring wells. Two (2) borings (B5 and B6) located in the basement of the building were hand-angered to 15 feet bgs. Soil samples were collected in all soil borings and in the monitoring well borings at 5-foot intervals, starting at the 5-foot depth to final depth. The soil samples were field-screened for volatile organics using a Photovac Microtip 1000 Photo Ionization Detector (PID) calibrated to 100 parts per million (ppm) isobutylene. Soil samples with the highest PID readings in each boring were analyzed for Total Petroleum Hydrocarbons (TPH) as gasoline and diesel and for VOCs, including benzene, toluene, ethylbenzene and xylene (BTEX). S Groundwater was encountered at 30 feet bgs in monitoring well MW2, at 36 feet L�s to monitoring welliW��and in soil boring B3. The groundwater level rose to 27.7 feet bgs in MW2, to 33 feet bgs in MW3 and to 31 feet bgs in boring B3. After 40 hours, the water level in MW2 was measured at 27.29 feet bgs and at ' 26.64 bgs in MW3. The depth to water was measured in the existing well MWI at 27.90 feet bgs. The three (3) monitoring wells were surveyed by a licensed surveyor to determine their spatial relationships and differences in elevation in ' order to calculate the groundwater gradient and to determine the flow direction. 3.0 GENERAL SITE INFORMATION ' 3.1 Site Location ' The subject property is located at the northeast corner of the intersection of El Dorado Street and Channel Street. The site is in a mixed commercial section and civic area in downtown Stockton (see Figure 1, Topography and Site Location ' Map, Appendix I). The subject property consists of a two-story building with a basement and asphalt-paved parking lot. The building is currently used as a school by the Mission Accomplished Bible College Inner City Christian Academy. The school is called the Lighthouse Village. CRC Environmental Risk Management.loc. Project#2100.230-2 American Savings Bank 222 North El Dorado Street November 3. 1995 Stockton,California 3