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SECTION 2 <br />' PROJECT DESCRIPTION <br /> This section describes details of the field and laboratory activities conducted during the soil <br />' and groundwater investigation to include general drilling techniques, soil sampling, <br /> groundwater monitoring well installation, soil and water sample handling, and laboratory <br /> analyses Field work was conducted on July 8, 9, and 10, 1996 and an additional water <br />' sampling event was performed on October 8, 1996 Figure 2 - Site Plan depicts site layout <br /> and Figure 3 - Soil Boring Location Diagram depicts the extent of the former excavation and <br /> location of soil borings and monitoring well Figures 4 and 5 depict geologic cross sections of <br /> the area investigated and reported results of soil sampling <br /> ' 2.1 SOIL INVESTIGATION METHODOLOGY <br /> A subsurface investigation was performed, consisting of drilling activities for soil test borings <br /> and monitoring well installation, soil sampling, and laboratory analysis For this study, five <br /> (5) test borings were drilled at selected locations in order to collect soil samples, observe <br /> general subsurface hydrogeologic conditions, and to install the monitoring well Soil test <br /> ' boring B-1 was advanced to a vertical depth of 30-feet below ground surface (bgs) located near <br /> the eastern extent of the former UST excavation Boring B-2 was also advanced to a vertical <br /> depth of 30-feet bgs located adjacent to the former UST `A' Boring B-3 was advanced at a <br /> M20° angle to a vertical depth of approximately 33-feet bgs and located at the northern extent of <br /> the former excavation near the federal building Boring B-4 was advanced at a 15° angle to a <br /> ' vertical depth of approximately 30-feet bgs located at the western extent of the former <br /> excavation near the underground electrical vault Monitoring well MW-1 was advanced to a <br /> vertical depth of 50-feet bgs located at the center of the former UST excavation Soil samples <br /> ' were obtained from the borings at approximate five-foot depth intervals, including samples at <br /> the soil/water interface and at any change in lithology Following field screening, selected <br /> samples were laboratory tested for chemical constituents Prior to commencement of field <br /> ' activities, a site health and safety plan was prepared detailing potential physical and chemical <br /> hazards, emergency response procedures, and other related topics <br /> ' 2 1 1 Drilling and Sampling Methods <br /> Drilling services were performed by Mitchell Drilling Environmental Corporation of Rancho <br /> Cordova, California (C57 license #672617) A drilling permit (#009746) was obtained from <br /> the EHD and is included as Appendix A <br /> ' Soil borings completed during the present investigation were advanced using a truck-mounted <br /> mobile CME 75 HT drill rig with an 8-inch outside diameter continuous flight hollow-stem <br /> auger Following soil sample collection the boreholes were either sealed with Type 1-11 <br /> Portland neat cement concrete from total depth to surface or were completed as a monitoring <br /> well <br /> 2 <br /> 1 <br />