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3.3.1 Geophysical Clearance of Drill Sites <br /> A ground conductivity instrument (Geonics, EM-31DL) and Geometries (G-856AX) vertical gradient <br /> magnetometer was used in conjunction with a White's Instrument Metal Detector to clear the drill sites on <br /> the property that Underground Service Alert(USA)did not specifically clear on August 18,2003 All of the <br /> drill sites were outlined in white paint for USA to map and clear Followup mapping of USA markings <br /> indicated that the 521 North Cherokee Lane site did not have USA clearance identification markings and <br /> the onsite geophysical clearance was conducted <br /> On August 29 and 30,2003 a combination ground conductivity and vertical gradient magnetic survey were <br /> conducted on the property to determine if any remaining USTs and/or associated pipeline were present in <br /> the subsurface Data was collected on profiles oriented north-south at 10 foot spaced lines Individual <br /> stations were acquired on each line at 2 5 foot intervals A total of approximately 750 individual stations <br /> were acquired A summary interpretation map of the geophysical data is included as Figure 6 <br /> The geophysical data indicated the following (1)ajomt electromagnetic and magnetic anomaly is present <br /> in the area at the site where the former USTs were located It is believed that the concrete covering the <br /> former USTs contained steel rebar for strength reinforcement and that the anomalies are related to the <br /> presence of the rebar No UST is believed to be present in the former pit (2)A linear magnetic anomaly <br /> is present north of the canopy area that may be a subsurface electrical line that connects former electrical <br /> lines to their reespective.f#ci 1 ities on the east portion of the property (3)No other significant anomalies were <br /> tied that*would-suggest the presence of any other buried USTs or related product lines <br /> All work was conducted under the oversight of a California Registered Geophysicist <br /> 3.3.2 Drilling and Soil Sampling <br /> Permits to drill and complete the soil borings and monitoring wells were obtained from both PHSEHD and <br /> the City of Lodi Public Works Department (Appendix 1) The soil borings were advanced by a licensed C- <br /> 57 water well driller using a truck-mounted Mobile Drill model B-53 owned and operated by Earthtee <br /> Limited,Roseville, California <br /> Mmn1D TuvnronmentorkPunwTex"c Re s1SAR1203� Page 13 <br /> P� g <br />