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Cjeorogica(Techmcs Inc Page 5 SOLI&Groundwater Investigation Report ' Ted Peters-AST . Project No 701 2 April 20,2001 3.1 Analytical Results 3.11 Soil Sample Analysis The soil samples taken from wells MW-7 and MW-8 did not contain contaminant concentrations above the laboratory reporting hinits The geology as it relates to the analytical data is discussed in the conclusion section below Table I in Appendix A contains a full summary of the analytical data and the laboratory data sheets are included in Appendix C Figure 5 illustrates the soil analytical data from the boring and Geoprobe locations compiled by GTI to date 3.1.2 Groundwater Sample Analysis After the development of the new monitoring wells, a groundwater monitoring event was conducted on March 29, 2001, and samples were submitted for analysis The results of the groundwater analysis are included as Table 2 in Appendix A The analytical data reports ' are included in Appendix C In summary . • Moderate levels of gasoline range petroleum hydrocarbons were detected in well MW- ' 7 • Well MW-8 did not contain contaminant concentrations above the laboratory reporting limits • Diesel range petroleum hydrocarbons and MTBE were not detected in the groundwater samples ' Figure 6 illustrates groundwater analytical data from the August 17, 2000, Geoprobe locations, and the February 16 & March 29, 2001 monitoring events 3.2 Site Hydrology On April 4, 2001 the "top of casing" for each monitoring well was surveyed into the City of Manteca Benchmark, No 45 by Spencer Land Surveying A site-specific groundwater gradient and bearing was calculated from the depth to water measurements taken during the groundwater February 16, 2001 monitoring event The ' gradient was 0 03 ft/ft flowing N37°E The average groundwater elevation of this site was 13 83 feet above mean sea level This data was presented in GTI's Quarterly Monitoring Report dated March 14, 2001 (submitted to the RWQCB and San Joaquin County) ' A site-specific groundwater gradient and bearing was calculated from the depth to water measurements taken during the groundwater March 29, 2001 monitoring event The ' gradient was 0 008 ft/ft flowing N43°W The average groundwater elevation at the site was 14 11 feet above mean sea level i 1 1