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GeologicafTechmcs Inc Page 4 <br /> Groundwater Monitoring Report <br /> Project No 724 2 <br /> Mai ch 13,2001 <br /> 1 sample All samples were checked for headspace bubbles, labeled, inserted into foam <br /> holders and placed in an ice chest cooled to 40C for transport to the laboratory <br />' The sampling technician, while collecting all samples, wore disposable gloves <br /> 1 A chain of custody document, listing all samples collected and their intended analyses, <br /> accompanied the samples from field to the laboratory, thereby providing a means to track <br /> their movement and ensure their integrity <br /> 13 Laboratory Analyses <br /> ses <br /> The groundwater samples collected on January 4, 2001, were delivered to Sherwood Labs <br /> of Hilmar, California (certification #1400) for analysis of <br /> 1 • Benzene, Toluene, Ethyl Benzene, and Xylene (BTEX)by EPA method 602 <br /> • Total Petroleum Hydrocarbons as Gasoline (TPH-G) by EPA method 5030/8015(M) <br /> Sherwood also sent the samples to Entech Analytical Labs, Inc for the analysis of <br /> • MTBE, DIPS, ETBE, TAME, TBA, 1,2- DCA, EDB by EPA Method 8260 <br /> The detection limits for the above analyses are Iisted 1n Table 4 of Appendix A, while the <br /> lab analytical results are pi esented in Appendix B <br /> 1 <br /> 2.0 FINDINGS AND DISCUSSION <br />' The results of the groundwater sample analysis show the following <br /> • Wells MW-1, MW-5, MW-6, MW-7 and MW-104 did not contain contaminant <br /> concentrations above the laboratory reporting limits <br /> • Wells MW-2 and MW-4 have low to moderate benzene contamination and trace to low <br /> concentrations of the other BTEX analytes <br />' • Wells MW-2, MW-3 and MW-4 contain low concentrations of TPH-G <br /> O Intermediate wells MW-106 and MW-107 contained low BTEX c,onc,entrations and low <br />' to moderate TPH-G <br /> • Deep well MW-104 did not contain contaminant concentrations above the laboratory <br /> reporting limits <br /> • Gasoline oxygenate MTBE was detected in well MW-2 and MW-107 at 5 4 and 42 ug/l, <br /> respectively <br /> The shallow groundwater plume is evident in well MW-4 and defined laterally to the east <br /> (down gradient) by MW-5 and MW-6 The presence of contamination in wells MW-106 <br /> and MW-107 suggests that a submerged plume is being sourced by residual soil <br />