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lFerpxTdopi NC <br /> 3.0 GROUNDWATER SAMPLING <br /> The following sections describe the groundwater sample collection, groundwater <br /> Ilaboratory analytical results and waste storage and disposal Samples were collected according <br /> to the Sampling and Analysis Plan submitted in Versar's site investigation workplan, dated <br /> August 2, 1995, and workplan addendum, dated May 10, 1996 <br /> 3.1 Groundwater Sample Collection <br /> / p <br /> ' On September 5, 1996, groundwater samples were collected from the three groundwater <br /> monitoring wells at the Site Prior to purging and sampling, depths to groundwater in monitoring <br /> wells MW 1, MW2, and MW3 were recorded at 43 96, 44 05, and 43 77 feet bgs, respectively <br /> Each monitoring well was purged of approximately three casing volumes of water, the water <br /> level was allowed to recover to at least 80 percent of the pre-purge level, and then the wells were <br /> sampled Data collected prior to and during purging and sampling were recorded on monitoring <br /> well purge tables included as Appendix A <br /> 1 Samples were collected, placed in containers, preserved, and analyzed within the time <br /> constraints consistent with applicable regulatory agency requirements Samples were tracked <br /> using Versar's chain-of-custody forms The sampling team maintained custody of the samples <br /> from the time of collection until submittal to the laboratory <br /> 3.2 Groundwater Sample Analytical Results <br /> Three groundwater samples were collected and submitted for laboratory analysis Each <br /> sample was analyzed by Excelchern Environmental Labs, California certification 92119 MW2 <br /> was analyzed for TPH-JP4, TPH-G, BTEX, and MTBE Based on the previous quarter's <br /> analytical results and with approval from Mike Infurna of PHS/EHD, MW 1 and MW3 were <br /> ' analyzed for TPH-JP4, BTEX and MTBE only Analytical results for the groundwater samples <br /> identified no concentrations of TPH-JP4, THP-G, BTEX, and MTBE at or above laboratory <br /> detection limits The detection limits were as follows, TPH-JP4 and TPH-G at 50 pg/L, BTEX <br /> at 0 5 pg/L, and MTBE at 5 0 pg/L This reporting limit for MTBE is higher than the reporting <br /> limit of the previous quarter The reporting limit for all MTBE analyses was increased by the <br /> laboratory for improved reporting confidence levels Levels of MTBE may be present at the <br /> reporting limits (0 5 pg/L) of the previous quarter <br /> 6 <br />