ARCHIVED REPORTS_XR0011307 - Laserfiche WebLink

Home Browse Search

Crtologko(7-ecludaInc Page 5 Groundwater Monitoring Report Project No 989 2 November 18,2004 water moving in the tubing Water samples were transferred from the tubing into 40-nil VOA vials, preserved with hydrochloric acid, while minimizing sample aeration during ' transfer of the sample All samples were checked for headspace bubbles, labeled, inserted into foam holders and placed into a cooled ice chest for transport to the laboratory ' The sampling technician wore disposable gloves while collecting all samples A chain of custody document, listing all samples collected and their intended analyses, ' accompanied the samples from the field to the laboratory, thereby providing a means to track the movement of the samples and ensure their integrity ' 2.2 Laboratory Analyses ' The groundwater samples collected on October 13, 2004, were delivered to Sherwood Labs Corporation (FLAP# 1400), of Hilmar, California, for the following analyses • Benzene,toluene, ethyl benzene and total xylenes (BTEX)by EPA method 8020/8015 ' • Gasoline range petroleum hydrocarbons(TPH-G) by EPA method 8020/8015 • MtBE by EPA method 8260 The detection limits for these compounds are listed in the laboratory data sheets included in Appendix C and summarized in Table 3 of Appendix A A Chain of Custody was completed for all samples collected and tracked to ensure sample integrity ' On November 12, 2004, the laboratory data were submitted electronically to GeoTracker as required under AB2886. The confirmation number for the electronic submittal is ' 4740447759 2.3 Groundwater Analytical Results ' • Low concentrations of TPH-G and trace concentrations of some BTEX constituents were ' detected in MW-1 TPH-G and BTEX constituents were not present in any other monitoring wells above laboratory reporting limits • A plot of TPH-G versus groundwater elevation for MW-1 shows that generally the ' concentrations of TPH-gasoline fluctuate with groundwater elevation and that the overall concentrations have decreased two orders of magnitude over time • Concentrations of MtBE, below MCL's were detected in the following monitoring wells MW-1,MW4, MW-7 and MW-9 • Low concentrations of MtBE were present in MW-5, MW-6 and MW-8 The levels are consistent with previous monitoring events Laboratory Data Sheets are included in Appendix C Groundwater analytical data is summarized in Table 3 of Appendix A Chart 1 is a plot of TPH-G versus groundwater I