ARCHIVED REPORTS XR0009209 - Laserfiche WebLink

Home Browse Search

' Geolo icafTechnics Inc 9 Page 3 Groundwater Monitoring Report ' Project No 723 2 . December 6, 1999 ' Before a sample was collected, the well's water level was allowed to recharge to at least 80% of the initial level All water removed from the monitoring well and not used as a sample, ' was placed in a 55 gallon DOT (Department of Transportation 17-H) approved container that is properly labeled and temporally stored on-site ' The dedicated Waterra pump was used to collect each sample Extreme care was exercised while transferring the sample into 40-m1 VOA vials preserved with hydrochloric acid All samples were checked for headspace bubbles, labeled, inserted into foam holders and placed in an ice chest cooled to 4°C for transport to the laboratory IThe sampling technician while collecting all samples wore disposable gloves A chain of custody document, listing all samples collected and their intended analyses, accompanied the samples from field to the laboratory, thereby providing a means to track their movement and ensure their integrity I1.3 Laboratory Analyses The groundwater samples collected on September 13, 1999 were delivered to Sherwood Labs of Hilmar, California(certification#1400) for analysis of • Benzene, Toluene, Ethyl Benzene, and Xylene (BTEX) by method EPA method 602 • Total Petroleum Hydrocarbons as Gasoline (TPH-G) by EPA method 5030/8015(M) • Methyl Tertiary Butyl Ether(MTBE) by EPA method 602 • Fuel Oxygenates (MTBE, DIPE, ETBE, TAME & TBA)by EPA method 8260B IThe detection limits for the above analyses y s are listed in Table 2 of Appendix A while the lab analytical results are presented in Appendix B 2.0 FINDINGS AND DISCUSSION The results of the groundwater sample analysis show the following • BTEX and TPH-G concentrations continued to increase in MW-1, MW-2, MW-5 and MW-6 and decreased in MW-3 & MW-4 • MW-101 showed moderate levels of BTEX and TPH-G This well was installed through I upper, heavily contaminated soil and groundwater GTI has observed that these wells I will typically test positive for contaminants due to contaminated soil and groundwater being dragged down the borehole during drilling GTI recommends several quarters of monitoring to see if the levels decrease before further deep investigation is continued • All of the wells showed the presence of MTBE from the EPA 602 analysis However the EPA 8260B analysis did not show that MTBE was present