ARCHIVED REPORTS_XR0010387 - Laserfiche WebLink

Home Browse Search

3,2 Analytical Results A summary of the analytical data for the March 22,2005 groundwater sampling event is presented in Table 3-2 Histoncal groundwater analytical results are presented in Table A-1 in Appendix A The analytical ' reports and chain of custody forms are presented in Appendix C Petroleum hydrocarbons were detected in samples collected from monitoring wells MW-2 and MW-2A ' Benzene,ethylbenzene,and total xylene were detected in monitoring wells MW-2 and MW-2A,toluene was detected in monitoring well MW-2A ' TPH-g and BTEX compounds were not detected in the upgradient monitoring well MW-9, nor in the equipment blank water sample (EB-1) ' Table 3-2 Organic Analytical Results San Joaquin County Human Services Agency ' March 2005 Results presented in micrograms per liter(MWL) ' Well Groundwater Benzene Toluene Ethylbenzene Xylene TPH-g Elevation (total) feet MSL MW-2 NM 14,000 ND(0 50) 120 140 21,000 MW-2A -1898 64 47 80 26 2,100 MW-9 -1901 ND(0 50) ND(0 50) ND(0 50) ND(0 50) ND(50) EB-1 NA ND(0 50) ND(0 50) ND(0 50)__r;ND(0 50) ND (50) ' NA=not applicable ND()=analyte not detected,detection hrrut indicated to parentheses NM--not measured ' 4.0 CONCLUSIONS ' Since the previous sampling event in December 2004,concentrations of benzene,ethylbenzene,total xylene, and TPH-g have risen in monitoring well MW-2,toluene levels retrain non-detectable Concentrations of benzene,toluene,total xylene,and TPH-g found in monitoring well MW-2A have increased when compared ' to the last data set from December 2004(toluene was not detected in this data set),ethylbenzene levels have decreased slightly These concentrations are consistent with historic concentrations found in previous sampling events and represent minor fluctuations in contaminant levels No contaminants of concern were ' detected in upgradient monitoring well MW-9 4