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sus ,} " I�S ' '�' n n �F�,. ,' - Y i `•t .• ., i ,fi ' ,' ', s.. , L... <br /> u November 2002 ! <br /> AGE`NQProject N6..98'-0504' , ' <br /> : .Page 4 of 5 <br /> 3.3: ANALYTICAL RESULTS OF-GROUNDWATER SAMPLES :g V° <br /> TPH-g was detected in samples'from boring B3;B4'and B5 at concentrations of 240 µg/l, 300•µg/1 ; <br /> and 180 µg/1, respectively; BTEX compounds were riot detected: <br /> MTBE was detected,by EPA inethod''8260 in ground water samples B3,B4 and BS at concentrations <br /> of 80 1 200 1 and 14 1 respectively. In add_ ition,-1,2-DCA was detected in samples B3;B4 ' <br /> p� , µlb µ� , p <br /> and B5 at concentrations of 4.0 µg11,.4.0 µg1.1 and 13 µg11, respectively,and-cis',1,2-dichloroethene <br /> was detected in sample B5 at a concentration of 1.7 µg/l,'The distribution of dissolved MTBE is - <br /> depicted in.Figure 3. <br /> No other target'analytes"were detected in the samples analyzed.Analytical results from ground water <br /> ,,samples are summarized in Table 1. The laboratory report (CTEL'Lab ID 0208007); quality <br /> assurance and quality control (QA/QC) and chain-of-custody are included in Appendix B. <br /> s 4.0. SUMMARY ANWCONCLUSIONS <br /> ',Based upon soil and ground water data collected during advancement of soil borings, AGE . <br /> concludes: <br /> ' Gray and tan brown,moist to wet silt was identified at depths between 10 and 40 feet bsg in <br /> the soil borings. Ground water was encountered at approximately 40 feet bsg. �a; <br /> • MTBE was detected in'three soil samples at concentrations as great as 0.016 µg/kg, at a <br /> depth of 30 feet bsg in sample B3. <br /> MTBE and- 1,2-DCA were detected.in the grab ground .water sample from borings at <br /> maximum concentrations of.200 µg/1 and 13µg11, 'respectively. MTBE was detected at a <br /> significant concentrations above the California maximum contaminant levels.The lateral and �w <br /> vertical extent of the dissolved MTBE plume is not defined below 14 µg/1: ,} <br /> F The fuel additive 1,2-DCA was detected at concentrations above the California maximum ; <br /> contaminant level of 0.5 µg/1: 'E L__- <br /> 5.0. <br /> 5.0. RECOMMENDATIONS <br /> Based on the resultsof this investigation, AGE recommends: <br /> • Performance of additional assessment to delineate the vertical extent of MTBE-impacted <br /> ground water, at boring B4.• <br /> Advanced GeoEnvironmental;Inc. ' <br /> 'tile° ' 1� . <br /> u s P <br />