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20 November 2003 •- -- 2° _ - <br /> AGE-NC Project No:.96=0263 - <br /> t ' ` 3 <br /> Page 3of11 r <br /> Based on fifteen groundwater monitoring-Events recorded-at the site between December.-1999 and =�- <br /> July 2003, depth to ground water measurements=have fluctuated between 6.6 and 8:9 feet,bsg, The <br /> hydraulic gradient'has been relatively flat at-the site, ranging between 0.003 feet/feet and 0.006 <br /> feet/feet.-Ground water flow direction has been inferred to be towards the north-northwest and <br /> _ northwest. Depth to ground water and ground water elevation data are summarized in Table 2. '­' - <br /> 3.0. SUMMARY OF.PRELIMINARY INVESTIGATION.AND EVALUATION I <br /> Site assessment activities summarized below were originally reported In various reports prepared i <br /> by AGE between March 1999 and September 2003,App eridix-A contains a list of reports referenced - <br /> in preparing this summary. The following is-a-summary sof signifieant assessment, activities <br /> conducted to date at the-Tracy Marine Sales site. <br /> _ 24 June 1998 --Nine soil probe boring-(B-1'through B-9) were advanced at.the.site. Soil <br /> samples were collected and analyzed from borings B-1 through B-7 and grab groundwater <br /> samples were collected and analyzed•fr`om'borings B-1 B-3, B-5; B-6, B-7, B-8;and B-9 <br />- ' TPH-g was,detected in nine of fifteen.soil samples analyzed from seven of the soil probe <br /> borings at coheeritrations_as high as..670-mg/kg (sample B4-5'): BTE&X compounds were I <br /> 'detected in eleven- of-the fifteen• soil,samp' les analyzed. The'.-greatest concentrations'of. <br /> BTE&X compounds detected.were generally in soil-samples collected at depths of five and <br /> ten•.feet bsg. MTBEwas detected-in- -twelve of...the fifteen. soil samples analyzed--at = <br /> concentrations as high as 43 mg/kg(B540'). TPH-g was detected in four of the.seven grab. <br /> ground water samples collected-froze the site at concentrations ranging from 3,200 to 27;000.' w <br /> micrograms per"liter(µg/i)..BTE&X compounds were detected in'four of the water samples' <br /> at concentrations as high as 2,100 4g/lbenzene,3,900 µgl�toluene; 1,100µgh'ethylbenzene <br /> and 5,400 µg/l-total xylenes. In additid4;'1VITBE was detected in five of the'seven samples _ <br /> ~ _ analyzed at concentrations ranging from'65 µg/l to 11:,000 µg/l,Analytical resultso-f soil and <br /> grafi ground water samples are summarized in Tables 3-'and 4 { <br /> • November 1999-Eight soil borings were advanced at the site and completedas ground water . <br /> - monitoring wells. TPH-g was detected in soil samples collected.-from pilot borings MW=2; <br /> T <br /> MW-4, MW-5 and.MW-6 at concentrations as hiigli as.150 (mg/kg): BTE&X compounds . <br /> were detected at concentrations aAigb as 0.82 mg/kg of benzene; 1.7 mg/kg <br /> :of toluene,4.8 <br /> - <br /> _ mg/kg of ethylbenzene and-14 mg/kg oflo-tal,xylerles. MTBE was detected in soilsamples _ <br /> collected from monitoring well pilot borings MW2, MW4, .MW5, MW6 an MW8 at <br /> T concentrations.as high as 0.003 mg/kg(MW2=5).No.other oxygenates were detected in:the <br /> soil sample analysis. Petroleum hydrocairbons were not detected-iri samples collected from <br /> soil borings MW f and MW3.-Analytical'.results of soil samples-are 5umriiarized on Table'-3. <br /> • March 2001 -Four Cone Penetrometer_Testin CPT soil borin s CPT-1 through CPT-4 <br /> were advanced at the site.TP_H-g was not detected in the soi l and grab ground water.samples <br /> 4dvanced GeoEnvironmental,Inca _ <br />