ARCHIVED REPORTS XR0000928 - Laserfiche WebLink

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sampler, vertically to depths of 60 feet b`sg. Grab,ground.water samples.were collected"from each•probe boring using a Geoprobe,hydropunch. sampling,assembly..The probe rods were advanced to approximately 60 feet bsg. },.. was detected in the water samples collected from B8 and B9 at concentrations of 71 micrograms per. liter (µg/1) and 88 µg/1, respectively.,TPH-d was detected' in,the water sample ' collected from.B9-at a'concentration of 140 µg11. Ethylbenzene and total xylenes were detectcd•in" the sample from,B8 at concentrations of 1.2 µg/l and 1.3 µg11, respectively.-Toluene, ethylbenzene '. and total:xylenes were detected in the water sample collected from boring B9 at concentrations•of p. g 0.62µg/l,0.,72 p g/l and 4.3 µg11;respectively.No other analytes were detected at or above laboratory, reporting limits in the grab ground water samples"analyzed: ' ADDITIONAL SUBSURFACE INVESTIGATIONS In'October2002,four 8:25.-inch soil borin s were advanced at the site to be coni leted at monitoring ' '...wells MW-7•through'MW-1,0. Soil samples were'collected from monitoring well pilot borings at five-foot intervals, beginning at 5 feet bsg. ' Borings'MW7 through-MW 10 were completed'-as groundwater monitoring wells to further assess -. the downgradient-lateral and vertical ekten't of impacted soil and ground water.'A total of eight soil samples were collected and analyzed for TPH-g, BTEX,.EDB, 1,2-DCA and the suite of five fuel additives; including MTBE.No analytes were.detected at or above laboratory reporting limits in the soil sample analysis. In March 2004, two 8.25-inch soil borings were advanced at the site,to be completed at monitoring wells'MW-11 'and MW-12. Soil samples were collected from monitoring well pilot borings at"'" ' :'• five-foot:intei'vA "beginning at 15 feet bsg: Borings MW1.I"and MW12 were completed as-ground water monitoring,wells to further assess.the ' downgradienflateral extent of impacted groundwater. A total of four soil samples were collected and analyzed•fbr TPH-g and BEX.,No analytes were detected at or abovelal oratory reporting limits iii,the soil sample analysis: SITE STRATIGRAPHY rA mottled,pale brown and red-brown,stiff,clayey silt/siityclay was encountered from surface grade to`depths of appr6kimateiy5•feet bsg in each'boring.A pale'to dark,gray-green,silty,medium deme, _ poorly sorted fine and was generally encountered from 5 feet"to 10 feet bsg. A'pale brown to pale , +, gray, stiff, silty clay was encountered fr6m':10 feet to .20 feet bsg. A.pale brown;meditim dense; poorly sorted,'silty fine sand was generally encountered at depths between 20 feet and 25 feet bsg: I A dark brown, very stiff,'silty clay was encountered at depths greater than 25 feet bsg. - AAanced GeoEnvironmental,Inc.