ARCHIVED REPORTS XR0007599 - Laserfiche WebLink

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1 ' Ground water• samples collected and analyzed from the water table or the hydrologic unit one are reported as follows ' + TPH-g was reported in a sample from the upper most water table TPH-g was detected in sample CPT3-55 at a concentration of 100 micrograms per liter (µg/1) TPH-g was not ' detected in the other shallow grab water sample VOCs (BTEX and fuel additives)were not detected in the shallow grab water samples Monitoring well data indicates significant concentrations of TPH-g and VOCs (BTEX and fuel additives), near the upper 60 feet of the section at CPTI and to a less degree at upper 60 feet of the section at CPT2 • TPH-g was reported in a sample from the a depth of 75 to 90 feet bsg TPH-g was detected ' in sample CPTI-88, CPT2-80, CPT3-75 and CPT4-82 at concentrations of 1,800 µg/l, 250 µg/l, 170 ug/l and 470 gg/l, respectively BTEX compounds were detected at a maximum concentrations of 34µg/1 ofbenzcne in sample CPT 1-88 Xylene was detected in sample from ' HU2 at a maximum of 6 6 Ag1l in sample CPTI--88 DIPE was detected in the same sample at 11 µg/I ' • TPH-g was reported in a sample from the a depth of 100 to 125 feet bsg TPH-g was detected in sample CPT1-115, CPT2-115, CPT3-122 and CPT4-125 at concentrations of 290 µg/l, 230 µg11, 1,400 µg/1 and 140 gg/l, respectively TPH-g was also detected in sample ' CPT3-100 at 310 µg/l BTEX compounds were detected at a maximum concentrations of 370 gg/l of benzene m sample CPT I-122 Xylene was detected in sample from HU3 at a maximum of 13 6 µg/1 in sample CPT3-122 DIPE was detected in the sample CPT I-115 at • 6 2 gg/l o The only hydrocarbon detected in soil sample was at 0 034 mlIligrams per kilogram of benzene in sample CPT4-60 o Overall, TPH-g and BTEX compounds were detected in the water sample collected from the lower two hydrologic units ( HU2 and HU3) Xylenes were also detected in the lower two HUs The concentrations of benzene appear to increase with depth both on-site at CPT I and north of the site at CPT3 While no benzene was detected in the CPT2 samples, at former ' UST area, collected at these sample deep intervals of 80 to 125 feet bsg o The vertical extent of petroleum hydrocarbon-impacted ground water has not been defined I HYDROGEOLOGICAL MODEL Based on the CPT results, AGE has developed a preliminary subsurface model of the site sediment stratigraphy comprised of three informal zones, a vadose (unsaturated) zone and two hydrological units Hydrological units may be defined as significant vertical intervals of soil having significant lateral extent and having similarhydrologic characteristics(i e hydraulic conductivity,transmissivity, etc) over its vertical and horizontal extent A `flow unit' may be defined as a hydrologic unit and is Icharacterized by significantly greater hydraulic conductivity values than overlying and underlying • units A flow unit is capable of serving as a preferred migration route, and could potentially allow migration of large contaminant masses over great distances Advanced GcaEnvlronmentA Inc