ARCHIVED REPORTS_XR0010540 - Laserfiche WebLink

Home Browse Search

. Appendix A - Historical Background AGE-NC Project No 02-0964 Page 3 of 7 • Ground water elevation at the site is approximately 30 feet below well grade Ground water at the site is inferred to flow north-northeast • TPH-g,TPH-d and BTEX compounds have not been detected in ground water samples from wells MW-2 and MW-3 • During the third quarter 2004 sampling event, TPH-g was detected in well MW-1 at a concentration 27,000µg/1 BTEX compounds were detected in well MW-1 at concentrations of 160 µg/1 benzene, 24 µg11 ethylbenzene, 2,676 µg/1 toluene and 1,300 µg/1 xylenes • MTBE was detected in the monitoring well sample from well MW-2 at a maximum concentration of 9 3 µg/1 On 09 to 11 April 2003, five soil borings (CPT-1 to CPT5)were advanced on- and off-site utilizing CPT technology, at each boring location, lithologic data was collected from the initial CPT boring, an immediately adjacent twin boring was then advanced at each CPT location to collect grab ground water samples from selected depths The objective of the investigation was to model the geologic and hydrogeologic frameworks and to assess potential dissolved petroleum-migration pathways beneath the site Soil borings for sounding were as follows • CPTI was established in the vicinity of monitoring well MW-1 and soil borings A and I to a depth of 150 feet below surface grade (bsg), • CPT2 was established in the vicinity of soil borings B and 7 to a depth of 160 feet bsg, • CPT-3 was established west of boring C to a depth of 160 feet bsg, • CPT-4 was established south of monitoring well MW-1 and soil borings E and G to a depth of 150 feet bsg, and • CPT5 was advanced at the northeast corner of the intersection of California Street and Miner Avenue to total depths of 160 bsg Ground water and soil samples were collected from CPT boring locations at the following intervals • CPT-I was sampled between 96 and 100 feet bsg,between 120 and 124 feet bsg and between 146 feet and 150 feet bsg, • CPT-2 was sampled between 93 and 97 feet bsg,between 120 and 124 feet and between 146 and 150 feet bsg and between 181 and 185 feet bsg, • CPT-3 was sampled between 56 and 60 feet bsg, between 104 and 107 feet bsg, between 120 and 124 feet bsg and between 143 and 147 feet bsg, • CPT-4 was sampled between 101 and 105 feet bsg, between 120 and 124 feet bsg and between 141 and 145 feet bsg and Advanced GeoEnvironmental