ARCHIVED REPORTS_XR0007751 - Laserfiche WebLink

Home Browse Search

07 March 2002 S AGE-NC Project No 99-0637 Page 4 of 6 The model presented 1s interpretational and will be modified as more data is collected The six vertical zones identified are as follows (depths are approximate and can vary by several feet across the site) Vadose Zone-Extending from surface grade to 18 feet bsg,the depth to the water table The vadose zone is predominantly coarse grained material(sand) with fine grained soil occurring from surface grade to 10 feet bsg across a portion of the site The zone is characterized by low pore pressure Hydrological Unit 1 (HU1), at the top of the current saturated zone, extends from 18 feet to 31 feet bsg and is comprised of clay and silty clay and characterized by low to moderate pore pressures Hydrological Unit 2 (HU2) extends from 31 to 45 feet bsg, is predominantly coarse grained sands Iand gravelly sands, and is characterized by very low to low pore pressures Hydrological Unit 3 (HU3) extends from 45 feet to 60 feet bsg, is comprised of clay and characterized by low to high pore pressure Hydrological Unit 4 (HU4) extends from 60 feet to 80 feet bsg and consists primarily of coarse grained soil HU4 is characterized by very low pore pressures with thin,localized high pore pressure Hydrological Unit 5 (HU5) extends from 80 feet bsg to and possibly beyond 112 feet bsg near the total depth penetrated by all three CPT bonngs Silt and clay are the dominant soil type in the interval The interval is characterized by pore pressure variations from moderate to high pressures 33 LABORATORY RESULTS OF "GRAB" GROUND WATER SAMPLES A total of nine grab ground water samples were collected from CPT-1, CPT-2 and CPT-3 and submitted for laboratory analysis for the above listed constituents Ground water samples were collected from CPT-1 at the following intervals 41 feet to 45 feet bsg(HU2), 64 feet to 68 feet bsg (HU4)and 82 feet to 86 feet bsg(HUS),from CPT-2 at the following intervals 41 feet to 45 feet bsg (HU2), 64 feet to 68 feet bsg (HU4) and 79 feet to 83 feet bsg (HU5) and from CPT-3 at the following intervals 41 feet to 45 feet bsg (HU2), 64 feet to 68 feet bsg(HU4) and 81 feet to 85 feet bsg (HU5) TPH-d was only detected in the water sample collected from CPT-3 at 41 feet to 45 feet bsg(HU2) at a concentration of 54 micrograms per liter(µg11) TPH-g and BTEX compounds were not detected at or above laboratory reporting limits in any of the ground water samples • Advanced GeoEnvironmental,Inc