Laserfiche WebLink
' 28 April 2004 <br /> AGE-NC Project No 99-0570 <br />' Page 4 of 6 <br /> be' defined as a hydrogeologic unit and is characterized by significantly greater hydraulic <br /> Iconductivity values than overlying and underlying units, a flow unit is capable of serving as a <br /> preferred migration route, and could potentially allow migration of large contaminant masses over <br />' great distances <br /> The model presented is interpretational and will be modified as more data is collected The four <br /> vertical zones identified are as follows (depths are approximate and can vary by several feet across <br />' the site) <br /> Vadose Zone - Extending from surface grade to approximately 15 feet bsg, the depth to the water <br /> Itable The vadosezone is predorninantiv fi med material from surface grade to 15 feet bsg,with <br /> Ca-coarse grain sar_d-unit occurring-between-�O—feet;an --25 feet-bsg at CPT2 T e zone--}s-terized by low pore pressures Sys da e,5 0) <br />' YON <br /> Hydrogeologic Unit 1 (HU1), at the top of the curr nt saturated zone, extends from 15 feet to <br /> approximately 60 feet bsg and is comprised laterally continuous alternating layers of poorly graded <br />' sand with silt and silty sand This unit has flow unit characteristics <br /> Hydrogeologic Unit 2,(HU2) extends from 60 feet to approximately 90 feet bsg and is composed <br />' dominantly of stiff, fine-grained soil, silty clay with a thin bed of poorly graded sand at 80 feet bsg <br /> Hydrogeologic Unit 3 (HU3) extends from 90 feet bsg to total depth, HU3 is composed of <br />' interbedded stiff, fine-grained soil, silty poorly graded sand, silty clay and silty sands from 90 feet <br /> bsg to approximately 110 feet bsg This unit has flow unit characteristics S anal +,� 4..,' #0 C?'b <br />' Hydrogeologic units are depicted in cross sectional view B-B' (Figures 4) <br /> r <br />' 33 LABORATORY RESULTS OF GRAB GROUND WATER <br />' A total of eight grab ground water samples were collected from HU1,HU2 and HU3 and submitted <br /> for laboratory analysis for the constituents listed in Section 2 2 <br /> HU 1 1 <br /> I <br /> Grab ground water samples CPT1-55, CPT2-55 and CPT3-55 were collected from HU1 (Table 2) <br />' No constituents of concern were detected at or above laboratory reporting limits in any of the ground <br /> water samples collected from HUI <br />' HU2 <br /> • Grab ground water samples CPT1-80, CPT2-89 and CPT3-85 were collected from HU2 (Table 2) <br /> IAdvanced Geoinvironmental,Inc <br /> I <br />