WORK PLANS FILE 1 - Laserfiche WebLink

Home Browse Search

Site Background Information: West Clay Properties Page 6 of 10 • CPT-13 and associated ground water sampling boring were advanced near the southern sidewalk of Clay Street, approximately 45 feet south of boring CPT-11. CPT-13 was advanced to approximately 53 feet bsg and was terminated due to refusal. CPT-13 was sampled between 53 and 57 feet bsg. • Ground water sampling boring CPT-14 was advanced approximately 70 feet east of CPT-13 to determine the lateral and CPT-14 was advanced to approximately 58 feet bsg and terminated due to refusal. Boring CPT-14 was sampled between 74 and 78 feet bsg. The analytical results of the grab ground water sample collected from each sampling interval in borings off-site , south and east of the former UST No. 3 location had no detectable concentrations of the chemicals of concern (CPT-10 through CPT-14). ADDITIONAL ON-SITE MONITORING WELL INSTALLATIONS -VERTICAL Between 10 and 19 October 2005, ten additional monitoring wells were installed at the site. Well EW-1 was installed in the norther UST area as a ground water monitoring well using two-inch diameter PVC casing with 0.020-inch slotted screen, from approximately 10 feet to 30 feet bsg. Nine wells were installed surrounding the southern UST area: Wells MW-16,MW-18 and MW-21 were completed as Hydrogeologic Unit 3 (HU3) two-inch, ground water monitoring wells from approximately 75 feet to 85 feet bsg; Wells MW-17,MW-19 and MW-20 were completed as upper HU4 two-inch, ground water monitoring wells from approximately 95 feet to 105 feet bsg; and Wells MW-23, MW-22 and MW-24 were completed as lower HU4 two-inch, ground water monitoring wells from approximately 135 feet to 140 feet bsg. GENERAL STRATIGRAPHY Dominantly fine-grained soil consisting of silt, clayey silt, silty clay and clay were encountered at depths from the near surface to approximately 185 feet bsg. Significant sand units with variable silt to gravel were encountered between 20 feet and 40 feet bsg, 62 feet to 90 feet bsg and 165 feet to 191 feet bsg.The shallow sand unit(20 feet to 40 feet bsg)appears to have limited lateral continuity. The sand unit encountered at 165 feet bsg appears to have lateral continuity and a documented thickness of greater than 40 feet. Lessor, thin, laterally discontinuous sand units were encountered at approximately 50 and 100 feet bsg at the southern UST No. 3 area. CPT computer-generated boring logs are included in Appendix B. Based on the findings from the previous CPT soil borings and existing monitoring well and soil borings,cross sections A-A'was constructed to depict general lithology beneath the UST No. 3 area and directly south of the site. .Advanced GeoEnviron mental.Inc.