Laserfiche WebLink
and groundwater observations were consistent with previous reports. The report <br /> indicates that the vertical delineation in groundwater was not achieved. <br /> April 26, 2004 Additional Groundwater Delineation Report (Clayton): Documents the <br /> drilling of 2 additional soil borings (B-66 and B-67; deepest at 238 ft bgs at B-67) and the <br /> results for groundwater samples collected in the area of Trenches 3 and 4. The soil <br /> borings indicate the presence of unconsolidated sand and clay layers to a depth of <br /> approximately 160 ft bgs and a heaving sand unit below this depth to approximately <br /> 177 ft bgs which appears to be continuous to the maximum soil boring depth at 238 ft <br /> bgs. TPH as crude oil(TPHc)was detected in the deep sample collected at 238 ft bgs. <br /> April 22, 2005 Status Report (Clayton): Documents the forensic analysis performed by <br /> Shell. Concludes that the deeper site sample (Boring B-66) with TPH concentrations at <br /> 171.5 feet is most likely the result of a naturally occurring erosional deposit or an oil <br /> seep,not related to the pipeline. <br /> September 28, 2005 Status Report (Clayton): Provides additional discussion on the <br /> forensic analysis performed by Shell and concludes the hydrocarbons detected at <br /> 171.5 feet are not related to the pipeline and appear to be naturally occurring. Also <br /> suggests that that shallow hydrocarbons attenuate at depths of approximately 40 feet <br /> and that the hydrocarbons detected below approximately 50 feet are different in nature <br /> than the shallower hydrocarbons. <br /> August 6,2007 Site Investigation Report(SAIC): Documents the soil and groundwater <br /> assessment results for further evaluating the lateral extent of hydrocarbon impact in the <br /> interval between 40 and 150 ft bgs (borings B-75 and B-76). Additionally, presents the <br /> soil vapor sampling results for borings B-70,B-71,B-72 and B-74. <br /> January 8, 2009 Site Investigation Report (CRA): Documents the horizontal extent of <br /> groundwater impacts northeast of B-75 and identifies additional water supply wells; <br /> describes advancing of borings B-77 and B-78 and provides results on B-77 and B-78. <br /> September 1, 2009 Site Conceptual Model (CRA): Provides a site conceptual model <br /> (SCM). The SCM describes the relationship between the source area, transport <br /> pathways, and potential receptors. CRA developed the SCM based on review of <br /> available geological and analytical data. Supporting documents for the SCM include <br /> historical soil and groundwater analytical data, available boring and well logs, geologic <br /> cross sections,a sensitive receptor survey,and a list of key environmental reports. <br /> 060223(33) A-3 CONESTOGA-ROVERS&ASSOCIATES <br />