ARCHIVED REPORTS_XR0012704 - Laserfiche WebLink

Home Browse Search

F ILLL The results of the laboratory analysis of ground water samples are presented in Table 1. The official laboratory reports and chain of custody documents are included in Appendix G. 5.0 DISCUSSION OF RESULTS ~ A brief description of site geology and hydrogeology based on the results of the drilling activities is presented below. The results of field activities and laboratory analysis of the soil and ground water samples collected during this investigation and from previous investigations are also discussed below. 5.1ll r,P�v Boring logs generated during this and previous subsurface investigations indicate that the stratigraphy beneath h the site is complex and varies ve_tically a The area of excavation has been backfilled with sandy gravel to a depth of approximately 10 feet below grade. The predominant soil types at the site are sand/silt/clay mixtures with raccasioroximatelyal 1141feet sbelow gradethat d from ground surface to aPP generally underlies the sand/silt, silty clay was encountered Clay mixture. At approximately 19 feet below grade, in all soil borings to the total depth of the borings. Figure 4 shows the northwest-southeast hydrogeologic cross section A-A' ' while the west--east hydrogeologic cross section B-B' is shown in Figure 5. 5.2 €1, Ground water was first encountered during drilling and sampling of all borings at depths of appprximately1005tfeet 11 feet below grade, stabilizing at approximately below grade. Ground water elevations from weregusedto Wel1AW-1 through develop the Aw-8, as measured on May ground water potentiometric surface map shown in Figure 3. r flow direction ioottheees The general ground watenortheast, with calculated from these measurements, is } an average hydraulic gradient of 0.014 foot per foot across the site. 9