ARCHIVED REPORTS_1992-1993 - Laserfiche WebLink

Home Browse Search

File No. 20-3668-01 n K L E I N F E L D E R January 7, 1993 2-inch inside-diameter sampler into the soils using a 140-pound hammer falling approximately 30 inches. The number of blows required to advance the sampler into the soils is presented on the Logs of Borings, in the appendix, Plates A-3, A-4 and A-5, at the corresponding sample locations. In addition, five backhoe test pits were excavated on November 25, 1992 to depths of 10 to 13 feet and five additional test pits on December 16, 1992 to depths of 8 to 11 feet. SOIL CONDITIONS Over the majority of the site not covered by asphalt, the surface soils consisted of fine grained silty sand. Boring B-1 indicated some debris and gravel in the upper surface layers; however, this material is likely due to waste handling operations in connection with the existing transfer station. With the exception of Boring B-2, our field explorations generally indicated that the L subsurface soils consisted of silty sand with interlayers of clayey silty sand or sandy silty clays to the maximum depths indicated. The soil density varied from very loose near the surface in the cultivation zone, to very dense at depth. Layers of partially cemented silts, known locally as "hardpan" were encountered at depths below 5 feet. The thickness of these layers varied. Boring B-2 encountered old landfill debris consisting of glass, metal, tires, and ash to depths of approximately 171/4 feet. Backhoe Test Pit 2 was excavated to the north of Boring B-2 to further evaluate the extent of the debris. Based on visual observation, it appears that the debris extends approximately 11 feet deep. In our opinion, the debris shown below 11 foot in B-2 likely was caused by debris falling off the sides of the hole during drilling operations. Test Pits 5 and 3 were also excavated to evaluate the extent of landfill debris. Both test pits indicated only minor debris, approximately 1A to 2 feet, respectively, below approximately 1 foot of cover soil. On December 16, 1992 five additional test pits were excavated in the vicinity of Boring B-2 to further evaluate the extent and depth of buried debris in that area. Results from those excavations indicate that the debris varies in depth from 7 to 9 feet and extends nearly the entire distance from T -5 t the existing paved driveway. Reference is made to Plates A-1 and entire. We caution that the reported thicknesses of debris are only indicative of the locations explored and are given for approximating the locations of old landfill cells and debris volume. Test Pit 5 encountered clean, cohesionless sand below approximately 9 feet in depth. i . According to the current land owner, the soil profile becomes more cohesionless (grading ■ towards "sugar sand") to the eastern portion of the project site and beyond. Groundwater was encountered in several of the borings drilled for this investigation. Three borings were left standing for two days to allow the normalization of groundwater levels in the bore hole. ., ..dg Borin B-4 Copyright 1993 Kleinfelder, Inc. Page 3 of 11