SITE HISTORY_FILE 1 - Laserfiche WebLink

Home Browse Search

&Anurface 1n _ tigatlm Resotte 4.131 Va^ffic Ave., Stockton, eA. Ae91e Project No. 90-020 Page 9 i A TE IdXAAOOEOL4GIC/ REGIONAL GEOLOGY A complete review of the is included in Aegis' Pre-Tank Replacement Site Assessment Work Plan (Aegis March 6, 1990) . 2.9 WATER WELL I*:FORMATION A water well search will be conducted through the State of ca-iifornia Department of Water Resource.^, to located water wells _'_thin 1/2 mile radius of the Site. 3.0 RESULTS OF SUBSURFACE INVESTIGATION A total of fourteen soil borings were advanced at the locations shewr. on Figure B. Soil borings B-9 through B-14 were: advanced to 1.. 0 feet below grade. Soil borings B-2 through B-8 were advanced 46.0 feet below grade, soil boring B-1 was drilled to 55 feet below grade. Logs of the soil borings are included in Appendix B. A total of 28 soil samples from the borings were submittel to a state-certified-laboratory for analyses. Copies of laboratory ; reports are included in Appendix C. 3.1 SOIL CONDITIONS Fourteen soil borings were drilled, sampled and logged, ac�ording to the methods described in Appendix A (B-1 was not samples) . The soil borings ranged from 21.0 ft. to 55 ft. below grade. Sail Loring B-1 was advanced to ground water, away from suspected soil contamination. Ine soil boring logs were used to compile generalized cro= sec,-.ion A-A, ' which is presented in Figure 6. As depicted -In the -- cross section, silts varying--fromclayey. to scndy composition were the predominant soil type encountered (unified Soil Classification System symbol ML) . Generally silty clays occurred at shallow depths, followed by interlayered horizons of sa::%dy silts. Most of the deeper borings ended in clayey silts. Soil types ranged from a fine grained silty clays to medium grained silty sand, to sand. As shown on the cross section, soil type- '- beneath the site generally coarsen with depth.