Laserfiche WebLink
- 14 - <br />SUBSURFACE Q~PIDITI~IS <br />Subsurface conditions at our test boring locations varied across • <br />the site. A description of the subsurface conditions encountered is <br />presented below for the valley, the south hillside, the dam site, the <br />water tank and the haul road. The Logs of Exploratory Holes are shown <br />on Figs. A-1 through A-6. Test hole locations are plotted on Fig. 3. <br />Valley: T9ie natural soils in the valley bottom in the vicinity of the <br />administration, change house and shop warehouse building are <br />predominantly mixtures of silt and fine sand. These soils were <br />encountered to depths of between 7 and 13 feet. <br />The silt and sand mixtures encountered contained varying minor <br />percentages of clay and scattered angular gravels. Angular gravels <br />a~ some cobble size fragments were the dominant soil size in the <br />upper 7 feet of Test Hole S-1 at the administration building. Based <br />on the field penetration testing and the laboratory testing, the soils <br />appear to be very stiff in consistency or dense to very dense. These <br />sand and silt soils are generally dry and light brown in color. <br />The bedrock encountered beneath the overburden soils in Test <br />Holes S-1 through S-4 consisted of a silty to very silty claystone <br />bedrock. The bedroc]c was encountered to the maximum depth explored in <br />this area, 21 feet. The claystone was carbonaceous in places and gray <br />to black in color. <br />South Hillside: Few natural soils were encountered in the test <br />borings drilled on the south hillside in the vicinity of the <br />processing facilities and the storage silos. The soils encountered <br />ranged to a maximun depth of 6 feet. Generally, the materials <br />L <br />