Laserfiche WebLink
2 <br /> SOIL SAMPLING PROCEDURES <br /> The soil sampling locations are shown in Figure 2, Three <br /> locations have been selected in areas of known contamination <br /> to determine the vertical extent of contamination. The other <br /> sampling locations have been selected around the perimeter to <br /> identify the horizontal extent of contamination. Hopefully, <br /> clean soil will be found in the perimeter borings. If the <br /> perimeter borings show gross contamination, additional <br /> borings will be drilled. <br /> Boxings will be drilled using a truck-mounted drilling rig <br /> equipped with hollow-stem continuous flight augers. use of <br /> hollow stem augers will ensure sample integrity by preventing <br /> soils from caving to the bottom of the boring during <br /> drilling. To collect an undisturbed soil sample while <br /> drilling each boring, a California modified sampler with <br /> brass liners will be pushed ahead of the auger. This method <br /> of drilling and sampling reduces the potential for cross <br /> contamination of samples. <br /> Borings will be logged by a qualified ERM-west geologist or <br /> soil scientist. Soil types will be classified in accordance <br /> with the unified Soil Classification System (Figure 3) . <br /> Borings will be drilled to a maximum depth of 20 feet. <br /> Although groundwater depth in the area is expected to be ' <br /> i greater than 20 feet, if ground water is encountered at less <br /> than 20 feet, then drilling and sampling will be halted at <br /> the groundwater level, <br /> is <br /> Soil sampling will commence at the interface between the fill <br /> material and the native subsoil. Sam les will be collected <br /> continuously and checked for odors of hydrocarbons to a dep h �ozcJ <br /> of 20 feet. After the last sample from each boring is �5 <br /> collected and checked, at least two samples will be selected <br /> for analysis. Sample selection will be based on odor and r a, <br /> visual observation with the objective of defining the <br /> vertical extent of the contamination. All drilling and <br /> sampling equipment will be steam cleaned prior to drilling <br /> each boring to prevent contamination between borings. <br /> The soil cuttings from the borings will be placed in labelled --E-5 <br /> drums pending laboratory analysis. The boring holes will be <br /> filled with grout after sampling is completed, <br /> The ends of the brass tubes containing soil samples will be <br /> covered with Teflon film and plastic caps to provide an air <br /> tight seal. Each sample tube will be appropriately marked on <br /> site with the boring number, samole designation, date, time, <br /> and depth. Samples will be placed on ice in a cooler and <br /> transported to a State-of--California certified laboratory for <br /> analysis. <br /> wb <br />