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.,r BAL%'t CHANG ASSOCIATES <br /> APPENDIX B <br /> PROCEDURES OF TEST BORING DRILLING, WELL INSTALLATION, <br /> SOIL AND GROUNDWATER SAMPLING AND SAMPLE HANDLING <br /> Techniques employed for soil and groundwater sampling are essential*ihe same asrdescribed <br /> in the LUFT manual published by the California State Water Resources Control Board.. <br /> Soil Sampling Technique <br /> Test borings are continuously cored with either a CME-45 or a CME-55 truck-mounted drill rig <br /> equipped with 3.75-inch I.D. continuous-flight hollow-stem augers. All test borings are logged <br /> by our field engineer, who also obtains representative soil samples for laboratory testing. Soil <br /> samples are taken at 5 foot intervals or less as instructed by the field engineer when field <br /> conditions warrant it. <br /> Soil samples are obtained by driving either a 2.0-inch Modified California Sampler or a 2.5-inch <br /> Modified Porter Sampler containing thin brass liners into the bottom of test borings. The <br /> procedures used in obtaining these samples are identical with the Standard Split Spoon Sampler <br /> (ASTM D-1786-84). When the sampler is withdrawn from the borings, the brass liners <br /> containing the samples are removed, field examined, labeled, and sealed for later laboratory <br /> testing. <br /> After field examination, soil samples for hydrocarbon concentration testing are sealed with <br /> aluminum foil, capped with plastic end-caps, and wrapped in duct-tape. To further preserve the <br /> samples, the samples are then placed in a refrigerated ice-chest for transportation and storage. <br /> All soil samples are also tested in the field with a Gastech combustible gas detector for gas and <br /> vapor. Based on the field analysis, the on-site soils are preliminarily evaluated in the field as <br /> to the extent and amount of contamination. <br /> Groundwater Monitoring Well Installation <br /> Groundwater monitoring wells are installed into the soil borings after logging and soil sampling <br /> are completed. The borings are drilled to at least 15 feet into the saturated layer or below the <br /> elevation of encountered groundwater (depth may vary pursuant to local regulations). If a clay <br /> 1 of 3 <br />