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or Plan Description Subsurface Investigation Page 2 Foothill Landfill LFGTE Facility Linden CA August 4, 2011 Project 3310 encountering hazardous material or soil contamination. One of these prior test borings is 1,500 feet north of currently proposed work site area. As a consequence,no hazardous material or soil contamination is anticipated. Based on prior test borings,the depth to groundwater is anticipated to be on the order of 60 feet or deeper. EXPLORATION PROGRAM The geotechnical subsurface exploration program will be carried out using a truck- mounted CME 75 drilling rig with hollow-stem augers or solid-stem augers drilling five, 5-inch to 8-inch diameter test borings within an approximately 100 foot by 200 foot area. The test borings will be drilled to depths of 10 to 30 feet below the adjacent ground surface. The materials encountered in the test borings were continuously logged in the field by a geotechnical engineer. The materials are described in accordance with the Unified Soil Classification System(ASTM D-2487). Material samples will be obtained from the test borings at various depths using a 3.0-inch outside diameter(O.D.),2.5-inch inside diameter(I.D.)Modified California split-spoon sampler and a 2.0-inch O.D., 1.5-inch I.D. Standard Penetration Test split-spoon sampler. The Modified California and California samplers were fitted with a series of 6-inch long,thin-wall brass liners. Representative samples were taken to the laboratory for evaluation and selected geotechnical testing. The samplers were driven into the earth materials at selected depths in the test borings using an automatic-trip, 140-pound hammer with a 30-inch free fall. The penetration resistance was obtained by counting the number of blows of the hammer required to drive the sampler, in 6-inch intervals,a to distance of 18 inches. TEST BORING GROUTING The test borings will be backfilled to the ground surface with Portland cement grout under county environmental health department inspection at the completion of drilling. Groundwater is anticipated to be on the order of 60 feet or deeper based on previous geotechnical and geologic investigations by others,and is not anticipated to be encountered during drilling and grouting of the borings. Borings encountering groundwater(if any)will be backfilled by tremie method through the inside of the hollow stem auger or tremie pipe as it is withdrawn. Test borings 30 feet or less in depth and not encountering groundwater will be backfilled by freefall methods. Fisher Geotechnical C11 and Geotechnical Engineering