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r September 15, 1993 Working To Restore Nature Ruiz Grocery, 'Tracy, California Lonna of Borings Soil cuttings and samples are logged using the Urufied Soil Classification System Samples not selected for chemical analysis and the soil sampler shoe are extruded in the field for examination. The texture, color, moisture, plasticity, and consistency of soil, the blow counts, and subjective evidence of hydrocarbons, such as soil staining, obvious product odor, and photolonizatlon detector (or similar instrument) readings are noted in the field on the Logs of Borings. Water Sampling_With a Hydropunch A CME 55 or similar drill rig equipped with 8-inch-outside-diameter by 4-1/4-inch-inside- diameter hollow-stem augers is used to drill borings to approximately 3 feet into first encountered groundwater After the auger is terminated in groundwater a Hydropunch ` sampling device is driven into groundwater and the auger 1s pulled up to the top of groundwater Groundwater samples are then collected from the Hydropunch sampling device The water samples are handled and transported to a State-certified laboratory as described in that section of the Field Procedures, analytical results are used to confirm the placement of the monitoring wells. SamplingofDrill Cuttings Soil samples are collected from the stockpiled drill cuttings by driving a hand-operated percussion sampler fitted with a clean brass sleeve into the stockpiled soil The sleeve is removed from the sampler and promptly sealed with aluminum foil, plastic caps, and duct tape The sample 1s then labeled and placed in iced storage Chain of Custody Records are initiated by the geologist and accompany the samples to the analytical laboratory Disposal of the drill cuttings at an appropriate disposal facility is the responsibility of the client Vapor-Extraction Well Construction Vapor-extraction wells are constructed using clean 4-inch-inner-diameter, thread-jointed, Schedule 40 polyvinyl chloride (PVC) casing The screened portion of the vapor-extraction well consists of 5- and 10-foot sections of factory-perforated casing with 0 1-inch slots Unperforated casing is set from the top of the screen to several inches below surface grade The annular space of each well 1s packed with pea gravel from the bottom of the screen portion to approximately 1 foot above the top of the screen A plug of bentonite pellets (approximately 2 feet thick) are placed above the sand to prevent cement from entering the sand pack. The remaining annulus is backfilled to the ground surface with a mixture of water, cement, and bentonite The construction details of the individual wells are shown on . the Logs of Borings 123020-IW