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Drilling Methods BE • Before drilling began, Underground Service Alert was notified of our intent to drill so that approximate locations of underground utility lines and structures could be marked. The soil borings were started by hand-augering to a depth.of 5 feet to minimize the possibility of damaging underground utilities. The borings were drilled with a Mobile B-53 drill rig equipped with 10-inch-diameter, continuous-flight, hollow-stem augers. The augers were steam-cleaned before use in each boring to minimize cross-contamination between borings. The drill cuttings were stored at the site on and covered with plastic. Soil Sampling in Borings Soil samples for analysis and identification were collected at approximately 5-foot intervals from the borings during drilling. Soil samples were collected by advancing the boring to a point just above the sampling depth, and then driving a California-modified, split-spoon sampler containing clean brass sleeves through the hollow center of the auger into the soil. . The sampler is driven 18 inches with a standard 140-pound hammer repeatedly dropped 30 inches. The number of blows needed to drive the sampler each successive 6 inches is counted and recorded to evaluate the relative consistency of the soil. Sampling equipment was cleaned between each use with an industrial soap and clean tap water. .. The samples selected for laboratory analysis were removed from the sampler and promptly sealed in their brass sleeves with aluminum foil, plastic caps, and duct tape. The samples were labeled and promptly placed in iced storage for delivery to a laboratory certified by the State of California. . Logging of Boring Soil cuttings and samples were logged using the Unified 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 photoionization detector (or similar instrument) readings were noted in the field on the Logs of Borings. Sampling Drill Cuttings Soil samples were collected from the stockpiled soil by driving a hand-operated percussion sampler fitted with a clean brass sleeve into the stockpiled soil. The sleeve was removed from the sampler and promptly sealed with aluminum foil, plastic caps, and duct tape. The sample was then labeled and placed in iced storage. Chain of Custody Records were initiated by the geologist and accompanied the samples to the analytical laboratory. � i :l