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=16107J_®®��® <br /> W/wA <br /> Working to Restore Nature <br /> Drilline Methods <br /> Before drilling began, Underground Service Alert was notified of our intent to drill so that <br /> approximate locations of underground utility lines and structures could be marked The soil <br /> borings were started by hand-augering to a depth of 5 feet to minimize the possibility of <br /> damaging underground utilities. <br /> The borings were drilled with a Mobile B-53 or similar drill rig equipped with 8-inch- <br /> outside-diameter by 4-1/4-inch-inside-diameter and 10-inch-outside-diameter by 6-1/4-inch- <br /> inside-diameter, continuous-flight, hollow-stem augers The augers were steam-cleaned <br /> before use in each boring to minimize cross-contamination of the borings The drill cuttings <br /> were stored in a water tight bin before disposal at an appropriate disposal facility. <br /> Soil Sampling in Borings <br /> Soil samples for analysis and identification were collected at approximately 5-foot intervals <br /> from the borings during drilling Soil samples were collected by advancing the boring to a <br /> point dust above the sampling depth, and then driving a Califorma-modified, split-spoon <br /> sampler containing clean brass sleeves through the hollow center of the auger into the soil <br /> The sampler is driven 18 inches with a standard 140-pound hammer repeatedly dropped 30 <br /> inches The number of blows needed to drive the sampler each successive 6 inches is <br /> counted and recorded to evaluate the relative consistency of the soil Sampling equipment <br /> was cleaned between each use with an industrial soap and clean tap water <br /> The samples selected for laboratory analysis were removed from the sampler and promptly <br /> sealed in their brass sleeves with aluminum foil, plastic caps, and Teflon tape The samples <br /> were labeled and promptly placed in iced storage for delivery to a laboratory certified by <br /> the State of California. <br /> Logging.of Borings <br /> Soil cuttings and samples were logged using the Unified Soil Classification System Samples <br /> not selected for chemical analysis and the soil sampler shoe are extruded in the field for <br /> examination. The texture, color, moisture, plasticity, and consistency of soil, the blow <br /> counts, and subjective evidence of hydrocarbons, such as soil staining, obvious product odor, <br /> and photoionization detector (or similar instrument) readings were noted in the field on the <br /> Logs of Borings <br /> 30003-7 <br /> r <br />