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t1relented ar the VM Natioaai Outdoor Action Coa::ren_e,Las Veg=_Nevada 2day 1995 <br /> Enviro-Core®—A New Direct-Push Technology for <br /> Collecting Continuous Soil Cores <br /> ' Murray D. Einarson, C.E.G. <br /> Eiriarson Geoscience, Inc <br /> Palo Alto, California <br /> Abstract <br /> Enviro-Cores is a new direct-push system for quickly collecting continuous soil cores in <br /> unconsolidated sediments. Unlike conventional drilling techniques, no drill cuttings axe <br /> generated with the Enviro-Core,system, eliminating the expense of waste soil disposal or <br /> treatment. The Enviro-Care system consists of 2 4-inch-diameter dnve casing and an knner <br /> sample barrel that are simultaneously pushed, driven, or vibrated into the ground <br /> Continuous soil cores are collected in stainless steel liners inside the inner sample barrel After <br /> being advanced three feet, the inner sample barrel is retrieved,while the dnve casing is left iii <br /> place to prevent the borehole from collapsing The drive casing ensures that subsequent soil <br /> samples are collected from the targeted interval,rather than potentially-contaminated slough <br /> from higher up in the borehole After retrieving the inner sample barrel, the sample liners are <br /> removed for chemical analysis or lithologic identification. A new three-foot inter barrel, fitted <br /> with stainless steel liners, is quickly lowered to the bottom of the borehole An additional three- <br /> foot section of Enviro-Core drive casing is attached at the sum-face, and the process is repeated <br /> until the desired depth is reached <br /> ' The Enviro-Cora system is also used to collect soil gas and grab groundwater samples Once the <br /> target zone has been penetrated,the drive casing can be pulled back to expose the desired interval <br /> of the borehole wall, and soil vapor samples are extracted with a vacuum pump Similarly, once <br /> ' a water-bearing zone has been penetrated,the drive casing can be withdrawn slightly, allowing <br /> groundwater to flow into the casing Groundwater samples are then collected with a penstaltic <br /> pump, check-valve tubing pump, or small-diameter bailer <br /> The use of small-diameter drive casing facilitates in situ hydraulic testing, geophysical logo ng, <br /> and installation of small-diameter piezometers,monitoring points, air sparging points, and SVE <br /> ' points The Enviro-Core drive casing may also provide a way to selectively fracture <br /> contaminated fine-grained strata in order to improve the effectiveness of many in situ <br /> remediation techniques. <br /> The Enviro-Core system was used to characterize a LUFT site in Redwood City, California Use <br /> of the Enviro-Core system, in conjunction with a mobile lab and on-site data evaluation,resulted <br /> m a thorough characterization of the site geology, hydrogeology, and nature and extent of <br /> contamination in dust two days. <br /> I <br /> 1 <br />