Laserfiche WebLink
January 7, 1993 Working To Restore Nature <br /> ARCO Station No 760, Lodi, California <br /> Soil cuttings generated during drilling were stored onsite on and covered with plastic <br /> sheeting If possible, drill cuttings exhibiting subjective evidence of hydrocarbons or <br /> producing a positive response on the PID were separated from those drill cuttings exhibiting <br /> no subjective evidence of hydrocarbons. Four soil samples were collected from drill cuttings <br /> and composited into one sample at the laboratory to evaluate disposal options for the soil <br /> Borings not converted to wells were backfilled to surface with a slurry of cement, bentonite, <br /> and water. <br /> i Construction of Vapor-Extraction Wells <br /> Vapor-extraction wells were constructed of thread pointed, 4-inch-diameter schedule <br /> polyvinyl chloride (PVC) casing No chemical cements, glues, or solvents were used in well <br /> construction The screened portion of the wells consists of factory-perforated casing with <br /> i 0 10-inch-wide slots A maximum interval of 25 feet of slotted casings was used Pea gravel <br /> was placed in the annular space opposite the screen to approximately 1 foot above the top <br /> of the slotted casing A 2-foot bentonite plug was placed above the sand pack, and a <br /> cement-bentonite slurry was used to fill the remaining annulus to the surface A traffic- <br /> rated cast-aluminum utility box with a PVC apron was placed over each wellhead and set <br /> in concrete flush with the surrounding concrete pad This box has a watertight seal to <br /> 5 protect against surface water infiltration and is opened with a special wrench The design <br /> of the box discourages vandalism and reduces the possibility of accidental disturbance of the <br /> well <br /> After the appropriate local and State environmental agencies indicate that remediation of <br /> soil is no longer required, the vapor-extraction wells will be removed A drill rig is used to <br /> remove the casing and gravel pack, and the bore hole is backfilled with grout composed of <br /> cement and bentonite from the bottom of the hole to surface grade <br /> r <br /> } 0820ccar <br /> 38048-7 <br />