Laserfiche WebLink
November 12, 1992 Working To Restore Nature <br /> ARCO Station No 6100, Tracy, California <br /> ADDENDUM TO WORK PLAN <br /> Based on the results of this and previous investigations, and at ARCO's request, RESNA <br /> will perform the following work after the appropriate permits have been obtained <br /> o Drilling two borings southwest and northwest of boring B-25 to complete delineation <br /> of the lateral extent of residual gasoline hydrocarbons at the site <br /> o Contract with a licensed drilling company to drill two borings southwest and <br /> northwest of boring B-25 to delineate the lateral extent of residual gasoline <br /> hydrocarbons at the site The proposed boring locations are shown on Plate 2 We <br /> will collect soil samples from the borings for laboratory analyses <br /> o Construct 4-inch-diameter vapor-extraction wells in the two borings (if necessary) to <br /> remediate soil affected by gasoline hydrocarbons, if field conditions indicate that <br /> hydrocarbons are present <br /> o Drill one boring in the immediate vicinity of B-25 for the purposes of constructing <br /> a vapor-extraction well with a screened zone from approximately 15 - 45 feet bgs <br /> o Analyze soil samples from the borings for TPHg and BTEX in a laboratory certified <br /> by the State of California <br /> o Interpret the field and laboratory data to evaluate whether additional work is needed <br /> to delineate residual gasoline hydrocarbons in soil beneath the site and south of the <br /> site. <br /> o Prepare a Preliminary Investigation and Evaluation Report after the lateral extent <br /> of residual gasoline hydrocarbons in soil has been delineated If residual <br /> hydrocarbons have not been delineated, we will prepare a status report describing <br /> our findings and recommendations <br /> The work described in this addendum will be performed according to the methods and <br /> procedures described in RESNA's Work Plan No. 30041-2W, dated August 5, 1991, and <br /> prepared using the Central Valley Regtonal Board Staff Recommendations for Initial <br /> Evaluation and Investigation of Underground Tanks (Tri-Regional Recommendations), <br /> Appendix A of the Tri-Regional Recommendations, and the Leaking Underground Fuel <br /> Tank Manual (LUFT) as references The methods for installation and construction of <br /> vapor-extraction wells are described in the attached Field Procedures Remediation of soil <br /> 0623ceat <br /> 30041-3 5 <br />