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SITE CONTAMINATION WORKPLAN <br /> AND <br /> SOIL REMEDIATION PLAN <br /> INTRODUCTION <br /> PG&E plans to remove a 2,000 gallon underground diesel tank <br /> on or around (Date) . This SCW/SRP has been prepared as a <br /> contingency plan in the event low levels of petroleum range <br /> hydrocarbons are encountered in the soil two feet below the <br /> tank. This contingency plan establishes procedures for <br /> evaluating and disposing of affected soils in order to <br /> remediate the site in a timely and cost effective manner. <br /> SITE HISTORY <br /> On October 16, 1991, a 12,000 and two 5, 000 gallon unleaded <br /> fuel tanks were removed. Soil samples were obtained in <br /> accordances with all the San Joaquin County Environmental <br /> Health Department guidelines. Due to the low levels of <br /> petroleum range hydrocarbons present in the initial samples a <br /> SCW and a PAR were developed by Dames and Moore. The SCW and <br /> the PAR were approved by the County and the existing <br /> excavation was further excavated by five feet. Confirmation <br /> samples were taken and the results were negative. The <br /> excavation was then back filled with clean fill and paved. <br /> The new tanks were installed adjacent to the original <br /> excavation. <br /> The 2, 000 gallon diesel tank that will now be removed has <br /> been in operation for over 20 years and has experienced no <br /> major problems to date. The results of the last annual <br /> precision test (performed on February 2 , 1991, see <br /> attached copy) were acceptable. The tank is continually <br /> monitored by a TLS-250 system. Groundwater is estimated at <br /> 60 feet. <br /> PURPOSE AND SCOPE OF WORK <br /> The purpose of this investigation will be to analyze and <br /> evaluate subsurface soils for petroleum range hydrocarbons in <br /> accordance with the criteria specified in the Regional Board <br /> Staff Recommendations for an Initial Evaluation and <br /> Investigation of Underground Tanks , Appendix A, Tri-Regional <br /> Recommendations. As stated earlier, this report is a <br /> contingency plan in the event that there are obvious signs of <br /> hydrocarbon constituents in the soil two feet below the tank. <br /> If this condition exists, we propose, in accordance with the <br /> Tri-Regional Recommendation, to address the areas of concern <br /> by performing a "scoop and run" cleanup. In essence, to <br /> further excavate the pit by five feet and take confirmation <br /> samples below the two initial samples required by the Tri- <br />