Laserfiche WebLink
04/09/98 THU 07:57 FAX GROUNDWATER <br /> .- N. <br /> I <br /> l post-it'Fax Note 7671 °ate liltrem► <br /> E <br /> i <br /> April e,1998 '10 i R� ---h o Frpm S " l <br /> Fit;110N CoJDW. _ ca- 9 <br /> Mr.Harlin Knoll Ft°a F Q `lrtc Phone d D <br /> San Joaquin County Public Health Services : Fax n , F"* $ <br /> Environmental Heatth DMWOrl ! <br /> Avenue,304 E.Weber A ,Third Floor ,a <br /> P.O,Box 388 % i <br /> Stockton.California 952010388 <br /> RE: Feasibility Evaluation for Limited Excavation vs.In-Situ Remediation Methods ` <br /> Judi Concurrent Soil/GW Extraction and Air Sparging ,I1 <br /> Including <br /> Additional Information on Remediaaiion and Post-Remediation Activities ; <br /> Southiand Store No.20304 <br /> 455 West Grant Line Road <br /> Tracy,California <br /> Site Code 1409 <br /> Dear Mr.Knoll: <br /> As requested,the following document is an addendum to Fluor Daniel GTI's January 26, 1898,Remedial Action <br /> Plan for Soil Excavation at the referenced site: <br /> E <br /> Since a Remedial Action Plan for concurrent soil vapor/groundwater extraction was previously submitted to the <br /> San Joaquin County Public Health Services Environmental Health Uwision(SJCEHD)by Harding Lawson and <br /> Associates,a brief;cost analysis Is attached to demonsUate the cost-effectiveness of the proposed alternate <br /> remediation method. This feasibility evaluation was prepared to meet State Underground Storage Tank <br /> Reimbursement Fund criteria for reimbursable remediation activities at this site_ Mr.Bob DeNinno of The <br /> Southland Corporation has authorized the revised remediation approach,and will verfir this with the SJCEHD. <br /> In addition,the SJCEHD requested specific revision of proposed field activities,including 1) reconfiguration of the ; <br /> proposed area of excavation to include additional possible hydrocarbon source areas,2)specification of the total <br /> yardage to be removed,3)reduction of the number of confirmation samples within the area of excavation,and 4) <br /> clarification as to the construction of the ptist-excavation source-area monitoring well. i <br /> i <br /> Revised Area of Eacation,Number of Samples,and Total Yardage to be Excavated <br /> r ' <br /> Attached is the proposed revised area of e"vation,based on 1986 soil hydrocarbon concentrations of 2,000 <br /> parts per million(ppm)total petroleum hydrocarbons as gasoline(TPH-g)observed during installation of well <br /> GWE-3,and 2,800 ppm TPH-g observed beneath the former pump island area. The number of confirmation <br /> samples has been reduced to include twoIsidewallsamples from each hydrocarbon source area,collected at the i <br /> upgradient(southwest)and downgradient{northeast)edges of the excavations. Two base samples will be <br /> collected in the area of excavation around well GWE-3,and one base sample will be collected from the <br /> excavation near the former pump island area. Samples will be collected,preserved,and analyzed as referenced <br /> in the January 26,'11996,Remedial Action(Plan. <br /> 1111 Based on the proposed areas shown,about 150 cubic yards of soil will be excavated. The area of excavation near <br /> well GINE-3 is about 450 square feet(equivalent to about 83 cubic yards when removed to a depth of 5 feet below <br /> grade). About 55 cubic yards is expected to be removed from the former pump island location.based on a lateral <br /> extent of about 20 by 15 feet,and a vertical extent of 5 feet below grade. Based on field observations of relative <br /> hydrocarbon content,the SJCEHD may request additional excavation in the areas shown,but total yardage is <br /> expected to not exceed 200 cubic yards. :! i <br /> 757 Arnold Drive,Suite D/Ntarrir ez,CA 94553 USA (510)370-3990 FAX(510)370-3991 <br /> t <br /> i <br /> �i <br /> 4 <br />