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i <br /> 21 May 2003 <br /> • AGE-NC Project No 95-0130 <br /> Page 11 of 16 <br /> I4 2 1 Drilling And Soil Sample Collection <br /> Soil borings for Installation of two ground water extraction wells (EW-1 and EW-2) will be <br /> advanced to a depth of 55 feet bsg utilizing a truck-mounted, hollow-stern drill rig and 15-inch <br /> diameter hollow-stem augers Soil cuttings will be placed and covered in a 20 yard, metal soil bin <br /> located in a southwest portion of the site, nnseate generated during drilling activities will be <br /> containerized in properly labeled DOT-approved 55-gallon drums, and stored in an area on the site <br /> lacking public access Disposal alternatives for nnseate and stockpiled soil will be selected based <br /> on results of a laboratory analysis <br /> During drilling, soil samples will be collected at five-foot intervals for logging purposes, selected <br /> soil samples will be analyzed by a State of California Department of Health Services(DHS)-certified <br /> laboratory for the following constituents <br /> • TPH-g in accordance with EPA Method 8015 Modified/5030, <br />' • BTEX compounds by EPA Method 8020, <br /> • 1,2-DCA,EDB,MTBE,TAME,DIPE,ETBE and TBA by EPA Method 8260 Modified,and <br />' • • Total lead by EPA Method 7420 <br /> I Laboratory reports for soil analysis, testing methods, laboratory quality assurance/quality control <br /> (QA/QC) reports, and sample chain of custody documentation will be presented in a report with <br /> findings and recommendations <br /> I <br /> 4 2 2 Ground Water Extraction Well Completion <br />' round water extraction wells EW-1 and E-2 will be completed utilizing a single 6-inch diameter <br /> G P g g <br /> schedule 40 polyvinylchloride (PVC)well casing with 20 feet of 0 030-inch slotted well screen, a <br /> Iproposed well construction diagram is depicted in Figure 9 <br />' After installing the well casing in each boring,a filter pack material will be slowly emplaced through <br /> the augers over the screen interval to approximately two feet above the screened intervals,filter pack <br /> material will consist of a 50150 blend of pre-washed small-grained aquarium gravel and#3 Lonestar <br />' sand Following placement of the filter pack,the screened interval from each well will be surged for <br /> approximately 20-30 minutes utilizing a surge block to assist in settling the filter pack Additional <br /> filter pack material will be added if settling occurs <br /> A nominal three-foot bentomte seal (bentonite chips) will be placed above the filter pack to <br /> . minimize the potential for grout penetration into the screened section of the well The bentonite seal <br /> Advanced GeoEnviron mental,Inc <br />