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1 <br /> CealogiraC'IecFrnrrs 2nc. ,,, Paae 3 <br /> soil Baring and Monitoring Well Installation Work Plan b <br /> Former Moresco Property <br /> Project No.251.2 <br /> November 4, 1998 <br /> The OVM is a portable photo ionization detector that,uses a 10.0' eV lamp to detect <br /> compounds with ionization potential below 10.0.eV (hydrocarbon range). <br /> 2.1.2 Soil Laboratory Analyses <br /> Based on field screening observations and geologic classifications, soil samples from each <br /> significant geologic interval will be submitted to BSK Laboratories of Fresno (State Certified <br /> Laboratory # 1180). These samples will be t analyzed for <br /> • Benzene, Toluene, Ethylbenzene and Xylene (BTEX) by EPA method 8020, <br /> • Gasoline range petroleum hydrocarbons (TPH-G) by EPA method 801.5(m) <br /> • Methyl Tertiary Butyl Ether(MTBE) by EPA method 8'020 with confirmation by 8260 <br /> The detection limits for these compounds are listed below. .A Chain of Custody will be <br /> completed for all samples collected and tracked-to ensure sample.integrity. <br /> i <br /> etection emits: aso me <br /> of P Kg .. <br /> , <br /> Value in.paren esis is detection by method-926(Y-- <br /> 2.1.3 <br /> e o2.1.3 Monitoring Well Construction <br /> The monitoring well will be constructed. using 4.0-inch„diameter PVC casing with flush <br /> threads. The length and slot size of the screened interval will be determined in the field. <br /> Groundwater is expected to be located approximately I I0'feet below grade. A sand filter <br /> pack will.surround and extend two feet above the-screened;interval. Sand size will also be <br /> determined in the field according to the geology and slot size of the well. A granular <br /> bentonite transition seal will be installed and hydrated. A surface.seal will be achieved by <br /> pumping a neat cement grout (augmented with < 4% bentonite) via a tremie tube. The well <br /> will be secured with a locking watertight cap encased in flush mounted traffic rated well box. <br /> After the well sealing materials have set (>24 hours) the well will be developed (using <br /> mechanical surging and pumping methods) until a clear stream of water is obtained. The 1 <br /> well will-be purged and groundwater samples collected_ no:sooner than 48 hours after well <br /> development. All development and purge water will be`l containerized in 55-gallon DOT t <br /> approved containers and stored on site until their disposition can be arranged. <br /> 2.2 Groundwater Sampling Procedure <br /> I <br /> Thegroundwater in the new well will be sampled no ':sooner than 48 hours after well <br /> development and again six weeks later. The following is: a. procedure for the sampling of <br /> groundwater from the well: <br /> Before sampling is attempted the well will be sounded for;depth to water and then a clear <br /> disposable bailer will be used to determine if floating product is present. The well will be <br /> purged of at least 3 well.volumes of stagnant water using either a submersible pump or a <br /> stainless steel bailer. Purging will continue until the temperature, conductivity, and pH of the <br /> groundwater has stabilized (<I 0%variation between three readings) indicating that formation <br /> water representative of aquifer conditions is entering ':the well. These water quality <br /> parameters are measured at intervals of each well volume purged. <br /> A stainless steel or disposable plastic bailer will be used to,collect each sample. Care will be <br /> taken to minimize sample agitation from the,initial filling'of the bailer to the transfer of the <br />