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Geologcral Taves Inc Page 2 <br /> Groundwater Monitoring Report <br /> Project No 662 2 <br /> October 3,2002 <br /> 1.0 GROUNDWATER MONITORING <br /> 1.1 Hydrogeology of Site <br /> ' The dominant soil type in the upper 40 feet of subsurface geologic soils investigated is fine <br /> to course grained sand alternating with thinner beds of plastic clay The average <br /> groundwater elevation on July 17, 2002 was approximately 13 43 feet above MSL, which is <br /> ' about 25 feet below ground surface <br /> A groundwater gradient was calculated for the event and the groundwater was found to flow <br /> ' N87°F at 0 0053 ft/ft Groundwater elevation and gradient data are summarized in Table 1, <br /> Appendix A Gradient direction is shown on Figure 2 Gradient Map, and Figure 3 <br /> Groundwater Gradient Rose Diagram <br /> 1.2 Groundwater Sampling Procedure <br /> ' On July 17, 2002, Don Light of Del-Tech mobilized to the site to conduct a groundwater <br /> monitoring of the four monitoring wells on site <br /> Before sampling was performed the wells were sounded for depth to water and then a clear <br /> disposable bailer was used to determine if floating product was present The wells were <br /> purged of at least three well volumes of stagnant water using a dedicated Waterra check-ball <br /> ' assembly and '/2 inch tubing Purging continued until the temperature, conductivity, and pH <br /> of the groundwater stabilized (<10% variation between three readings) indicating that <br /> ' formation water representative of aquifer conditions was entering the wells These water <br /> quality parameters were measured at intervals of each well volume purged <br /> Once purging was complete, a water sample was collected from the Waterra tube Care was <br /> taken to minimize sample agitation Once the sample container was filled and capped, the <br /> bottle was inverted, tapped, and checked for headspace bubbles The sample container was <br /> ' identified and labeled with a unique designation, inserted into foam holders and placed in an <br /> ice chest cooled to 4°C for transport to the laboratory <br /> ' <br /> All non-disposable sampling equipment was decontaminated using a hot water washer and <br /> detergent before and between uses Disposable gloves were used by the technician to <br /> collect all samples and were changed with each sample collection <br /> A chain of custody document, listing all samples collected, accompanied the samples from <br /> field to laboratory, thereby providing a means to track their movement and insure their <br /> integrity <br />