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Geolagual T"k sks 19c Page 4 Groundwater Monitoring Report Project No 770 2 February 7,2005 ' Before sampling was attempted the wells were sounded for depth to water and then a clear disposable bailer was used to determine if floating product was present The recharge was poor in wells MW-5, MW-6, MW-7, and MW-8 However, other wells were purged of at least three well volumes of stagnant water using a dedicated Waters check-ball assembly and V2 inch tubing Purging continued until the temperature, conductivity and pH of the ' groundwater stabilized (c10% variation among three readings) indicating that formation water representative of aquifer conditions was entering the wells These water quality parameters were measured at intervals of each well volume purged Once purging was complete, a water sample was collected from the Waterra tube (we]is MW- 5 and MW-7 were sampled/bailed with a stainless steel or disposable Teflon bailer due to ' poor recharge) Care was taken to mimnuze sample agitation Once the sample container was filled and capped, the bottle was inverted, tapped and checked for headspace bubbles The sample container was identified and labeled with a unique designation, inserted into ' foam holders and placed into an ice chest cooled to 4°C for transport to the laboratory All non-disposable sampling equipment was decontaminated using a hot water washer and ' detergent before and between uses Disposable gloves were used by the technician to collect all samples and were changed with each sample collection A chain of custody document, listing all samples collected, accompanied the samples from field to laboratory, thereby providing a means to track their movement and insure their integrity All water purged from each monitoring well and not used as a sample was laced in P g g P P a properly labeled 55 gallon DOT approved container and stored on site until its proper disposition can be arranged ' Groundwater monitoring field logs are included in Appendix C 1.3 Laboratory Analyses ' The groundwater samples collected on December 09, 2004, were delivered to Sequoia Analytical Lab (CA ELAP Certificate No--1624),-of Sacramento, California, for analysis ' Sequoia analyzed the eleven monitoring well groundwater samples for • Benzene, Toluene, Ethyl Benzene, and Xylene (BTEX) by EPA method 8020 • Total Petroleum Hydrocarbons as Gasoline (TPH-G) by EPA method 5030/8015(M) • TEPH-Diesel by EPA method 3500/8015(M) • 1,2 DCA and EDB by EPA method 8260 The detection limits for the above analyses are listed in Table X of Appendix A while the laboratory analytical results are presented in Appendix B ly�'`S 1