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(:VYATC r� A S S O C i A T E 5 I M1i C ` EPA method 8015 modified, BTEX by EPA method 8021B, and MTBE, TAME, TBA, ETBE, DIPE, 1,2-DCA, and EDB by EPA method 8260B The analytical results for groundwater samples are summarized in Table 2 Laboratory data sheets and chain-of-custody documentation are included in Appendix C On January 8, 2004, groundwater samples were collected from wells MW 1 through MW7 The samples were collected after purging a minimum of three well volumes and stabilization of electric conductivity, pH, and temperature Field purge logs are presented in Appendix D Subsequent to purging, groundwater was sampled and transferred to appropriate sample containers, using clean, disposable bailers with bottom emptying devices to reduce volatilization Groundwater samples were placed on ice and delivered under chain-of-custody documentation to Argon Laboratories for chemical analysis Groundwater samples were analyzed for TPHg by EPA method 8015 modified, BTEX by EPA method 802113, and MTBE, TAME, TBA, ETBE, DIPE, 1,2-DCA, and EDB by EPA method 8260B The analytical results for groundwater samples are summarized in Table 2 Laboratory data sheets and chain-of-custody documentation are included in Appendix C 3.0 SUBSURFACE CONDITIONS 3.1 Geoloev Soil from the borings generally consisted of silts and clays from the surface to 45 feet bgs Soil consisted of silty sand and sand from depths between 45 to 55 feet bgs Soil from the CPT boring was classified as alternating layers of stir fine grained soil, silty clay and clayey soils from approximately 5 feet to 50 feet bgs From approximately 50 to 55 feet bgs the soil was classified as cemented sand and sandy silt From approximately 55 to 100 feet the soil was classified as alternating layers of stiff fine grained soil and clayey soil Soil boring logs with a detailed description of soil types are contained in Appendix B The CPT report is contained in Appendix A 3_2 Hydrogeology Fluid levels were taken on January 8, 2004, utilizing an electronic water probe capable of measuring with an accuracy of 11100 of a foot Groundwater elevation data are presented in Table 2 Water levels ranged from 44 12 to 46 70 feet below the tops of the well casing elevations The water level data were used to develop the groundwater elevation contour map (Figure 3) Assuming that horizontal isotropic conditions prevail, groundwater in the uppermost aquifer beneath the site flowed towards the east-northeast The average hydraulic gradient on r� January 8, 2004 was calculated to be 0 0007 ft/ft or approximately 3 8 ft/mile A summary of groundwater monitoring data is presented in Table 1 SIEnviromental\224931REPORTSLsumni doe 5