ARCHIVED REPORTS_XR0007343 CASE 2

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• RMC Pacific Materials; Kerhnger Aggregate PIant Initial Quarterly Sampling Report 30350 South Tracy Boulevard, Tracy, CA. San Joaquin County Site #1737 INTRODUCTION This report presents the results of the Second Quarter groundwater-sampling event undertaken by RMC Pacific Materials (RMC) at the above-referenced property on November 17, 2003 in accordance with our sampling requirement The report describes the sampling protocol used to sample the wells and results of laboratory analyses on the samples SAMPLING PROTOCOL The sampling process began by obtaining depth-to-water measurements (Table 1 and Figure 1) in each of the three-groundwater monitoring wells with an electronic water tape These measurements were recorded and used to calculate the volume of water in each well No evidence of immiscible liquid was observed on the water tape during the measurement of the any of the wells Each well was then purged of three casing volumes of water using the dedicated bladder pumps that were installed in May 2003 Field readings were taken at approximately three-gallon intervals to monitor the pH, temperature and conductivity of the extracted water Copies of the field sheets used to record all field data are included in Appendix B Once the desired volume was extracted from the well a set of groundwater samples were collected into laboratory-supplied 40-m1 VOA vials and one-liter amber glass sample bottles All sample containers were properly labeled and immediately placed into a cool icechest for subsequent analysis at Severn Trent Laboratory (STL) in Pleasanton, CA Proper chain-of-custody protocol was maintained at all times The depth-to-water measurements were also used to determine if the groundwater table gradient between the wells had changed since the wells were developed in February 2003 These new measurements confirmed that the water table continues to slope toward the north at a gradient of approximately one foot per six hundred feet (Figure 3) RESULTS OF ANALYSES Ground water samples collected from each well were analyzed for TPH-diesel (EPA method 8015M) and BTEX (EPA method 802113) Laboratory analyses indicate that the BTEX concentrations were non-detect in each of the three wells and diesel concentrations were non- detect in the two monitoring wells nearest to the former asphalt plant (MW 4 and 5) The analyses indicate, however, that a diesel concentration of 89 µg/L apparently exists in MW 6 RMC has contacted STL to reanalyze the sample to confirm the results The results of all analysis are presented in Tablel A copy of the laboratory report and the chain-of-custody record is included in Appendix A