ARCHIVED REPORTS_XR0012799 CASE 2

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RMC Pacific Materials; Kerlinger Aggregate Plant Initial Quarterly Sampling Report 30350 South Tracy Boulevard, Tracy, CA. San Joaquin County Site#1737 INTRODUCTION This report presents the results of a recent groundwater-sampling event undertaken by RMC Pacific Materials (RMC) at the above-referenced property undertaken on July 16 and 17, 2003 in accordance with our current quarterly 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 used to calculate the volume of water in the well No evidence of immiscible liquid was observed on the water tape during the measurement 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 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 plastic 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 slopes toward the north at a gradient of approximately one foot per six hundred feet (Figure 3) RESULTS OF ANALYSES All water samples collected were analyzed for TPH-diesel (EPA method 8015M) and BTEX (EPA method 8021 B) Laboratory analyses indicate that the diesel and BTEX concentrations were non-detect in each of the three wells The results of analysis are presented in Tablet A copy of the laboratory report and the cham-of-custody record is included in Appendix A CONCLUSION Laboratory analyses of this latest set of water samples indicate that the local groundwater has not been affected by the petroleum contamination that was found in the surface soil layers during the . installation of the wells This finding supports the results of the previous set of water samples analyzed by STL in February