Laserfiche WebLink
Stantec <br /> L & M OPERABLE UNIT- FOURTH QUARTER AND ANNUAL 2012 SITE STATUS, <br /> REMEDIAL SUMMARY, AND GROUNDWATER MONITORING REPORT <br /> Groundwater Monitoring and Sampling <br /> February 1, 2013 <br /> during 4Q12 in the C-Zone was calculated to the northeast with an approximate hydraulic <br /> gradient of 0.003 ft/ft (Figure 17). Historical groundwater flow direction and gradient data are <br /> summarized in Table 5, and vertical gradients summarized in Table 6. The C-Zone <br /> groundwater elevation contour map for the October 15, 2012 monitoring event is included as <br /> Figure 17. <br /> 2.5.2 C-Zone Groundwater Quality Data <br /> During 4Q12, groundwater samples were collected from seven C-Zone wells between October <br /> 15 and 17, 2012 (Table 1). Groundwater analytical results are presented in Table 4, and <br /> summarized below. TPHg, TPHd, TPHo, benzene, MtBE, and TBA isoconcentration contour <br /> maps are included as Figures 18 through 23, respectively. The certified laboratory analytical <br /> reports for the groundwater sampling event conducted for the L&M OU are included in <br /> Appendix E. <br /> 2.5.2.1 Separate Phase Hydrocarbons <br /> During 4Q12, measurable SPH or SPH-sheen was not observed in any C-Zone wells. <br /> 2.5.2.2 Petroleum Hydrocarbons and Fuel Oxygenates <br /> TPHg, TPHd, TPHo, and fuel oxygenates with concentrations at or above the MRLs are <br /> summarized below. <br /> I:\Tidewater\TW Stockton(P2A)\QMRs\2012\4Q12-Ann ual\4Q12 and Annual QSSR QRSR QMR Stockton_FINAL.doc 2.8 <br />