Laserfiche WebLink
1999 The ground surface elevation of borings CPT-13 and CPT-14 were <br /> also surveyed relative to ms], and the northing and easting location of the <br /> wells, borings and other significant spots on the property were surveyed <br /> relative to the California Coordinate System The benchmark used for this <br /> survey was the USGS M1164-1960 brass cap at the southeast corner of <br /> Airport Way and West Yosemite Avenue The survey information is <br /> presented in Appendix F <br /> Depths to groundwater were measured in each well prior to sampling on <br /> May 12, 1999 with an electric water level sounder Depth to groundwater <br /> measurements are presented in Table Four, and groundwater elevation <br /> (potentiometric surface) contours are plotted on Figures 4, 5 and 6 On <br /> May 12, 1999, groundwater in the shallow zone (less than 19-feet bgs) <br /> appeared to flow to the northwest beneath the site at a gradient of <br /> between 0 008 to 001-feet/foot Potentiometric surface contours for t h e <br /> deeper zones (55 to 70-feet bgs and below 100-feet bgs) could not be <br /> plotted because three non-linear points for each zone are required for <br /> contouring However, since the potentiometric surface in monitoring well <br /> MW-7 is higher than the potentiometric surface in monitoring well MW-9 <br /> (both wells screened between 55 and 70-feet bgs) and since the <br /> potentiometric surface in monitoring well MW-8 is higher than the <br /> potentiometric surface in monitoring well MW-10 (both wells screened <br /> below 100-feet bgs), it appears that groundwater in these deeper zones <br /> may have a flow component to the south, probably being influenced by <br /> pumping from the on-site drinking water well <br /> 1 1 . 0 ANALYTICAL RESULTS FOR GROUNDWATER <br /> The groundwater samples were analyzed by Chromalab for TPH-G b y <br /> modified EPA Method 503018015, TPH-D by EPA Method 355018015, and <br /> VOCs and fuel oxygenates by EPA Method 8260 The analytical results are <br /> tabulated in Table Five and plotted on Figure 9 Copies of the certified <br /> analytical report and chain of custody form are included in Appendix G <br /> Hydrocarbons were detected in all of the groundwater samples analyzed <br /> The highest concentrations detected were in groundwater samples <br /> collected from monitoring wells MW-5 and MW-6 BTEX concentrations in <br /> groundwater samples collected from these two wells exceeded DTSC MCLS <br /> for drinking water The high total xylenes and toluene concentrations in <br /> these samples, relative to the benzene concentrations, and lack o f <br /> oxygenates in these samples suggest an older release Benzene <br /> concentrations in groundwater samples collected from monitoring wells <br /> MW-7 and MW-8 also exceeded the DTSC MCLS for drinking water <br /> Franks One Stop Report - lune 1999 <br /> -10- <br />