ARCHIVED REPORTS_XR0010148 - Laserfiche WebLink

Home Browse Search

I Former Canteen Facility Apnl 7,2003 Iquarterly Groundwater Monitoring Report Page 3 GROUNDWATER CONDITIONS IThe following summarizes the local groundwater gradient and the groundwater analytical results Groundwater Gradient Interpretation of the monitor well gauging data indicates that there is a west - I southwesterly hydraulic gradient across the Site of approximately 0 0017 feet/foot Figure 2 illustrates the groundwater contours and gradient for this gauging event The gradient appears to be consistent with past gauging events The change in water levels is a result of cyclical fluctuations in the weather and the proximity of the site to the Stockton Diverting Canal, located approximately 1000 feet to the northeast The historical groundwater elevations are summarized on Table 1 IGroundwater Analytical_Results Groundwater analytical results are compared to the California Department of Health Services Drinking Water Standard Maximum Contaminant Levels (CAMCL) Analysis of the groundwater samples obtained from the seven Site monitor wells indicated the following • Benzene was detected in groundwater samples from monitor wells MW-3, MW- 3D, and MW-13 at concentrations of 3 5, 28, and 16,000 µg/l, respectively The groundwater samples taken from all three monitor wells exceeded the CAMCL for benzene of 1 0 µg/l • Toluene was detected in monitor wells MW-31), MW-13, and MW-13A, at concentrations of 1 5, 26,000, and 0 55 µg/l, respectively The CAMCL for toluene is 150 µg/l, exceeded only in MW-13 • Ethylbenzene was detected in monitor wells MW-3A, MW-3D, and MW-13 at concentrations of 15, 37, and 1,200 µg/l, respectively The CAMCL for ethylbenzene is 700 Fig/l, exceeded only in MW-13 ' • Tota 1 xylenes were detected in monitor wells MW-3D and MW-13 at concentrations of 7 0 and 14,000 µg/l, respectively The CAMCL for xylenes is I1,750 µg/L, exceeded only in MW-13 REGU� 4�OO.t 2 L/C£5~