ARCHIVED REPORTS_XR0003123 - Laserfiche WebLink

Home Browse Search

I MOHR-FRY Ranches 950 Industrial Drive, Stockton, California ,rune 2, 1993 Phase II Remedial Report Page. 8 the monitoring wells, water elevations and the gradient. The well elevations were ' calculated by a licensed surveyor (Appendix E) and depth readings were taken before the monitoring wells were sampled (Appendix D). The water table in all borings averaged between 50 and 51 feet. 1 Table 3 Ground Water Elevations ' Well MW-1 MW-2 MW-3 ' Elevation of Well (ft) 18 18 17.68 1783 ' Depth to Water Level (ft) -49.85 -49.56 -49.70 Elevation of Water (ft) -31.67 -31.88 -31.87 I6 0 Conclusions And Recommendations Three contaminated plumes have been defined at the Mohr-Fry site. The discontinuous I contamination plume shown on cross section B-B' (Figure 4) at drill holes B1 and MW- 2 suggests overfilling of the tanks. The contaminates migrated down to a thin discontinuous clayey sand layer, then laterally to drill hole MW-2, then continuing vertically downward to the capillary fringe. A second plume occurs at drill hole B-2 from a buried tank and is shown on cross section C-C' (Figure 5). Toluene was detected continuously from the excavation to the capillary fringe, indicating a lealang tank. A third plume occurs at drill hole MW-3 in the area of three (3) six thousand gallon surface tanks that were recently discovered to have been at this location. The tanks were reported to have contained polyester resin. Section B-B' (Figure 4) shows that � Toluene and/or Xylene was detected continuously to the capillary fringe. Drill holes B-3, B-4 and B-5 were "non detect" for all tests. The close proximity of drill holes indicate point source contamination and vertical downward inverted cones of contamination, with the exception of some lateral movement at the tank excavation at drill hole B-1 (Figure 4) i i