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5' April 24,1989 File Na.1705-2 f Depth to Water, ft, (1/31./89) (3/3/89) IM-1. 45.25 44.50 MW-2 45.25 44.30 MW-3 45.50 44.60 NO clear indication of the direction of groundwater flow in the shallow groundwater system could be determined from available data. Due to the very flat nature of the surface topography and the sediments, and the nearly identical depths at which groundwater is present in the wells, it is apparent that little indication of the overall groundwater flow gradient could be derived from these closely spaced wells. Over time, and with wel.head elevations for these wells, and possibly others, an indication of the local flow direction and gradient may be possible. A factor which may drastically affect the direction of flow in the subsurface is the presence of the large diameter pumping wells south and east of the site. Identified in i the "Preliminary Aepore', these wells may produce significant quantities of water during peak demand months and remain dormant at other times. The local groundwater regime, therefore, may be affected by these wells seasonally and on a day-to-day basis. With significant drawdown created in the shallow groundwater around these wells, the flow direction at the site would be towards the south to southeast. If no pumpi occurs, an equilibrium condition may develop withgroundwater flow towards the local base level, probably the Deep Water Channel area to the west. Well construction details, aquifer interconnection, exact distance from these wells and water withdrawals are j clearly needed if any evaluation of the effects of these wells is to be made. Little data were available to us for the preparation of this report regarding groundwater quality. The information available suggests that groundwater is generally usable from the standpoint of general mineral characteristics. In one well located approximately 150 yards east of the subject site, total dissolved solids content measured approximately 1000 mg/l (milligrams per liter) However, organic solvents above drinking water stand- ards were found in this well. Also, the benzene and other fuel constituent levels in all on-site wells exceeds acceptable drinking water standards. exhibited organic-campo��ds ;n rhe water. hiW 2 had a benzene concentration of 6.08 mg/l, toluene and 11.7 mg/1 and xylene at 13.0 mg/l. MW-1 and MW-3 had traces (ug/l or ppb) of benzene and other fuel constituents revealed in the groundwater. 2