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c • Table 1 Monitoring Well Water Levels, con't Well Date Well Depth to Casing Water Floating No Sampled Depth% Water Elev Elev Product (ft) (ft) (MSL ft)" (MSL ft) MW-74 8120197 1495 782 4878 4096 None MW-7^ 12/12/97 1495 784 — 4094 None MW-7^ 3/31198 1304 708 ---- 4167 None MW-7^ 6/30198 1305 709 — 4169 None MW-7^ 9129/98 1305 839 ----- 4039 None MW-8^ 8120/97 1600 796 4790 3994 None MW-8^ 12/12/97 1600 757 ---- 4033 None MW-8^ 3/31/98 1456 6 79 --- 41 11 None MW-8^ 6/30198 1451 679 — 4095 None MW-8^ 9/29/98 1458 824 ----- 3956 None MW-9^ 8/20197 1595 833 4828 3995 None MW-9^ 12/12/97 1595 800 — 4028 None MW-9^ 3/31/98 13 18 723 ----- 41 05 None MW-9" 6130198 13 18 749 — 41 79 None MW-9^ 9129/98 13 18 876 — 3952 None *Casing elevation data from EVAX Technologies, Site Investigation Report, April 7, 1992 " Casing elevation data from Triple"E" Engineering and Surveying, August 14, 1997 • %Well depth measured to observe for long term well silting The sampler removed purge well volumes of groundwater using a submersible electric purging pump (a volume calculation was done for each well following sounding measurements) Between each well volume purge, conductivity, pH, and water temperature readings were obtained and noted on the attached groundwater sampling information sheets Once these readings stabilized after two consecutive purge volumes aquifer water is assumed to be entering the well When the well recovered to about 80% of the initial water level, the sample was collected Purge water was stored on-site in drums The field well sampling information sheets containing temperature, conductivity, pH, depth to water, and well volume data purged are attached The groundwater sample was collected with a new disposable bailer The groundwater sample was then poured with minimum cavitation into the appropriate, laboratory prepared sample containers leaving no headspace The sample container was then immediately capped, labeled and placed in a chilled ice chest for shipment to Chromalab, Inc in Pleasanton, California (a State Certified Testing Lab) under chain-of-custody Groundwater Contour Map and Flow Gradient A groundwater contour map to a known datum was prepared for the data lasted in Table 1 above (see Figure 1) The groundwater flow direction was to the northerly under a calculated gradient of 0 0031 and is consistent with historic observed trends Overall groundwater levels appear to have declined about 1 7 feet from the previous quarter The large groundwater mound at MW-9 in the previously quarter has disappeared MW-9 is very near an agricultural line and periodic leakage from either that pipeline or another subsurface water source may occur nearby Page 3