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Ms. Connie Davis/Aggregate lndus[ries - F Street October 2001 QMR Project Number [001018 PnxncoN November 16, 2001 Page 3 are provided on the boring log attached to this report. Afield log was prepared by Paragon the field engineer. The log contains visual and tactual classifications of the materials encountered during drilling, as well as the driller's interpretation of subsurface conditions based on drilling resistance. The description of the soils encountered in the borings are in general accordance with the General Notes attached to this letter. A final boring log for MW-5 included with this letter represents an interpretation of the field log. The stratification boundaries shown on the enclosed boring log represents the approximate locations of changes in soil types; in-situ, the transition of materials may be gradual. 3. GEOHYDROLOGY Groundwater elevations in wells MW-1 through MW-5 and EW-1 were measured by Paragon prior to sampling on October 18, 2001. Groundwater elevation data for the site is summarized in Table 1 which is attached to this report. As seen from Table 1, groundwater wa:; observed at depths ranging from approximately 5.9 to 24.2 feet below grade during the October 2001 sampling event. Free-phase product was not observed during the October 2001 sampling episode. Piezometric surface diagrams for groundwater elevations observed on October 18, 2001 are attached to this report as Figures 3 and 3a. The piezometric surface for the overall site, including wells OW-1 through OW-3, is shown on Figure 3 while the piezometric surface in the vicinity of the spill area is shown on Figure 3a. The piezometric surfaces were estimated using the computer program Surfer° which is distributed by Golden Software. As seen from Figure 3, the regional groundwater flow generally appears to be in a northeasterly direction with a more northerly component on the east side of the site. As seen from Figure 3a, the local groundwater flow direction appears to be to the northeast in the vicinity of the spill area with a more northerly component east of the spill area. The hydraulic gradient was estimated to range from approximately 0.009 to 0.02 for the overall site while the hydraulic gradient was estimated to range from approximately 0.002 to 0.006 for the spill area. It should be noted that local geohydrologic characteristics such as flow direction and gradient may change due to variations in precipitation and recharge or other conditions not evident at the time of field exploration. 4. GROUNDWATER QUALITY RESULTS Information collected during the October 2001 quarterly sampling events relative to groundwater quality at the site is summarized below. That information includes