SITE INFORMATION AND CORRESPONDENCE

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corporation 194 1 41 Member of The IT Group Mr. Marcus Pierce 2 December 5, 2000 projected aquitard intervals of 40 ft. to 50 ft. and 73 ft. to 87 ft. below ground surface (bgs). The shot strings would have been tremie-covered with neat cement grout, which would have flowed through the casing perforations into the formation immediately after the shot strings were detonated. The rationale for grout contact with formation materials at the aquitard intervals was to provide a"seal" at the aquitard intervals, which would ensure that the A- and B-aquifers remain separated from each other. This would greatly reduce the potential for vertical migration of chemicals in groundwater near the well bore, which terminates near the base of the A-aquifer zone. After review of nearby hydrogeologic and water quality information, IT now believes that it is technically justified that the A- and B-aquifers do not need to remain separated in this area. To assist in this justification, in conjunction with the attached Cross Section A-A', the boring logs for M-5A and M-5B are attached. Also, a 3 part per billion(ppb) WE isoconcentration contour map for the A-, B- and C-aquifers is attached. This contour map shows the locations of newly- installed well clusters and also provides the Cross Section A-A' index. As seen on the contour map, the new M-5C1/C2 well pair is located about 200 feet to the north of the 233 Parallel Avenue well. As seen on Cross Section A-A', the e-log for this well pair shows that there is an approximate 15-foot aquitard separating the B-aquifer from the A-aquifer, and that the A-aquifer is approximately 60 feet thick, terminating at approximately 100 feet bgs. However, at the Nestle property and to the west and north of that property, the stratigraphy indicates that there is likely a high degree of interconnectivity between the B- and A-aquifers. This is demonstrated by the boring log for the M-10 cluster and the boring log and a-log for the M-25C1/C2 well pair, which indicate finely interbedded sands, silts and clays in these areas. The highest concentrations of trichloroethylene (TCE) in groundwater are located under the Nestle property. Also, the isoconcentration contour map shows that the contours for the B-aquifer and the A-aquifer are approximately the same shape and size, and groundwater quality data in these zones are similar under the property. Hence,vertical migration from the B-aquifer to the A-aquifer both under and near the Nestle property has probably already occurred in the past to a significant degree. This fact is supported by the likely interconnectivity of these zones under the site, as described above. However, it is also noted that there have been no detections of TCE in M-5B since 1993, whereas M-5A has relatively constant, low-level detections of TCE. Although it is likely that vertical migration from the B-aquifer to the A-aquifer has occurred both under and near the Nestle property, the likelihood of this occurring at 233 Parallel Avenue is very low. The attached Table 2 indicates that the B/A vertical gradient is uniformly negative over time in B/A well pairs near 233 Parallel Avenue. That is, at points of interconnection, flow would tend to occur from the B-aquifer to the A-aquifer. However, at the well pair closest to 233 Parallel Avenue, M-05A and M-05B, this gradient is extremely low. This implies that if the B- and A-aquifers were interconnected at 233 Parallel Avenue, flow from the B-aquifer to the A-aquifer would be very low, if it would even occur. Based on these facts, even if the stratigraphy at 233 Parallel Avenue were similar to that at the M-5C1/C2 well pair, it is likely that the B-aquifer does not contain TCE at the 233 Parallel Avenue location, whereas it is likely that the A-aquifer already contains TCE at this location. If