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June 26, 2003 Trust of Mary Gardella Page 2 This data showed additional sand strata present at depths of about CPT-2 at 52-57 feet, and 114- 119 feet below site grade. Boring CPT-1 showed apparently correlative sand strata at 57-62 feet and another separate sand strata at 113-120 feet. Additional vertical and lateral extent of these strata zones is desired given the appearance of low to moderate concentrations of 1, 2-DCA as well as some apparently anomalous migration of both 1, 2-DCA and petroleum contaminants. Site stratigraphy is suggestive of alluvial channel cut and fill depositional environments and more assessment work are warranted to attempt to gain more understanding of these sand strata bodies location and extent. Wright and PHS EHD agreed that the site characterization should proceed to assist in both strata contaminant zones location and targeting additional monitoring wells location and slotted intervals. The characterization would be needed also for any cleanup plan. Four additional wells were required in the April 25, 2003 workplan. Additional wells may be warranted to monitor 1, 2-DCA and petroleum migration at these different depths once the additional CPT borings are drilled and the stratigraphic and chemical groundwater data is reviewed. Proposed Addendum Additional Drilling and Site Characterization Work Tasks Wright proposes to include the following work tasks as an addendum to the April 25, 2003 workplan. • Drill and log three additional Cone Penetrometer (CPT) borings at the locations shown on Figure 1. These borings will be used to sample the water bearing zones to further delineate both site stratigraphy and contaminant presence. Groundwater samples from 52- 57 feet, and 114-119 feet and other zones (if log data suggests) will be analyzed for the same contaminants as initially proposed (that is Total Petroleum Hydrocarbons as Gasoline (TPHG), Benzene (B), Toluene (T), Ethylbenzene (E), Xylene (X), Methyl-tert- butyl-ether (MTBE), and fuel oxygenates tert-Amyl-Methyl-Ether (TAME), Ethyl-tert- Butyl-Ether (ETBE), Di-Isopropyl Ether (RIPE) and tert-Butyl Alcohol (TBA) and 1, 2- Dichlorethane (1, 2-DCA). • Review of on-site and off-site stratigraphy using all previous boring log data and the three new borings. Geologic cross section(s) will be prepared to interpret the overall site stratigraphy and sand strata of interest. The review will place emphasis upon the lateral and vertical variations of these strata and their apparent extent assuming that these strata are the potential pathways of highest hydraulic conductivity. The sand strata at 52-57 feet, and 114-119 feet below site grade will be evaluated regarding lateral extent and interpreted channel deposition and lateral and vertical facies changes relation to these strata zones on the site. Page 2 of 6