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27 October 2005 AGE-NC Project No. 96-0235 Page 3 of 11 The"Medial"sampling(during the 5 days of ozonation)was accomplished via a sipper tube that was immersed below the upper level of the aqueous phase and was accessed by disconnecting the reaction vessel outlet tubing and withdrawing 20-30 ml of sample via a luer tipped syringe. Ozone flow was stopped during sampling. Generally 20ml of water was removed each time resulting in a 60/500 or 12%decrease in fluid volume.This factor has not been taken into account in the analytical data. At the end of Day 5,the ozone flow was permanently stopped.A Final Water and Final soil samples were withdrawn. The Final soil was found contain 1 /0.8 = 125%more water than the Initial soil. This correction factor was significant_ for TTLC trace metals and this correction factor was applied to TTLC Final soil metals values.A significant volume of water was removed for the Final water tests and approximately 200m1 of de-ionized water was added to the sample for decay studies.Ozone and hexachrome were measured for another 8 days. Approximately 20-30m1 sample aliquots were withdrawn between 3 and 5 pm on each day from 12 April to 19 April. A syringe aliquot was withdrawn in the same way as for the medial samples. OBSERVATIONS, INTERPRETATIONS AND CONCLUSIONS General VIEW Overall,pH increased from 7.89 to 8.3,while alkalinity, TDS, EC,& Ca+2 decreased in the aquifer water. These effects are consistent with the pptn of CaCO3 in response to the pH increase. The degassing of COz,gas, is probably the dominant reaction that causes pH to increase. These precipitation reactions as well as those of Fe and Mn oxides will diminish permeability,although the extent and hence significance is not known. Note that the Initial soil pH = 8.94 measured on de- ionized water in equilibrium with the soil is very different from the pH=7.89 of the aquifer water. Water Quglily With regard to other water quality parameters, chloride was conserved, as expected. Sulfate increased moderately from 130 to 160 mg/L,perhaps due to reactions except with sulfate as the end product. Unexpectedly, ORP decreased from 419 to 217 my with ozonation, perhaps because the significantly increased dissolved hydrocarbons now control the redox potential. Hydrocarbons AND VOCs Good agreement is generally found between 8260 and 8020/8021 for MBTEX hydrocarbons except for the initial soil values. The data were double checked and no errors were found, extraction surrogate recoveries agreed with stated dilution factors,so the explanation for this defaults to sample in-homogeneity. Advanced GeoEnvironmental,Inc.