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r R t Y , r 05 May 1997 AGE-NC Project No 95-0139 ' Page 2 of 9 , ' 23 EXCAVATION OF HYDROCARBON-IMPACTED SOIL t 2 3 1 INITIAL EXCAVATION In January f990, additional hydrocarbon-impacted soil was removed to a depth of 14 feet below surface grade (bsg) from the former UST area Excavation was performed under the direction of Geological Technics(GT) However,it is our understanding that no soil samples were collected from the excavation - ' In a 08 May 1993 letter, the PHS-EHD states "At some time prior to 08 May 1990 the excavation was filled to 7 feet bsg The material used to fill the excavation to that level has never been clarified At some time after May 1991 the stock piled soil at the site was placed back into the excavation ' 1 However, an October 1992 Invitation For Bids prepared for the property owner indicated that the ' stockpiled soil was spread for aeration until August 1990 The soil was then placed in the excavation and clean fill material was imported to fill the excavation to surface grade The backfilling was done without nobfication'to the PHS-EHD, and therefore, no official documentation was available On 04 January 1990, eight composite soil stockpile samples were collected by GT Ina 29 November 1990 letter,the PHS-EHD stated that they had not received a chain-of-custody form for ' the samples or a site map showing sample locations However, the laboratory report was available Three more composite samples were collected at the site on 11 September 1990 Again, the laboratory report was available, even though the chain-of-custody and sample location map were not included for these samples The samples appear to have been collected from the stockpiled soil prior' r ,to backfilling of the excavation Analytical results are summarized on Table 2` 2 3 2 EXCAVATION DEWATERING AND WATER DISPOSITION ' During the January 1990 excavation procedures, the tank pit was dewatered and the water placed in an 8,000-gallon above ground tank and stored on-site At some'time after the excavation,was ' backfilled,the water stored on-site was°released to the area of the former excavation location Water samples were collected at the site on 05 January, 09 January and 15 August 1990 The samples were labeled as GTI 8 Water 1, GTI 8 Sump and Tank, respectively Again, the laboratory report was- ' ' available, bait the chain-of-custody acid description of sampling was not- The sample collected on 15 August 1990 appears to have been collected from,the above ground storage tank prior to discharge of the water to the excavation location No report describing the excavation, stockpile ' sampling, backfilling procedures or sampling and disposition of the water removed from the • excavation was found by AGE Analytical results of water samples are summarized on Table 7 s