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k4 KLEINFELDER 7. Six discrete soil samples were collected in a former organophosphate pesticide chemical storage area. No organophosphate pesticides were detected in any of the six shallow soil samples. Based on this information, Kleinfelder does not recommend farther assessment in this area for organophosphate pesticides. 8. Kleinfelder advanced a single soil boring to an approximate depth of 30 feet bgs in the former northern UST areas at the subject site. No requested petroleum constituents were detected in the soil boring (DB-1). Additionally discolored soil or petroleum-like odors were not noted from cuttings or soil sampling at this location. Based on the field observations and analytical results it q does not appear petroleum impacted soils remain in this UST excavation at the explored depths 6 and location of DB-1. 9. Two borings, DB-2 and DB-3 were advanced in the former southern UST area to approximate s total depths of 50 and 30 feet bgs,respectively. Two soil samples collected in the western portion of this excavation area (DB-3) were reported as non-detect for the requested petroleum constituents. Three soil samples were collected in deep boring DB-2 advanced in the eastern portion of southern excavation at depths of 30, 40 and 50 feet bgs. TPH-D, TPH-G, toluene, ethylbenzene and total xylenes were detected at elevated levels in the 30 foot soil sample, although the 40 foot sample had markedly lower to non detect concentrations of these same analytes. The 50 foot sample was none detected for all requested petroleum constituents. Based on this data, it appears petroleum impacted soil remains in the eastern portion of the southern excavation at depths from approximately 25 to 45 feet with the highest concentrations at depths of approximately 30 feet bgs. 10. Soil samples were collected every five feet during advancement of the four well borings (MW-1 through MW-4). No soil discoloration or unusual odors were noted either from soil cuttings or the soil samples collected. A single soil sample was collected and submitted for analyses from each well boring at depths estimated just above first encountered groundwater ranging from 46 to 56 feet bgs. None of the requested petroleum constituents were detected at or above laboratory reporting limits. Based on these field observations and soil sampling results it does not appear that soils have been impacted by petroleum constituents at these locations. However, it should be noted that soils may become impacted due to the petroleum constituents detected in groundwater at the MW-4 location near first encountered groundwater including zones in which groundwater I may fluctuate seasonally. 11. One four point composite sample was analyzed from an approximately 75 yard stockpile located at the subject site. Based on the analytical results it appears diesel and motor oil impacted soil remain in this stockpile RECOMMENDATIONS 1. Kleinfelder recommends shallow excavation of petroleum impacted soil in the washdown area followed by confirmation soil sampling. The approximate 75 cubic yard soil stockpile located at the site should be disposed of according to local and federal regulations. Kleinfelder recommends removal of the excavated washdown area soil and the existing stockpile in a single disposal event. 2. Previous remedial activities (excavation of petroleum impacted soil) have occurred at the subject site in the former UST area and a"No Further Action" letter was obtained from the county. Field observations and soil sampling results in the vicinity of the UST shows that petroleum impacted soil remains at approximately depth of 25 to 45 feet in the eastern portion of the southern excavation. However, soil sampling results show a marked decrease in petroleum constituents at i 1 42747703 J STO4R882 Page 4 of 9 Copyright 2004,Kleinfelder,Inc. July 2,2004