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EXECUTIVE SUMMARY <br /> The objectives of this investigation were to further define the extent of impacted soil and to <br /> determine if groundwater had been impacted beneath the site To achieve these objectives, soil <br /> and groundwater-grab samples were collected for laboratory analysis from three soil borings <br /> Soils observed in the three soil borings consisted mostly of clay and silt sequences to the total <br /> drilling depth of 35 feet below ground surface (bgs) This sequence appears to be massive and <br /> laterally continuous across the site During drilling, groundwater was first encountered at depths <br /> ranging from 23 5 to 26 0 feet bgs Groundwater does not appear to be confined and recharge <br /> was found to be moderately strong <br /> Based on the results of the laboratory analyses, soil and groundwater beneath the site have <br /> been impacted by gasoline and kerosene hydrocarbons In soil, the highest concentrations of <br /> petroleum hydrocarbons were detected in the samples collected from G-3, near the south end of <br /> the former 1,000-gallon gasoline UST (UST#2) In groundwater, all three samples contained <br /> detectable concentrations of TPH-as-gasoline, TPH-as-kerosene, and BTEX compounds <br /> ' MTBE and the other oxygenate compounds were not detected in any of the soil or groundwater <br /> samples analyzed <br /> Based on the presence of petroleum hydrocarbons within the unsaturated (vadose), capillary <br /> fringe and saturated soil intervals at G-3, the primary source of the impacts appears to be the <br /> former UST#2 The bulk of the hydrocarbon mass is concentrated in subsurface soil beneath <br /> the south end of former UST #2, and to the east near the former dispenser island <br /> Vertically, the extent of impacted soil is not defined at the total drilling depth of 35 feet bgs <br /> Laterally, the extent of impacted vadose zone soil is defined to the south by G-2 and to the east <br /> ' by G-1 The lateral extent of impacted capillary fringe and saturated zone soil is only defined to <br /> the south by G-2 The extent of impacted groundwater at the groundwater table is not defined <br /> Concentrations of petroleum hydrocarbons in groundwater appear to decline to the south <br /> ' Based on the distribution of petroleum hydrocarbons in soil and groundwater, it appears that <br /> gasoline from the former UST#2, migrated through the vadose zone soil to the groundwater <br /> table and then migrated to the east Based on the soil sample analytical results from G-1 near <br /> ' the former dispenser island and from G-2 at the south end of the former 8,000-gallon gasoline <br /> UST (UST#1), impacts at these locations appear to be limited to shallow soil and do not extend <br /> through the vadose zone to the groundwater table <br /> Based on the results of this investigation, Ramage Environmental recommends that a workplan <br /> be prepared, which outlines additional environmental corrective actions to be completed at the <br /> ' site Prior to proceeding with the additional corrective actions, PHSIEHD had requested in their <br /> letter dated May 16, 2000, that the interested parties meet to discuss the site information and to <br /> prioritize the work relative to five other county sites <br />}, 3 <br /> 1 <br />