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Thirtv soil samples were collected from 10 borings along the north boundary drainage ditch Laboratory analysis detected 20 mg/kg of oil-range hydrocarbons in one neat-surface sample (Boring DD6 at 0 5 foot bgs) Laboratoiy analysis did not detect concentrations of extractable hydrocarbons in any of the other 29 samples Metals concentrations detected in the samples were all below applicable regulatory guidelines (Table 3) No evidence was found to confirm the presence of petroleum hydrocarbons, lead, and zinc detected in previous surface samples The likelihood of extensive lateral or vertical unpacts from the previously detected contamination is considered very low No further investigation is reconunended for the north boundary drainage ditch The bluish white crystalline poAder identified beneath the pa'Yennent uptvelhng areas was determined to contain high copper concentrations and was tentatively identified as copper sulfate The powder reportedly has no hazardous properties, but is toxic if ingested The extent of the buried chemical was not determined, but is not expected to extend beyond the up"A'elling areas Versar recorminends removal of an estimated 100 cubic yards of soil for disposal at a Class I landfill 43 OMS Areas of concern at the OMS comprise the former -vehicle fueling station in the packing lot between the OMS and CSMS, and the vehicle wash tack south of the OMS building Elevated concentrations of petroleum hydrocarbons were detected at depths of 10 to 25 feet bgs in March 2002 Three soil borings (B30 tluough B32) were advanced adjacent to the former location of a 10 000- gallon diesel UST and 5,000-gallon gasoline UST associated with the fonner vehicle fueling station southeast of the OMS Previous investigations had determined that petroleum hydrocarbons identified in shallow soils (from 10 feet to 25 feet bgs) may have the potential to impact groundwater The findings of the 2004 investigation identified petroleum hydrocarbons in deepen soils (from 35 to 45 feet bgs) and in groundwater The lateral extent of groundv ater impact was not determined to the north, east or south The lateral extent of groundwater impact Was tentatively defined to the east and northwest by soil bongs B33 and B34 Further investigation is recoini vended to determine the lateral extent of petroleum hydrocarbons in groundwater Two soil borings (B33 and B34) weze advanced adjacent to the vehicle inspection rack located south of the OMS building to further define the extent of petroleum hydrocarbons detected at 10 feet bgs in previous investigations Evidence of extensive impacts from the pieviously detected petroleum hydrocarbon contamination was not encountered Evidence of groundwater impact was not detected No further investigation is recommended for the Vehicle Inspection Rack i 104700 4766 2301085EPT2004 12