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AOC Work Plans background levels of 235 mg/kg and 262 mg/kg,respectively in one camp (HA3 [collected at a depth of 6-inches bgs]; Plate 4.4a). The elevated lead and zinc concentrations were interpreted by AGE as pos ibly being due to runoff from the steam cleaning area and appeared to have a limited lateral extent. hi December 2001,AGE installed an additional boring(PB-3)in the south steam cleaning area and collected a soil(at a depth of 5.0 feet bgs)and grab groundwater sample in the boring. The samples were analyzed for TPHg,TPHd,TPHmo,chromium,lead, and a o. TPH compounds were not detected in the soil sample and detected metals were within back ound ranges (AGE, 1001). With the exception of TPHd,detected at a concentration of 0.064 r ig/L,all analytes were below laboratory reporting limits for the groundwater sample. Steam Cleaning Area—North(SCA2) hi December 2000, AGE collected two near surface soil samples (NSB-1 d NSB-2)from a depth of 1.0 feet bgs in the SCA2 (Plate 4.4b)area to assess the presence of hydi ocarbons and selected metals; chromium,lead,nickel, copper and zinc. Total recoverable petrol um hydrocarbons (TRPH)were not detected above laboratory reporting limits in either sam le collected between the former steam cleaning area and the ditch. Detected concentrations of chro mium, lead and zinc in these samples were within background levels(AGE, 1001). Western Ditch Area In June 2000,AGE collected a total of six soil samples at depths between .0 and 5.0 feet bgs from borings DS-1 through DS-3 located in the Western Ditch Area(Plate 4.4b . TRPH,TPHmo,and lead all were detected above the cleanup levels in one sample(DS 1 at 2.0 eet bgs)at concentrations of 2,479,2,200, 357 mg/kg respectively. Lead,exceeded flie California modified PRG of 150 mg/kg. Zinc was also elevated in this sample(1,730 mg/kg), ut well below the Draft KB61125 workplan-Esc MACTEC Engineering and Consulting, Inc. 39 September 28,2005