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1 ' 11 September 2001 AGE-NC Project No. 98-0466 Page 6 of 24 ' hydrocarbons and selected metals. Four shallow soil samples (0.5 to 2 feet bsg) contained TRPH concentrations ranging from 40 mg/kg to 360 mg/kg, which appear to be slightly elevated. Concentrations of chromium in the four samples were within background levels. One sample, ' HA3-6", contained concentrations of lead and zinc that exceed California background levels at concentrations of 235 mg/kg and 262 mg/kg,respectively. Lead and zinc in the other three samples were within background levels common for California soils (Kearney Foundation, 1996). Figure 3 shows the AGE sampling localities in the area. Table 1 shows the analytical data obtained by AGE from the soil samples. The TRPH concentrations were characterized by the laboratory as being in the motor oil hydrocarbon range; the elevated lead and zinc concentrations may be due to runoff ' from the steam cleaning area and appear to have a limited areal extent. A report of procedures and findings for the December 2000 investigation is in preparation. One boring(PB4)will be advanced in the area to collect soil and ground water samples to assess for total petroleum hydrocarbons,lead ' and zinc. 3.2.2. North Steam Cleaning Area- SCA2 According to Mr. Glen Gallup of AM&M, following cessation of op ations at SCAT, the steam ' cleaning operation was temporarily continued in the SCA2 area. This area was located along the drain line and three-sump system that conveyed waste water from the SCAT area to the western ' ditch, which again may have been utilized to dispose of waste water generated by the operation in the SCA2 area;additionally,runoff from the operation may have migrated toward the western ditch. ' AGE collected soil samples in the SCA2 area in December 2000 to assess for hydrocarbons and selected metals-chromium,lead,nickel,copper and zinc(Figure 3).T was not detected in two shallow soil samples (one foot bsg) located between the former steam cleaning area and the west ditch. Detected concentrations of chromium, lead and zinc were within levels considered to be ' background. ' As part of AGE's investigation of the SCA2 area, one soil boring wa� advanced adjacent to the western ditch area identified by D&M as an area of concern. The boring was advanced to first encountered ground water to collect soil and grab ground water samples. Two soil samples were ' analyzed, one from 10 feet bsg and one from 15 feet bsg, to assess the vertical extent of contamination previously encountered in sample DS1-2 during the June 2000 assessment, as discussed below. Concentrations of detected TRPH were not above laboratory reporting limits for ' either sample. Metals concentrations (chromium, lead and zinc) were consistent with background levels. The collected ground water sample did not contain detectable c 'ncentrations of TRPH,but did contain 0.95 mg/1 chromium, 0.17 mg/l lead, and 2.07 mg/l zinc. T e ground water sample had ' not been filtered and the detected metals are most likely soil compone s in the sample. Based on the results of the December 2000 assessment, contamination associated with the former steam ' cleaning operation appears to be limited to shallow soil(less than 5 feet bsg). Analytical results are Advanced GeoEnvironmental,Inc. 1