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29 January 2002 <br /> ' AGE-NC Project No. 98-0466 <br /> Page 6 of 25 <br /> ' AGE collected soil samples in the SCA2 area in December 2000 to a3sess for hydrocarbons and <br /> selected metals -chromium, lead,nickel, copper and zinc(Figure 3). TR PH was not detected in two <br /> ' shallow soil samples (one foot bsg) located between the former steam cleaning area and the west <br /> ditch. Detected concentrations of chromium, lead and zinc were witkin levels considered to be <br /> background. <br /> ' As part of AGE's investigation of the SCA2 area, one soil boring w advanced adjacent to the <br /> western ditch area identified by D&M as an area of concern. The bo g was advanced to first <br /> encountered ground water to collect soil and grab ground water.same . Two soil samples were <br /> analyzed, one from 10 feet bsg and one from 15 feet bsg, to ass ss the vertical extent of <br /> contamination previously encountered in sample DSI-2 during the rune 2000 assessment, as <br /> ' discussed below. Concentrations of detected TRPH were not above laboratory reporting limits for <br /> either sample. Metals concentrations (chromium, lead and zinc) were consistent with background <br /> levels. The collected ground water sample did not contain detectable concentrations of TRPH, but <br /> ' did contain 0.95 mg/I chromium 0.17 mg/I lead, and 2.07 mg/1 zinc. The ground water sample had <br /> not been filtered and the detected metals are most likely soil components in the sample. Based on <br /> the results of the December 2000 assessment, contamination associated with the former steam <br /> cleaning operation appears to be limited to shallow soil(less than 5 feet g). Analytical results are <br /> summarized in Tables 7 and 8. <br /> ' 2.2.3. Western Drainage Ditch <br /> ' AGE collected a total of six soil samples from the western ditch area during the site assessment of <br /> June 2000. TRPH was detected in all samples,but was particularly elevated in sample DS 1-2,which <br /> ' also had elevated concentrations of chromium, lead and zinc. The chromium concentration <br /> (663 mg/kg) exceeds the Preliminary Remediation Goal (PRG) for indus trial soil of 450 milligrams <br /> per kilogram(mg/kg). The lead concentration(357 mg/kg) exceeds the California modified PRG of <br /> 130 mg/kg, but does not exceed the federal EPA PRGs for either r idential or industrial soil. <br /> ' Although zinc concentrations are elevated in DS 1-2 (1,730 mg/kg), the level does not exceed any <br /> PRG for the metal. A deeper sample could not be retrieved from hand- ger boring DS 1, but the <br /> ' concentrations of each analyte decrease northward, where the concentlations also decrease with <br /> depth. Also, deeper soil samples from probe boring DP 1, located nearby, did not contain elevated <br /> metals or TRPH concentrations. <br /> Analysis of two samples collected in the ditch area for pentachlorophenol and tetrachlorophenol <br /> showed no detectable concentrations. Contaminants detected in DS 1-2 w re TRPH,chromium,lead <br /> ' and zinc. TRPH in DS 1-2 was characterized as motor oil. TRPH and lea d concentrations dropped <br /> significantly from 2 feet bsg to 5 feet bsg in DS-2. Chromium and duc were at background <br /> concentrations in DS2-5. Analytical results are summarized in Table 7. <br /> 1 <br /> Advanced GeaFnviry mental Inc. <br />