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07 May 2002 AGE-NC Project No. 98-0466 Page 3 of 16 associated with the former steam cleaning operation appears to be limite I to shallow soil(less than 5 feet bsg). 3.1.2. Western Drainage Ditch AGE collected a total of six soil samples from the western ditch area d ' g the site assessment of June 2000. TRPH was detected in all samples,but was particularly elevated in sample DS 1-2,which also had elevated concentrations of chromium, lead and zinc. The chromium concentration (663 mg/kg) exceeds the Preliminary Remediation Goal(PRG) for indus trial soil of 450 milligrams per kilogram(mg/kg). The lead concentration(357 mg/kg) exceeds the California modified PRG of 130 mg/kg, but does not exceed the federal EPA PRGs for either re idential or industrial soil. Although zinc concentrations are elevated in DS 1-2 (1,730 mg/kg), the level does not exceed any PRG for the metal. A deeper sample could not be retrieved from hand-iuger boring DS 1, but the concentrations of each analyte decrease northward, where the concentrations: also decrease with depth. Also, deeper soil samples from probe boring DP 1, located nearb , did not contain elevated metals or TRPH concentrations. Analysis of two samples collected in the ditch area for pentachlorophe of and tetrachlorophenol showed no detectable concentrations. Contaminants detected in DS 1-2 w,-re TRPH,chromium,lead and zinc. TRPH in DS 1-2 was characterized as motor oil. TRPH and led concentrations dropped significantly from 2 feet bsg to 5 feet bsg in DS-2. Chromium and zinc were at background concentrations in DS2-5. During the November 2001 site investigation, AGE advanced two boric s (PB5 adn PB6) near the western ditch area to collect soil and ground water samples. TPH-d and TPH-mo were detected in two soil samples collected from boring PBS at concentrations as high as 3.3 mg/kg and 33 mg/kg, respectively. Formaldehyde was detected in the 5-foot sample collected from PB5 and the 10-foot sample collected from P136 at concentrations of 4.3 mg/kg and 6.8 m /kg, respectively. TPH-d, TPH-mo and formaldehyde were not detected in the grab ground water s les collected from each boring. Dissolved chromium was detected in the ground water samples collected from boring P135 and P136 at concentrations of 0.038 mg/l and 0.073 mg/l,respectively. The concentration detected in the P136 water sample was slightly above the DHS Maximum Contaminant Level(WCL) of 0.05 mg/l. Metals concentrations detected in the soil samples collected from PB5 and PB6 are at or near background concentrations. Elevated chromium in soil had been previously detected ' soil sample DSI-2 in the south end of the drainage ditch; however other soil samples in the ditch and adjacent to the ditch have detected only background concentrations, indicating one release point of limited extent. The DS1-2 sample also contained elevated concentrations of leand and zinc, neither of which were Advanced GeoEnvironmcnta4 Inc.