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levels of concern and at levels commonly attributed to natural occurrence. Neither polychlorinated <br /> biphenyls (PCBs)nor polynuclear aromatics (PNAs) were detected. <br /> Groundwater was generally encountered at a depth of approximately 15 feet during the 1999 work. <br /> Groundwater testing revealed gasoline in two samples,diesel in three samples,and chlorinated solvents <br /> in four samples. No BTEX,MTBE,or metals were detected in any of the water samples. Neither PCBs <br /> nor PNA were detected in tested samples. The compounds detected at each boring location are shown <br /> on Plate 2 with letters in parentheses next to each boring: (G)for gasoline;(D)for diesel; and(Sol.)for <br /> solvent. Detected concentrations are indicated on the table at the end of the Appendix. Gasoline <br /> concentrations ranged from 200-850 parts-per-billion (ppb). Diesel levels varied from 62-160 ppb. <br /> Various chlorinated solvent concentrations ranged from 0.54-1500 ppb. The highest levels of solvents <br /> were detected in samples from Borings B-3 and B-5. This finding is somewhat curious considering that <br /> B-3 is located near the former waste oil tank area, and B-5 is situated near the former diesel tank area. <br /> Comparison of the detected concentrations to published regulatory levels indicate that only the solvents <br /> cis-1,2-dichloroethene and trans-1,2-dichloroethene exceed State and EPA action levels . Our more <br /> recent investigation to further assess the horizontal and vertical limits of the mentioned contaminants <br /> is detailed below. <br /> RECENTLY COMPLETED SCOPE OF WORK <br /> GENERAL <br /> The investigation has generally included the drilling of four monitor well borings. Three of the <br /> monitor wells have been constructed to a depth of 25 feet and are oriented in a triangular <br /> configuration as shown on Plate 2. The fourth well is located near the former B-5 and has been <br /> drilled to approximately 50 feet for evaluation of vertical impact. A list of the completed tasks is <br /> presented below. <br /> COMPLETED TASKS <br /> Preparation of a site specific Health and Safety Plan <br /> • Underground utility survey. <br /> Obtained SJCEMD Well permits. <br /> • Performed site investigation under the direct supervision of a California <br /> Registered Civil Engineer. <br /> Drilled four borings into groundwater(3 to 25 , and 1 to 50')and placed drill <br /> soils in drums. Labeled and sealed drums for on-site storage pending <br /> disposal considerations. <br /> • Logged soils continuously and collected undisturbed soil samples at <br /> approximate 10-foot depth intervals. <br /> Screened soils for petroleum vapors and selected one sample from each of the <br /> 25' borings for chemical testing - on basis of nearness to the apparent <br /> Ramco n H:\WPDATA\1303-2-Anderson\REPORTS\SumReport.wpd Page 2 <br />