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i Plate 2. The summary data table from the described investigation is attached for convenience. The test data indicate that none of the soil samples contained measurable petroleum hydrocarbons with the exception of Sample B-2-3 which revealed a trace of oil at a concentration of 12 parts-per-million(ppm). Metals were detected in the soil samples at very low concentrations, below levels of concern and at levels commonly attributed to natural occurrence. Neither polychlorinated biphenyls (PCBs) nor polynuclear aromatics(PNAs)were detected in the analyzed samples. Groundwater was generally encountered at a depth of approximately 15 feet during the 1999 work. Groundwater testing revealed gasoline in two samples,diesel in three samples,and chlorinated solvents in four samples. No BTEX,MTBE,or metals were detected in any of the water samples. Neither PCBs nor PNA were detected in tested samples. The compounds detected at each boring location are shown on Plate 1 with letters in parentheses next to each boring:(G)for gasoline;(D)for diesel;and(Sol.)for solvent. Detected concentrations are indicated on the attached Table 1. Gasoline concentrations ranged from 200-850 parts-per-billion(ppb). Diesel levels varied from 62-160 ppb. Various chlorinated solvent concentrations ranged from 0.54-1500 ppb. The highest levels of solvents were detected in samples from Borings B-3 and B-5. This finding is somewhat curious considering that B-3 is located near the former waste oil tank area, and B-5 is situated near the former diesel tank area. Comparison of the detected concentrations to published regulatory levels indicate that only the solvents cis-1,2- dichloroethene and trans-1,2-dichloroethene exceed State and EPA action levels . Our proposed investigation to further assess the horizontal and vertical limits of the mentioned contaminants is detailed below. SCOPE OF WORK GENERAL The investigation will generally include the drilling of four monitor well borings. Three of the monitor wells will be constructed to a depth of approximately 25 feet and will be oriented in a triangular configuration as shown on Plate 2. The fourth well will be near the former B-5 and will be drilled to approximately 50 feet for evaluation of vertical extent. Following the field work and chemical testing of the soil and groundwater samples,a summary report will be prepared in general conformance with Appendix A of the State's Tri-Regional Board Staff Recommendations for underground tank site investigations. A list of specific tasks is presented below. SPECIFIC TASKS • Develop a site specific Health and Safety Plan • Conduct and underground utility survey. • Obtain SJCEMD Well permits. • Perform site investigation under the direct supervision of a California Registered Geologist or Civil Engineer. • Drill four borings into groundwater(3 to 25', and 1 to 50') and placed drill soils in drums. Label and seal drums for on-site storage pending disposal considerations. Ramco n H:\WPDATA\bIIKE\MikeTemp2003U.Anderson\WorkPlan Page 2