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Cleanliness: All sample equipment (i.e., split spoon sampler, brass tubes and teflon bailer, auger, bit and drilling rods) were thoroughly steamed cleaned before being used in the first hole and between uses. Monitoring Well: Three monitoring wells were installed. Each well was constructed of 2 inch PVC pipe, factory slotted (.02 inch) from 15 to 10 feet with blank casing from 10 feet to the surface. The well was packed with 43 sand from 15 to 8 feet and has an annular seal composed of bentonite grout above the packing. Each monitoring,well was secured with a locking cap and water tight well box. A schematic of monitoring well construction is shown in f=igure 3. Water Depth: Depth to lop of ground water was measured with a Solinst water level .; meter. Solinst snakes a very high quality water meter with stretch resistant stainless steel cabled tape. Length is marked in feet and tens of feet(marks every i 1/20 feet). Chain of Custody: Soil and groundwater samples were collected by Dave Meade, Dr. Kablanow delivered the samples to California Water Labs and turned them over to Linda French. Ms. French is the sample status personnel for the lab. Chain of ' tA custody forms are kept on file at Geological Technics. Samples that were not analyzed are kept refrigerated at Geological Technics. Laboratory Analysis: Five soil samples were analyzed in the lab for gasoline, benzene, toluene,and xylene. Head space analysis was done on these five using both a gas s R- chromatograph and flame ionization detector(GC/FiD). One soil sample was also analyzed for total lead. Fifteen ground water samples were analyzed for gasoline (using head space, method 506) and purgeable aromatic hydrocarbons (using EPA I method 602). This data is summarized in Table 1 & 2 and the individual sample data w sheets are given in Appendix S. f Detection.Limits of Analysis: For purgeable aromatics (method 602), the detection litnit Is 0.5 parts per billion (ppm; recorded as ug/L). For gasoline, the detection ' limit is 1 ppm (mg/kg) in both soil and water. Detection limit for total lead is 0.01 ppm (mg/L) Data Reduction: Geological observations (i.e., boring logs, sediment description and distribution) were carefully interpreted and stratigraphic cross sections were draw. These cross sections and the contour maps are the basis for interpreting the ,�j distribution of soil contamination. Soil contamination data was correlated to the discoloration of the sediments caused by the microbial degradation of the gasoline, which Is shown on the cross sections. Soil and ground water contamination are contoured in plan view. 5