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r Samples TP-1 to TP-6 were collected using the backhoe bucket; sample TP-7 was collected directly from the wall of the excavation I using a metric soil sampler with extensions. All samples were collected at depths between 11 and 15 feet. The sample depths are indicated in Table 3 . Soil samples were collected in clean, 2 by 3-inch brass tubes. The ends of the tubes were covered with aluminum sheets, capped and sealed with tape. The samples were stored on ice and transported to Alpha Analytical Laboratories in Ukiah. The samples were analyzed for total petroleum hydrocarbons (TPH as gasoline and diesel) and BTE&X in accordance with EPA methods 8015m and 8020, respectively. 3. 3 Monitoring Well Installation On August 19 , 1993 , monitoring well MW-4 was installed down- gradient from MW-1 on the neighboring property, north of the site (Figure 2 ) . 3 .3 . 1 Drilling The boring was advanced to a depth of 20 feet using a truck- mounted 8-inch hollow-stem auger rig. The Acker drill rig and two- man crew were supplied by West Hazmat Drilling Corporation. 3 .3.2 Soil Sampling Discrete soil samples were collected at five-foot intervals ahead of the drill bit using a split-tube sampler loaded with three pre- cleaned 2 by 6--inch brass tubes. The sample collected at a depth of 5 feet was driven into the soil with a 140-1b hammer, and the number of blows required to advance the sampler in six-inch increments was recorded on the boring log. Because of a broken rope, the hammer could not be used to advance the sampler for the remaining samples. Instead, the drill rig was used to press the sampler into the soil . All samples were advanced easily, indicating I soft soil at each sample location. To avoid cross contamination, the sampling equipment was washed in a tri-sodium phosphate (TSP) solution and rinsed twice with water prior to each sampling run. IFor each sample, both ends of the lead tube were covered with aluminum foil, capped and sealed with tape. The samples were labeled, logged on a chain of custody form, and stored on ice Pending transmission to Alpha Analytical Laboratories in Ukiah. Three soil samples were analyzed for TPH as gasoline and diesel and BTE&X in accordance with EPA methods 8015m and 8020, respectively. 3 . 3.3 Logging Auger returns and soil from the middle sample tube were monitored for the presence of organic vapors using a photo-ionization I 7