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%mow hydrocarbon odor or soil discoloration was present in the tank pit. However, analytical results from samples collected from native soil beneath the tanks indicated that low levels of petroleum hydrocarbons existed. Soil analytical results from the tank removal are summarized in Table 1. 2.2 Scope of Work The scope of work consisted of drilling soil borings in the center and along the perimeter of the former tank pit. Soil and groundwater samples were collected for subsequent laboratory analysis. Field work was conducted August 30, 1999. 3.0 INVESTIGATIVE PROCEDURES Fisch Environmental (C57- 683685) advanced the borings under the supervision of field geologist Sean Garvey, and project manager Gregory P. Stahl, a California Registered Geologist. Perimeter borings SB 1, SB3 and SB4, located approximately nine feet east, nine feet south and seven feet northwest from the center of former tank pit, respectively, were advanced to a depth of approximately 16 feet below ground surface (bgs) in order to investigate the lateral extent of any residual contamination. Boring SB2, located in the center of the former tank pit, was advanced to approximately 31 feet bgs to explore the vertical extent of contamination at the site(Figure 2). Fisch Environmental utilized a truck mounted Geoprobe 5400 direct push rig to advance the borings and collect soil samples. Soil samples were collected at 5-foot intervals using a 1-inch diameter by 24-inch long core sampler. The sampler was lined with clear acetate sleeves, affording soil identification and subjective evaluation for contamination. A flame ionization detector (FID) was used to monitor the presence of volatile organic compounds in the soil. Samples selected for analysis were sealed, labeled, and immediately placed into an ice chest chilled to approximately 4°C for transport to a state-certified analytical laboratory. Soil samples selected for analysis were based on observations and field screening results. "Grab" groundwater samples were collected from boring SB2. To collect the groundwater samples, a core sampler was driven to the desired depth. The screen was then exposed to the bed within the formation. A 0.17 inch diameter Teflon tube equipped with a stainless steel check valve was then inserted into the rods to the bottom of the sampler. The groundwater samples were retrieved by creating a positive displacement effect in which water is forced upwards through the Teflon tubing, and transferred from the Teflon tubing directly into appropriate glass containers. The containers were then sealed, labeled, and placed into an ice chest chilled to approximately 4°C for transport to a state-certified analytical laboratory. The completed borings were backfilled to the ground surface with neat cement grout. No soil cuttings were generated. All down-hole drilling and sampling equipment was decontaminated by washing with a laboratory grade detergent and rinsing thoroughly with water. Rinseate collected from decontamination procedures was disposed of via evaporation on the asphalt/concrete surface within the confines of the investigation area. Soil and groundwater samples were submitted under chain of custody protocol to Argon Laboratories (FLAP 2359) for analysis. Boring locations are shown on Figure 2. Field notes are included in Attachment A.