SITE INFORMATION AND CORRESPONDENCE

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Lerner Texaco 521 North Cherokee Lane, Lodi Site Code: 1324 19 April 1997 Page 3 ground surface (bgs) while the northern end samples may be as deep as 20' feet bgs. Monitor Wells: Two on-site and five off-site monitor wells are proposed to verify the contaminant limits established with the CPT survey and better define the groundwater plume in the southwest quadrant (Plate 3). Soil samples will be collected to confirm lithology at 10-foot intervals. A soil sample from within the capillary fringe of each well will be collected for laboratory analysis. Vapor Wells: Three 4-inch diameter vapor wells are initially proposed (Plate 3). The wells will be roughly triangulated to allow an evaluation of potential spacial heterogeneities. Each vapor well boring will be continuously logged to provide detailed lithologic information for remedial design and correlation to the CPT data. It is anticipated that at least VE-1 and VE-2 will be screened from approximately 15 feet bgs to approximately 40 feet bgs. Because VE-3 is proposed in a location where the soil column is not thought to be significantly impacted, VE-3 may be screened near the groundwater's capillary fringe. Final well design will be dependant on field evidence collected during drilling. It is anticipated that four soil samples from each VE boring will be submitted for laboratory analysis. Soil samples collected for analysis will need to be collected from the continuous core barrel and transferred into brass tubes. Analytical: Soil samples submitted for laboratory analysis will be analyzed for total purgeable hydrocarbons as gasoline (TPGg), benzene, toluene, ethylbenzene, and xylenes (BTEX); and methyl tertiary butyl ether (MtBE). MtBE will be included in the Method 8020 analysis. Because of the age of the release and the transport characteristics of MtBE, I do not anticipate positive results for MtBE in soil. Therefore, Method 8260 confirmation is only proposed for capillary fringe samples. Groundwater samples will be analyzed for TPHg, BTEX, MtBE, and dissolved oxygen. If MtBE is reported, Method 8260 will be used the subsequent quarter to verify each positive result. If not reported in any of the wells, Method 8260 will be used to verify the results from two of the wells. Dissolved oxygen and groundwater elevation data will be collected on-site. Air samples will be submitted for analysis of volatile organic vapors by Method TO-14.