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1 • Log soils continuously and collect undisturbed soil samples at 10-foot depth intervals. • Screen soils for petroleum vapors and select one sample from each of the 25' borings for chemical testing - on basis of highest screening indication, or if no indication,submit the 20 foot or capillary fringe sample for testing. Select three samples for testing from the 50' boring (six total soil samples). • Construct monitor wells in each of the borings in conformance with the attached Monitor Well Detail. The 25'borings will be screened in the lower 15 feet. The 50' boring will only be screened in the lower 5 feet to assess lower-level groundwater conditions. The upper 45 feet will consist of blank casing and a grouted annular space. • Following a 48-hour grout cure period, survey the well casings at each location relative to an on-site benchmark,and measure groundwater depth to the nearest 0.01 foot. • Purge the wells of at least three casing volumes of water. Allow the displaced water level to recover to within at least 80% and collect a water sample from each of the wells. • Submit the 6 soil and 4 water samples to a California-certified laboratory. The samples would be tested for gasoline, diesel, BTEX, 5 common oxygenates, and halogenated volatile organic compounds. Test methods would include the Mod EPA 8015 and 8260B methods. Because no PCBs, PNAs,or elevated metals were detected in soil or water samples in 1999,no testing for these constituents is considered necessary. • Prepare a summary report in general conformance with Appendix A of the State's Tri-Regional Board Staff Recommendations for underground tank site investigations. PROCEDURES Field Work The work will be performed in general conformance with the detailed Standard Procedures presented in the Appendix. The borings will be drilled in the approximate locations shown on Plate 2. Each drilling location will be surveyed for utilities and/or other obstructions prior to mobilization of the drill rig. Drilling operations will be performed by a C57-licensed contractor directed by a California registered Geologist or Civil Engineer. All of the site work will be performed by personnel certified for hazardous site operations training in accordance with 29 CFR 1910.120. Each boring will be logged in the field for inclusion in the summary report. Ramco n H:\WPDATA\MIKE\MikeTemp2003V.Anderson\WorkPlan Page 3