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Frank C. Alegre Trucking Company,Inc. 4203-F3 Former Trucking Facility March 25, 1997 WORK PLAN FOR MONITORING WELL INSTALLATION Page 2 PROPOSED MONITORING WELL INSTALLATION The proposed location of the additional monitoring well is indicated on Figure 1. The well boring will be advanced using a truck mounted drill rig equipped with 8V4-inch-diameter hollow-stem augers. Exploratory drilling and soil sampling protocol details are provided in Appendix B. The monitoring well will consist of 2-inch-diameter PVC casing with flush joints, installed down through the hollow stem auger. The well will be constructed with 20 feet of screened casing (0.020-inch slot width) and an appropriate length of solid PVC well casing (2-inch-diameter Schedule 40 PVC). The total depth of the monitoring wells is estimated at 50 feet. A #2/16 sand filter pack will be placed from the base of the well to approximately two feet above the top of the screened interval. A±12-inch-thick bentonite seal will be placed at the top of the filter pack. The remaining annular space will be backfilled with a cement-bentonite grout seal. The well will be completed with a flush mounted 8-inch manhole. The top of the well casing will be secured with a locking waterproof cap. Soil and Ground-Water Sampling Soil samples will be recovered on five foot intervals from the base of the former UST excavation, 30 feet below the ground surface, to the base of the well. The overlying material consists of clean imported fill; therefore, the soil from the surface to 30 feet will not be sampled. Soil samples will be sealed with Teflon, plastic end caps, and tape. ENGEO anticipates three to four soil samples will be retained for laboratory analysis. The samples will be preserved in a cooled ice chest for transportation under documented chain-of-custody to American Environmental Network, in Pleasant Hill, California. The drill cuttings will be stockpiled, pending a review of the field PID screenings. A mitigation plan for the soil cuttings and rinseate will be developed based on the findings of the laboratory testing After the cement-bentonite grout has set for 72 hours, the well will be developed using a surge block, bailer, or submersible pump, to produce relatively non-turbid ground water. We anticipate that ten to twenty well volumes of water will be removed from the well during the development process. The purge/rinseate water will be stored on the site in Department of Transportation approved drums until the results of the laboratory testing are available. At that time a remediation/disposal plan for the purged water could be developed. ' Drilling services provided by Western Strata Exploration,Inc.(C57#552198)