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k.- Ct�ylOrt f..\l';Kf j.��tlE\LLi [.MNSULTAI;TS MW-3 was installed at the southwest corner of the property adjacent to and downgradient of the former location of the UST (Figure 2). MW-1 was installed - at the northwest corner of the property to monitor a diesel UST located west of the subject site at Leprino Cheese Company. MW-2 was installed at the northeast corner of the property to complete the triangle so that groundwater flow direction and gradient could be calculated. Litholo4ical logs recording the soil types underlying the site were maintained by Clayton s geologist. Copies of these logs are presented in Appendix D. Soil samples were taken at approximately 5 feet and 10 feet below the ground surface (bgs) in all three boreholes. Groundwater was first encountered at 13 feet bgs in MW-1, 8 feet bgs in MW-2, and 14 feet bgs in MW-3, although the water later rose a few feet in MW-1 and MW-3. After completing the boreholes, the auger was removed and 4-inch diameter wells installed to the following depths: �� DEI; TO WAT.�R DEP'1'�O� .ELS s MW-1 8.39 25 8.28 20 MW-3 10.77 25 Figures 3, 4, and 5 show schematic well construction diagrams of the three installed monitoring wells. Clayton marked the wells with orange stakes so that they can be easily found during future construction on the site. Waste drill cuttings,as well as purge water from well development and sampling, were placed into Department of Transportation (DOT)-approved drums for proper disposal at a later date. These drums were labeled with the name of the site, address,well number, and the drum contents and left at the site. 3.2 WELL DEVELOPMENT AND WATER SAMPLING Clayton surged and pumped the monitoring wells with a 4-inch submersible pump on April 4, 1990. This was done to stabilize the filter material and remove turbid water caused by drilling operations. We removed approximately 75 gallons (8 well volumes) from MW-1, 50 gallons (6.5 well-volumes)from MW-2; and 70 gallons (7 F -- well volumes) from MW-3. MW-2 and MW-3 recovered slowly and were purged dry several times. Tap water was add.--d to these wells periodically to aid in development. MW-1 recovered quickly and did not require any additional water. We sampled groundwater from the monitoring wells on April 6, 1990, in accordance with the protocols in Appendix B. MW-I and MW-2.were purged of 5 well volumes each: MW-3 was purged dry twice and allowed to recover at least 80% before sampling. The field data sheets of the purging/sampling are included - , as Appendix E. -2-