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k4 KLEINFELDER 4 FIELD ACTIVITIES The following tasks detail the proposed activities. 4.1 PERMITTING AND PREFIELD ACTIVITIES The San Joaquin County Department of Environmental Health Department (EHD) requires completion of a well permit, and payment of fees prior to abandoning and installing monitoring wells. Kleinfelder will prepare drilling and well destruction permit applications for submittal to EHD along with the required fees. The permits must be approved prior to drilling activities and sampling. EHD usually requires up to approximately two weeks to issue the permits. The drilling subcontractor will contact Underground Service Alert 48 hours prior to conducting fieldwork to notify local utilities of our proposed subsurface assessment. 4.2 MONITORING WELL ABANDONMENT AND RE-INSTALLATION Monitoring well MW-4 will be abandoned in accordance with the EHD guidelines. The well will be over-drilled in an attempt to remove the well casing and construction material from the ground. A pilot bit will be used to direct the auger into the original borehole. The borehole will be grouted to the surface with a neat cement mixture. The grout will be installed via tremmie pipe to fill the borehole from the bottom-up. The grout will be allowed to flow to the ground surface and form a mushroom cap on the ground. One (1) replacement groundwater monitoring well (MW-4r) will be installed at the proposed location shown on Plate 2. The well will be installed to assess first encountered groundwater quality, groundwater flow direction and gradient during the time of sampling. The proposed location is based on estimated groundwater flow towards the northwest and the current location of the PSTF and proposed storm water pond. The well (MW-4r) is proposed to be installed in a downgradient location of leachfield zones 1 through 4 near the northwest corner of the site. The well borings will be drilled with a truck mounted drill rig equipped with 8-inch hollow stem augers. During advancement of the soil boring, soil samples will be collected at five-foot intervals for lithologic classification. Lithologic classification of the new boring for MW-4r will be based on the Unified Soil Classification System (USCS). All downhole equipment used in the drilling and installation procedures will be cleaned and/or decontaminated as described in Appendix A. The well borings will be advanced to approximately 65 feet bgs. Based upon available information, we anticipate groundwater in the vicinity of the project site to be present at a depth of approximately 50 to 55 feet bgs,with a groundwater flow direction to the northeast. 34091.E01/ST05R040/JZ:ly Page 4 of 9 U 2005,Kleinfelder,Inc. January 13,2005