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Ms. Devra Lewis • • Project 812717 April 9, 2001 Page 3 of 4 space between the PVC casing and the borehole wall. Sand will be added to the borehole through the temporary casing to provide a uniform filter pack around the casing and to stabilize the borehole. The sand pack will be placed to a maximum of 2 feet above the screens,followed by a 3- foot seal consisting of bentonite pellets. Cement grout containing 5 percent bentonite will be placed above the bentonite seal to the ground surface. A watertight locking cap will then be installed over the top of the well casing and a well monument or flush-mount traffic-rated vault box installed over the well. The proposed well completion details are shown in Table 1. A detailed discussion of drilling methods and well construction details are presented in Appendix A. Task 2C - Groundwater Monitoring Well Development and Surveying The monitoring wells will be developed by bailing, surging with a surge block, pumping, or a combination of these techniques. Development will continue, to the extent practical, until the development water runs clean and pH and conductivity measurements stabilize (pH varies less than or equal to 0.02 and conductivity varies less than 10 percent). After the wells have been developed and water levels have stabilized the water levels will measured and the volume of water removed from each well will be recorded and included in the investigation report. The newly installed monitoring wells will be included in the ongoing quarterly groundwater monitoring and reporting program and will be sampled during the subsequent sampling event. IT will contract a licensed land surveyor to survey the well location and top of casing with respect to mean sea level. TASK 3 - REPORTING IT will prepare an investigation report following completion of field activities and receipt of analytical results. The report will summarize the field work performed, present drilling and sampling procedures, and include a boring/well location map, revised geologic cross-sections (if warranted), and interpretation and discussion of the subsurface investigation results. PROJECT SCHEDULE IT anticipates the well installation and well development will require approximately 15 to 20 days to complete. IT proposes to schedule a driller upon receiving approval of this workplan. IT will contact the RWQCB and the DEH-HMD a minimum of five days prior to beginning field activities. The report will be completed within one month of the completion of fieldwork. /T CORPORA TION C:\My DocumentsTrojectsTort of Stockton\Well Install\workplan.doc Rev.0,4/9/01