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2.3 DRILLING The wells will be drilled by a licensed drilling Contractor. Depths of the new dual LFG extraction wells are above seasonal ground water table (Figure 5). The drill cuttings while drilling will mostly be refuse. Refuse and soil with refuse drilled out will be placed in a dumpster bin and then disposed off-site. A boring log will compiled during drilling. 2.4 WELL CONSTRUCTION It is anticipated that the dual LFG extraction wells will be constructed immediately after drilling. A. UNCOMPLETED BORINGS If a well borehole is not drilled by the end of the day and is to be left open, the well borehole opening will then be securely covered for safety and to prevent LFG escaping into the atmosphere. Either a 8'x4'x Y2" inch thick sheet of plywood with weights may be placed over the borehole or the drilling auger may be left in the borehole with its top covered. The drilling area will be cordon off with safety cones and caution tape. B. ABANDONED BORINGS Abandoned borings will be backfilled in the native soil with neat cement and with soil in refuse (Figure 10). The barrier layer in the abandoned boring will be repaired with bentonite. 2.5 WELL CONNECTION A. WELL LATERALS The new dual LFG dual extraction wells will be connected to the existing LFG system header with a 3-inch diameter HDPE lateral pipe (Figure 2, 3 and 6). Lateral trenches in the vegetative layer will be carefully excavated to avoid disturbance to the barrier layer (Figure 7). B. EQUIPEMENT SWD's contractor will provide all necessary equipment for this project. It is anticipated that an excavator mounted drill rig will be used for drilling. A backhoe or equivalent will be used to excavate lateral trenches. Work Plan—Dual LFG Extraction Well Installation San Joaquin County Harney Lane Sanitary Landfill Public Works Department Revised 10-30-09 3 Solid Waste Division