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PHASE 2 INVESTIGATION OF EXTENT OF CLOSURE CAP AND HEALTH AND SAFETY PLAN CORRAL HOLLOW SANITARY LANDFILL PURPOSE The purpose of this work is to establish the maximum extent of the new closure cap that must be placed to ensure that all refuse at the eastern side of the Corral Hollow Landfill is beneath the closure cap. PROCEDURE The extent of the closure cap will be assessed by pot-holing to a maximum depth of four feet with either a 12-inch diameter auger or small backhoe in the area west of the drainage ditch. These pot- holes will be located in line with phase I investigation excavation Nos. 2 and 3 (Figure 2), and at other locations as necessary to locate the western limit of the closure cap sufficient to ensure that any refuse along the road which is not now covered by closure cap will be covered. Excavation of refuse will be avoided. The soil shall be separately stockpiled from refuse if encountered, and shall not be commingled. The exposed sides of the pot-holes will be inspected for the layered prescriptive cover. After inspection, the pot holes will be repaired with a 2-inch thick granular bentonite abutting the clay barrier prior to replacing the excavated soil (Figure 3). Once the extent of the present closure cap has been delineated sufficiently to define the scope of work, the closure cap will be extended with geocomposite clay liner(GCL), and the drainage ditch relocated,to prevent further percolation of rainwater through the refuse. PROPOSED CORRECTIVE ACTION It is presently contemplated that corrective action will include extending the closure cap with GCL from the determined edge of the closure cap to the edge of the road. The approach will include the placement of(GCL) as hydraulic barrier from the eastern road edge to about 5ft overlapping the determined edge of the existing closure cap (Figure 4). About 26,000 sq ft of GCL liner will be used. The GCL liner will be rolled vertically and will have edges overlapped minimum of 6 inches with bentonite powder or fine granular between the overlap (Figure 5). Geocom osite Clay Liner Specifications GCL Model Bentofix Thermal Lock NWL orequivalent Bentonite content minimum 0.84 Ib/ft at 12% moisture Grab Strength (minimum)- 150 Ib average. roll value Permeability maximum 5x10" cm/sec Health and Safety Plan Solid Waste/Public Works Corral Hollow Sanitary Landfill Page 1 of 4 San Joaquin County October 25,2006