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01 0 WORK Forthe SAMPLING OF •' OF • NORTH• March 28, 2007 The purpose of this work plan is to describe the procedures to collect a sample of the geonet drain fabric and the non -woven geotextile above the HDPE liner of Module 3 at North County Recycling Center and Sanitary Landfill (Figure 1). Presently, the top deck of Module 1 (previously identified as Modules 1&2) is graded to drain from west to east, with the western shoulder of the landfill now at the present permit limit of 190 ft. above mean sea level (msl). This drain direction is advantageous at present because it drains storm water more directly to the temporary sedimentation pond on the eastern side of the property (Figure 1), and is consistent with the present Closure Plan and the present permit limit. However, this drain pattern conflicts with the future development of the landfill to the height limit (220 ft. msl) of the Environmental Impact Report certified in December 2006. Constructing the Modules to the east of Modules 1 and 3 to the anticipated greater height while retaining the present west -to -east drainage will create a drainage Swale near the center of top of the landfill. This is an unusual configuration with significant potential for erosion. A more beneficial drainage direction would be east -to -west on the top of those Modules towards the nearest edge of the landfill. Changing the drain slope will require the placement of additional refuse over Modules 1 and 3. However, a slope stability analysis is required before additional fill is placed. The County has engaged Shaw Environmental, Inc to perform this analysis. Shaw staff have stated that this analysis requires additional knowledge of the shear and frictional characteristics of the synthetic fabrics (the geonet drain fabric, and the non -woven filter fabric) above the HDPE liner, and that samples of fabric over Module 3 would be sufficient. Therefore, the County proposes to collect a sample of these fabrics from Module 3 to enable that analysis. The fabrics will be sampled from an easily accessible area at the southeast corner of Module 3 (Figures 1 and 2). The sampling area is near the anchor trench where refuse has yet to be placed, so that only the operations soil, approximately 2 -ft. thick, need be removed. This location also avoids conflict with the leachate and landfill gas (LFG) risers. Work Plan -Fabric Sampling at Module 3 Solid Waste/Public Works North County Sanitary Landfill Page 1 of 2 San Joaquin County — March 28, 2007