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phases, as shown in the gas system Drawing Sheets G-1 through G-14, to minimize interruption of the gas system operation. The gas header, compressed air, and condensate conveyance lines will be re-installed and made operational prior to removal of the next phase. Any affected wells will be disconnected prior to removal of the header. Headers will be re-installed if the integrity of the pipe remains intact and if it can be adjusted to a positive grade. Otherwise, the pipelines will be replaced. The main header system will remain on-line during the entire construction period. All vertical gas collection wells in place in the Stage IA partial closure area will be protected during the placement of the final cover since control of landfill gas will continue during cover construction. The top of the vertical wells or well laterals will be extended through the final cover and then reconnected to the perimeter header system line as before. Any damaged or non-functional vertical wells or laterals will be abandoned and new replacements installed to provide gas extraction coverage. Final cover material will be placed and compacted by hand around the wells or vaults to protect against damage by earthmoving equipment. In order to keep the gas system operational during closure, temporary jumpers will be installed outside the closure area to maintain vacuum to the field. 3.9 LANDFILL GAS MONITORING SYSTEM 27 CCR, Section 20925 requires that subsurface gas monitoring wells (probes) be installed as part of closure around the perimeter of the landfill within the property limits but outside the limits of refuse with a spacing of approximately 1,000 feet. As discussed in Section 2.1, a landfill gas migration monitoring system is in place at the Forward Landfill and probes SGP-7A, SGP-8A, SGP-9A, SGP-1013, SGP-14, and SGP-13 are located near the perimeter of the Stage IA partial closure area as shown on Drawing Sheet 2. As part of closure, the existing probes will be protected in place. 3.10 GROUNDWATER/SURFACE WATER MONITORING SYSTEM Groundwater monitoring programs are currently being implemented on a quarterly basis at the Forward Landfill, as discussed in Section 2.2. Figure 4 shows the location of the existing groundwater monitoring wells. No modifications to the groundwater/surface water monitoring system are required as part of the Stage IA partial closure. Forward Landfill PFCPCMP 3-15 J:\Allied\Forward\2005.0051 Partial Closure\Partial Closure Plan\FL-sec3.doc:6/15/2005