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4.1.4 Landfill Cover Properties The intermediate cover will nominally be two feet of fine-grained soil, compacted to 85% of maximum density. Because the Foothill Landfill has a long life, most of the LFG collection wells will be installed prior to final closure through the intermediate cover. Interim cover will be replaced in kind when wells are installed. Final cover materials for the landfill have not been selected. Final cover at the landfill will be designed and installed in accordance with applicable regulatory requirements. If installation of any of the GCCS components occurs after placement of the final cover, necessary repairs will be made to restore the cover to its prior condition. Cover construction will be performed under supervision of a construction quality assurance program. 4.1.5 Landfill Gas Control System Expandability Most of the LFG connection piping will be installed above ground to facilitate future expansion of the GCCS. If a header or lateral pipe becomes flow limiting because it is too small, either a parallel header will be installed or the pipe will be replaced with a larger size. As the landfill is expanded and additional LFG is collected, the GCCS size will be expanded to handle the additional LFG flow to maintain compliance with the requirements of §60.18 as required by the NSPS. 4.1.6 Condensate Management Condensate water collected at low points in the GCCS will be managed as leachate in accordance with the Waste Discharge Requirements (WDRs) issued by the Regional Water Quality Control Board. Condensate will either be delivered to the leachate collection and recovery system of a lined module, such as Module 1, or pumped directly to the leachate holding tank near the LFG flare station. The combined fluid in this tank will be delivered to the refuse of Module 1 or other lined module. Condensate will not be returned to Module "I", which is unlined. 4.1.7 Accessibility In general, the LFG transmission piping and LFG extraction wellheads will be above ground and provide easy access for modification, repairs, or extension. 4.1.8 Compatibility with Refuse Filling Operations Since most of the GCCS piping will be installed above ground, future connection of additional wells, sub -headers or laterals can be completed without excavation. Most of the LFG header pipes will be installed along the edge of the landfill and away from daily fill operations. In areas where additional refuse filling will be completed, wells will be disconnected, extended, and reconnected when filling is complete, connected to a lateral Foothill Sanitary Landfill 7 Public WorkstSolid Waste LFG CS Design Pian County of San Joaquin - March 10, 2005