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WASTE DISCHARGE REQUIREMENTSORDER NO. R5-2003-0020 -9- FOR COUNTY OF SAN JOAQUIN FOR CONSTRUCTION, OPERATION, CLOSURE AND EVALUATION MONITORING FOOTHILL SANITARY LANDFILL, MUNICIPAL SANITARY LANDFILL SAN JOAQUIN COUNTY engineered alternative is consistent with the performance goals of the prescriptive standard and affords equivalent protection against water quality impairment. 55. The leachate collection and removal system collection components consist of (from top to bottom): • 2 -foot thick soil operations layer; • 8-oz/sy nonwoven geotextile separator/filter; • 0.75 -foot -thick gravel drainage layer on base areas, and a geocomposite drain on the side slopes; and • Leachate collection troughs with 4- and 6 -inch -diameter lateral and header piping, surrounded with drainage gravel. 56. Each lateral leachate pipe is equipped with a pipe riser at each end for inspection, and cleaning if necessary, during the operational life of the module. A wire rope or cable will also be installed in each leachate lateral pipe to enable pull through of a video camera for LCRS inspection, if necessary. 57. All lateral and header leachate pipes are sized for flow capacities at least twice peak design flows from modeled "worst case" peak leachate production. The peak monthly leachate production, based on leachate removal records at the nearby North County Recycling Center and Sanitary Landfill is 200,000 gallons per month. 58. A 4 -foot deep leachate removal sump allows for a 3 -foot depth of leachate over a 2 -foot deep monitoring trench, without leachate backup into the LCRS collection troughs. A leachate pipe riser is provided for leachate monitoring and removal. The leachate removal pump system includes leachate level monitoring sensors, pump, automatic pump controls, and a flow system to record leachate volumes removed. An above ground leachate storage tank facility will receive leachate pumped from the sump, in advance of leachate handling for disposal. 59. The sump area is underlain with a secondary composite liner system, equipped with a monitoring sump and pump system to provide additional protection against the higher leachate head necessary within the leachate sump area. The system is designed to remove, far in excess of estimated peak flows, to preclude leachate head build-up on the base liner beyond the limits of the sump. A monitoring riser 12 inches in diameter is provided to enable monitoring for leachate, and its removal, if present. 60. Construction will proceed only after all applicable construction quality assurance plans have been approved by Executive Officer.