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LEACHATE COLLECTION AND RECOVERY SYSTEM - PROCEDURES & MAINTENANCE <br /> Facilities <br /> The leachate collection and recovery system(LCRS) for Module 1 was designed and constructed in <br /> accordance with Title 27, Section 20340(g). This system consists o£ <br /> • East/west oriented collection troughs running the entire length of Module 1 <br /> • A 4-foot deep sump at the southeast corner of the Module <br /> • A leachate removal pump installed in an 18-inch diameter HDPE pipe <br /> • A 2-foot deep secondary extraction trench beneath the primary composite liner, with 12-inch <br /> HDPE riser pipe <br /> • A pumping system that allows recording of leachate flows and volumes <br /> • A 10,000 gallon leachate storage tank located near the LFG flare station. <br /> The LCRS includes pipe risers at the end of each leachate lateral to enable video camera inspection of key <br /> portions of the pipe network. The moderate pipe bends of the risers allow cameras to be pushed several <br /> hundred feet into the network to record pipe conditions and depth of flows in the LCRS network. A wire <br /> rope is installed in each leachate lateral pipe to enable the pulling of a camera through the entire length of the <br /> risers. <br /> Disposal: Return of Leachate to the Refuse <br /> Leachate drains by gravity to the Module 1 sump. A pump within the sump either returns the leachate to the <br /> refuse of Module 1 or delivers it to the 10,000-gallon storage tank from which it is removed by water truck <br /> and either returned to the refuse if Module 1 or used as dust control over Module 1. At no time is leachate <br /> returned to Module"I". <br /> The pump operates automatically,based on leachate level within the sump. Control points for the pump are: <br /> Pump Off: 17" Pump On: 43" Alarm:48" <br /> Operation of the pump is conditional upon sufficient water in the sump and available capacity in the leachate <br /> tank. A high level alarm is activated if the leachate exceeds the alarm level. The alarm level is chosen to <br /> maintain the hydraulic head on the module base below the maximum allowed 12 inches. <br /> The leachate storage tank facility includes secondary containment(consisting of a concrete vault surrounding <br /> the tank) and a truck loading area. Controls for the leachate storage tank include a high level sensor that will <br /> sound an alarm and disable the leachate sump pump if the level in the tank nears the top of the tank. This <br /> prevents overtopping of the tank. However, the secondary containment will retain any leachate in case of <br /> failure of those controls. <br /> Leachate System Monitoring and Maintenance <br /> The flow rate provided by the sump pump is tested at least monthly. If no other causes are apparent, then a <br /> decrease in pumping rate will indicate the need to clean a filter or to investigate pump wear. <br /> Foothill Sanitary Landfill 13 Department of Public Works/Solid Waste <br /> 1s`Semester 2012 Groundwater Monitoring County of San Joaquin—July 17,2012 <br />