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Foothill Sanitary Landfill 23 Department of Public Works/Solid Waste <br />First Semiannual 2025 Groundwater Monitoring ©2025 County of San Joaquin. All rights reserved. <br /> <br />12.0 LEACHATE COLLECTION AND RECOVERY SYSTEM - <br />PROCEDURES AND MAINTENANCE <br />12.1 Facilities <br />The leachate collection and recovery system (LCRS) for LF-2 Module 1, 2A and 2B were <br />designed and constructed in accordance with CCR Title 27, Section 20340(g). This system <br />consists of: <br /> East/west oriented collection troughs running the entire length of Modules 1 and 2 <br /> A 6-foot deep sump at the southeast corner of the Module 1 <br /> 4-foot deep sumps at the southeast corners of Modules 2A and 2B <br /> Leachate removal pumps installed in an 18-inch (Mod 1) and 24-inch (Mod 2A and 2B) <br />diameter HDPE pipes (risers) <br /> A 2-foot deep secondary extraction trench beneath the primary composite liner, with 12- <br />inch (Mod 1) and 18-inch (Mod 2A and 2B) HDPE riser pipe <br /> A pumping system that allows recording of leachate flows and volumes <br /> Two 10,000-gallon leachate storage tanks located near the LFG flare station. <br />The LCRS includes risers at the end of each leachate collection lateral to enable video camera <br />inspection of key portions of the pipe network. The moderate pipe bends of the risers allow <br />cameras to be pushed several hundred feet into the network to record pipe conditions and depth <br />of flows in the LCRS network. A wire rope is installed in each leachate lateral pipe to enable the <br />pulling of a camera through the entire length of the risers. <br />12.2 Disposal: Return of Leachate to the Refuse <br />Leachate drains by gravity to the Module 1, Module 2A, and Module 2B sumps. A submersible <br />pump within each sump returns the leachate either to the refuse of Module 1, 2A, and 2B via <br />injection wells located on the top deck or via piping to the two 10,000-gallon storage tanks, from <br />which it can be removed by water truck and either returned to the refuse of Module 1, 2A, and <br />2B or used for dust control on those modules. At no time is any leachate returned to unlined <br />Module “I”. <br />The pumps operate automatically, based on leachate levels within the sumps. Control points for <br />the pumps are shown in the table below, but subject to changes/adjustments based upon <br />leachate generation rates.