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SECTION 5 Containment System The southern portion of the WMU FU-06 containment system consists of a liner and LCRS on the base of the unit and a composite side slope liner on the southern excavation slope. The northern slope in the southern portion of the cell incorporates an interface liner to separate Class III wastes in the former Austin Road Landfill from the overlying Class II wastes to be placed in WMU FU-06. The northern portion of WMU FU-06 is located on the top deck of the former Austin Road Landfill. The interim final cover serves as the base liner for this portion of the cell. A LCRS will be placed over the interim final cover. Leachate will drain to header pipes located along the southern termination berm and then routed via a solid 3-inch HDPE pipe to a temporary leachate storage tank. Once the northern and southern portions of WMU FU-06 are constructed and approved for disposal, the liners and LCRS in the northern and southern portions will be connected and the leachate will drain to the sump in the southern portion of WMU FU-06. The area where the northern and southern portions of WMU FU-06 will be connected is a relatively flat area. The existing southern termination berm in the northern portion of WMU FU-06 will be removed in the connection zone. The clay liner in northern portion of WMU FU-06 will be transitioned to a 60-mil HDPE geomembrane and extended to meet the geomembrane liner in the southern portion of WMU FU-06. The gravel layer in the northern portion of WMU FU-06 will be extended to connect to the geocomposite drainage net at the top of the northern slope in the southern portion of WMU FU-06. Leachate from northern portion of WMU FU-06 can then flow directly into the southern portion of WMU FU-06 and to the sump. Because the connection area is relatively flat and is underlain by refuse in the former Austin Road Landfill, a geogrid is incorporated in the connection area to support the overlying liners and LCRS systems. Once the northern portion of WMU FU-06 is approved for disposal, Class III refuse will be placed above the northern portion. The south facing slope of refuse placed in the northern portion will be lined with an interface liner to separate the Class III refuse in the northern portion from the Class II refuse in the southern portion. The LCRS of the interface liner net will overlap the northern slope of the southern portion of WMU FU-06 to allow leachate to drain to the WMU FU-06 base and sump. The base liner system for the southern portion of WMU FU-06 consists of the following, from bottom to top: • Prepared subgrade; • Minimum 2-foot thick compacted clay liner with a maximum field hydraulic conductivity of 1 x 10-7 cm/sec; • 60-mil,double-sided textured HDPE geomembrane liner; • Cushion geotextile; • One-foot thick blanket gravel and pipe network drainage layer with a minimum hydraulic conductivity of 0.1 cm/sec; • Nonwoven geotextile filter fabric; WMU FU-06 REPORT6 5-1