Leachate Control. A primary pathway for chemicals to migrate from the landfill to the surrounding environment is through contact with water. As described in Section 2, leachate resulting from the interaction of garbage and water can contaminate groundwater and surface water. Locations with high rainfall volumes, groundwater tables relatively near the surface, and nearby surface water bodies should be especially aware of the potential for off-site contamination through leachate. A fundamental step in leachate control is preventing leachate generation. Disposal of wet wastes (e.g., septage, wastewater) with other garbage should be avoided. Many of the sanitary landfill practices outlined above minimize leachate formation. When the area of the waste placement is reduced, less leachate will result. Waste compaction and cover soil application will reduce the amount of rainfall that infiltrates into the garbage and forms leachate. The landfilled waste should be graded to drain stormwater away from the waste, surrounding terrain should be graded to minimize the flow of stormwater onto the waste, promote drainage, and control runoff from the landfill. Standing water on, adjacent to, or near the landfilled waste should be avoided. The Subtitle D Part 258 landfill regulations for sites accepting MSW require a liner and an LCRS; thus, the leachate is removed from the landfill before it migrates into the underlying soil groundwater. Operators of disposal sites without a Subtitle D liner may still have the opportunity or need to drain leachate from the landfill. For example, as discussed later in this section, the Fukuoka-style landfill typically uses a leachate collection system placed above a natural earthen liner without the utilization of a geomembrane. However, in order to comply with federal regulations, the Fukuoka-style landfill would have to be constructed with a Subtitle D Part 258 liner. Furthermore, waste has to be covered to minimize odors and disease transmission. Subtitle D Part 258 requires that the depth of leachate on the liner be maintained at 30 cm or less; typically pumps are employed to convey leachate from the LCRS and comply with this regulation. Where possible, original site grades should be utilized so that leachate can be drained by gravity to comply with the 30 cm head on the liner requirement while minimizing costs. This is particularly the case for sites in remote, economically challenged locations. This should be part of the original planning of the dispos...
Leachate Control. The Landfill is expected to generate leachate, although after closure, the rate of generation is expected to decline. Moreover, the water quality of the leachate is expected to stabilize at some point and not require treatment under the appropriate State regulations. Until that point is reached, Xxxxxxxx will continue to operate the leachate treatment system. Leachate quality will be monitored in the same manner as for the operating phase. At the time that any waste cell reaches stability and leachate quality is within acceptable limits, Xxxxxxxx may apply to the Department of Health and County for permission to suspend treatment on that leachate.
