Challenge

The Sumter County Landfill was experiencing persistent water-management challenges, including ponding on the top deck and leachate outbreaks along the slopes. With groundwater impacts also a concern, the site required a closure approach that could improve performance and address underlying water-management issues. 

The closure strategy needed to address several interconnected objectives: minimize rainfall infiltration and associated leachate generation, improve stormwater conveyance and surface water control, and support effective landfill gas management. 

Solution

The site identified a remedial engineered cap as a solution. As part of the remedial closure strategy, ClosureTurf® as the engineered final cover system. This decision was based in part on experience with other engineered cap projects in Georgia and the system provided a closure approach designed to limit infiltration, protect against erosion, and reduce the maintenance associated with conventional vegetated covers.  

The project also incorporated several site-specific improvements. The top deck was regraded to provide a minimum 3% slope, a leachate collection toe drain was installed along the main slope, and the existing soil vapor extraction system was expanded. HydroTurf® was incorporated along the four downchutes to manage concentrated stormwater flows. 

Result

The completed project integrated the final cover, stormwater conveyance, leachate, and landfill gas management into a coordinated remedial closure strategy.  Together, the improvements were designed to minimize rainfall infiltration and associated leachate generation, improve surface-water management, and provide erosion protection.   

In addition to addressing the site’s immediate closure needs, ClosureTurf eliminated the need for mowing, fertilizing, and vegetative maintenance associated with a conventional soil cover and provides an opportunity to evaluate the closed landfill for future beneficial use, including renewable energy development.