The Baldwin County Landfill marks a historical final closure as not only the first of its kind in the state of Georgia, but one of the first in the country to feature an entirely new landfill design process utilizing the ClosureTurf® system. Featuring an innovative technology, called ArmorFill™, the system eliminated the need for diversion berms, benches and down chutes by completely changing the hydrology methods in the traditional design.
In 2016, Baldwin County Board of Commissioners sought a design-build option for the closure of the 21.5 acre, Phase 3 Union Hill Church Road landfill. Oasis Consulting Services, a metro-Atlanta based woman-owned engineering consulting firm, was awarded the contract and obtained the Georgia Environmental Protection Division (EPD) approval of ClosureTurf in lieu of a traditional vegetated cap.
“We will probably make history. This is the first municipal solid waste landfill that has been closed in the state of Georgia with this process. We already have several individuals from several states that have come down and visited. It will be a showplace for the state of Georgia.” – Ralph McMullen, Baldwin County Manager
With SPLOST funds stretched, the county was relieved that the design-build solution from Oasis came in $1.5 million under traditional procurement. The approved ClosureTurf® system attributed to much of the cost savings. It eliminated the standard USEPA costly, lowpermeability clay liner, as well as vertical in-waste gas collection wells. But the real distinctive advantage was the use of ArmorFill™, an innovation created by Watershed Geo to enhance the hydraulic benefits of ClosureTurf. ArmorFill is an environmentally-friendly binding agent that is added to the top protective sand infill layer of the system. Even with slopes steeper than 3:1 in some locations, ArmorFill allows the entire cap to sheet flow to the perimeter ditches, eliminating the need for diversion berms (used to combat drainage length) and downslope channels (energy dissipation). This cutting edge design ultimately created a domino effect in cost savings and risk management for the county.
“We feel that this system and this process is not only going to save us money, but there is some dirt out there that we can’t stabilize and we could spend hundreds of thousands of dollars going back repairing, cutting grass, etc.,” McMullen said. “Every time you went out there, there would be some other repair.”
Oasis was able to complete the installation in about half of the time required for prescriptive caps. In addition to design and construction savings, future maintenance will be drastically reduced during the long-term post closure care period. The surrounding environment will also benefit, especially water quality, as a result of two key factors: the avoidance of fertilizers that
will not be necessary to grow and maintain grass; and the elimination of soil erosion and sediment-laden runoff from the cap.
As acknowledgement for their innovative approach, Baldwin County and Oasis Consulting Services was awarded the 2017 Georgia Chapter American Public Works Association engineering award for innovative, small/rural community projects.