When Stovall Landfill, Prescott, Ark., reached its capacity, the owners implemented a closure plan to minimize water infiltration, control erosion and protect the high groundwater table from leachate infiltration. The landfill covers 11.5 acres and contains approximately 450,000 yd3 of nonhazardous, Class 3 commercial/industrial solid waste generated by a nearby manufacturing facility.
The landfill closure design team specified a cap system based on an ethylene propylene diene terpolymer (EPDM). This was the first EPDM geomembrane landfill cap permitted in the U.S. After evaluating several options, a Firestone EPDM Geomembrane was chosen based on its quality and performance history in both exposed and buried containment applications in the U.S. and Europe. The site had poor subgrade conditions, so the tensile load strain and puncture resistance of the EPDM geomembrane were significant factors in its selection and installation.
Faced with high winds at the time of the installation, the geomembranes flexibility was a significant advantage. It allowed the geomembrane to conform closely to the subgrade, providing increased surface friction to resist wind uplift. After installation, soil and grass was placed over the membrane. Today, the site is barely distinguishable from the lush fields nearby.