Contents Notes |
Landfill performance was investigated before the closure of a 4-ha (10-acre) experimental landfill site located in Boone County, Kentucky. The site contained a field-scale landfill and four smaller test cells filled with compacted municipal solid waste. From 1970 to 1980, the landfill was operated by the U.S. Environmental Agency (EPA) to monitor gas and leachate production. The current project was undertaken before the scheduled site closure to obtain information useful to designers of future landfill facilities. Information was developed on cover soils, refuse, leachate collection systems, and lining materials from the test cells. To examine and recover cell components, exploratory excavations were made through the refuse and base liners. Each of the cell elements (cover, refuse, liners, etc.) was thoroughly documented, and samples underwent extensive testing. The project included the recovery and detailed inspection of the cover soils and of the clay and synthetic liners that had been exposed to leachate for approximately 9 years. Although the cover soils were constructed to maintain tight permeabilities, a vertical seepage plane did develop over the project life. Both field and laboratory testing showed little degradation of the liners and no leachate migration through these materials. The physical appearance of the refuse was similar in all excavated cells and showed little vertical difference. Decomposition was limited primarily to food wastes. Isolated incidences of gravel cementation were found in the upper leachate drain of one cell. |