Landfill cover system for minimizing the geo-environmental impact

Effectiveness of landfill cover systems is presented based on the experimental and theoretical study. Since the incinerator ash is disposed in most landfills in Japan, the leaching of inorganic chemicals (heavy metals, salts) is an important geo-environmental concern. Reducing the infiltration into waste by cover systems is expected to promote anaerobic condition, which might result in minimizing the leaching potential. However, the effectiveness of covers has been discussed only from the viewpoint of water balance but not from such chemical and bio-chemical aspects. Thus, the objectives of this paper are (1) to experimentally examine the possibility of utilizing sludge materials (paper sludge and construction sludge) as barrier layer for the landfill cover system (2) to parametrically evaluate the performance of sludge barrier layer under the Japanese climate conditions, and (3) to evaluate the effect of anaerobic (reduction) condition resulting from the reduced infiltration by cover systems.