Suitability of the Solid Waste Utilization in Geotechnical Applications from a Viewpoint of Environmental Risk

Solid waste materials have been widely utilized as construction or geotechnical materials. Generally, regulatory leaching tests are performed to characterize the leaching potential of the constituent of concern (COC) contained in waste materials. However, the actual leaching concentration depends on the given field condition, and the environmental risk is difficult to be evaluated quantitatively. In this paper, leaching tests on steel slag and municipal solid waste incinerator ash slag are conducted, and a simplified method is proposed to assess the environmental suitability of these materials utilized as aggregate for the road base construction. It was assumed that the infiltration due to the precipitation led to the release of COC and the contamination of the subsurface. Environmental suitability was judged based on the potential human health risk by the intake of COC estimated from the results of laboratory column leaching tests and advection-dispersion chemical transport analyses. The risk estimated in the reuse of steel slag was 10^–4 order for groundwater consumption when the fluoride are leached under the given conditions.