Risk-Based Evaluation of the Surface Cover Technology of a Red Sludge Waste Disposal Site in Hungary

Abstract

During past decades, several million tons of aluminum industry wastes have been dumped, without a bottom lining system, right on the shore of the Danube River in northwest Hungary. The resulting red sludge ponds pose two major threats to the environment: drinking water resources could be polluted by infiltration, and wind erosion contaminated surrounding residential areas. Due to limited resources, the latter issue was not addressed until the present owner and operator of the industrial site took charge.. To solve the problem of cost, the operator applied treated hazardous waste to form a surface cover for the already polluted site. His proposal to he use this technology at the site obtained all the necessary permissions for implementation. Due to a new piece of national regulation, risk-based evaluation of the remediation technology became required. The task of the risk assessment was to compare the original (uncovered) state of the site and its human health risk to the remediated (covered) situation, where the covering layer consisted of manipulated hazardous waste material. This interesting case study of risk analysis, beside its challenge to the assessor’s expertise, raised several questions regarding environmental ethics, environmental stewardship, and responsibilities.