Risk Assessment and Management in Metal-Contaminated Sites

Abstract

How clean is clean? How clean is clean enough? These are indications of the changing cleanup paradigm being faced by the scientific community, policymakers, and industry. A decade or so ago policymakers believed that cleanup activities should use background (or baseline) values of contaminants in soils as an index of a successful cleanup (e.g., in the case of soil washing/flushing or excavation). Today, the cost and even the best available remedial technologies may not be able to achieve such rather wishful levels without destroying the integrity of the contaminated site. This has led to the current cleanup questions: How clean is clean enough? In other words, how much risk reduction is acceptable without reaching the background level? Or can standards be tailored to specific land use?