Responding to the Smallest Consequential Quantity of Soil Contamination

Abstract

Contamination in an abundance that is sufficient to threaten human health or the environment is herein termed consequential contamination. Both intuition and the precautionary principle support the need for a diligent sampling effort to ensure appropriate action is taken when consequential contamination is present. However, the most common approach to sample plan design inherently assumes the absence of discovered contamination is sufficient evidence to conclude the absence of consequential contamination. This assumption is indefensible if it can be reasoned that consequential contamination might exist between sampling locations. It is prudent that both soil characterization and rules for decision making minimally provide an acceptable chance of responding to the reasonably conceivable smallest consequential quantity of contamination. A conceptual model for a smallest consequential quantity of contamination is defined by a probability density function and an area-fraction function. Use of these functions to evaluate and prepare sample plan designs is demonstrated. The discussion presents the method’s value, concerns, and limitations.