SELECTION OF CONTAMINANTS AND RECEPTORS OF CONCERN FOR ECOLOGICAL RISK ASSESSMENTS USING THE PAIRED-COMPARISON TECHNIQUE (PCT)

A critical component of the ecological risk assessment process, identi fication of contaminants and receptors of concern, is currently lackin g an objective, data-driven, broadly applicable methodology. The paire d comparison technique (PCT) can be used to meet this need by providin g a standardized technique for making these decisions. PCT condenses t he decision-making process down to individual components and ultimatel y generates an objective ranking for each alternative based on pertine nt attributes. Factors considered in the PCT may be selected and weigh ted via a formal consensus building process which can incorporate stak eholder concerns. Once factors have been selected and weighted, each a lternative is ranked relative to each other alternative for each facto r. Each alternative ranking for each factor is multiplied by the facto r's weight and the weighted rankings are summed. These sums are then u sed to rank alternatives relative to one another. This ranking provide s decision-makers with a semiquantitative basis for making final decis ions, although the technique itself does not (and should not) actually make the decision. Several examples of the technique using actual Sup erfund site data are presented.