Ecological Risk Assessment and Injury Assessment for Sediment Sites: Good Science or Good Science Fiction

摘要

Background/Objectives. The Daubert Standard, which was born out of a ruling by the United States Supreme Court, establishes that expert testimony and experts adhere to good science and good scientific methodology. Litigation associated with sediment remediation projects frequently involves estimation of risks and injuries to ecological resources. The validity of the scientific methodology underlying parts of the ecological risk assessment (ERA) and injury assessment is often not well understood, which can result in an overreliance on the conclusions of these assessments. Approach/Activities. Risks are frequently estimated as a component part of remedial investigations using technical methods for ERA. Injuries are assessed in natural resources damage assessments (NRDA) typically using techniques very much like the ERA. ERAs and injury assessments are technical endeavors that if not approached properly can create the illusion of, and sometimes have pretense to, good science. ERAs often contain hypotheses; myriad numbers and calculations; scientific references; graphs; dueling Ph.D.s; etc. However, these assessments often lack suitable rigor for their intended purpose and do not adhere to sound scientific methods. Consequently, ERAs generated through remedial investigations rarely meet the Daubert Standard. These limitations are due in large part to the guidance for conducting ERAs and, by extension, injury assessments. In this presentation, we will identify several methods commonly used to assess risk and injury to ecological resources and identify and discuss the limitations of these methods relative to the Daubert Standard. As a specific example, we examine the underlying toxicity data and assumptions used to develop commonly used sediment quality benchmarks (SQBs), which are widely used to establish cleanup objectives for sediment and aquatic systems and as a basis for natural resource damage claims. As our review demonstrates, the development of SQBs fails to meet the Daubert Standard. Rather, SQBs are more properly classified as a combination of conservative regulatory policy and limitations inherent in the data set from which SQBs are derived. Results/Lessons Learned. A better understanding of the strengths and limitations of SQBs, the ERA process, and injury assessments provides professionals working on sediment projects with the knowledge necessary to help ensure the activities completed on their projects are sufficient for their intended use. We also discuss the implications in environmental litigation of ERAs and injury assessments, which lack the scientific rigor to meet the Daubert Standard.