Ecological risk assessment procedures for US Army sites

This paper discusses U.S. Army guidance procedures for ecological risk assessments (ERA) for risk assessors under contract to the U.S. Army. Using this approach provides the Army with cost-effective, tiered procedures with which to direct and coordinate the scientific and technical efforts of contractors involved in ERA. Employing a common framework across sites can assure the Army that requirements of state and federal regulators are satisfied. The process described in this report follows the EPA ''Framework'' paradigm put forward in 1992. This document is a technical ''road map'', with examples and discussion of the thought process to lead environmental scientists through this effort. A tiered or phased approach has been put forward as a rational procedure by several scientists. The purpose of a tiered approach is to do the necessary and sufficient amount of work to characterize the risk to an ecological system with an acceptable degree of uncertainty. The assessment should proceed if risk is possible, but complete characterization of risk cannot be determined due to significant data gaps. The assessment should not proceed if no significant risk is apparent, or if the risk is so great that action (e.g., remediation, containment, etc.) is immediately warranted.