Natural Resource Damages: Assessments
This webpage provides information about Ecological Risk Assessments (ERAs) and Natural Resource Damage Assessments (NRDAs) for Trustees and EPA staff. EPA recommends an ERA as part of assessing the impacts of site-related contamination.
ERAs evaluate the likelihood that adverse ecological effects are occurring or may occur as a result of exposure to physical stressors (e.g., cleanup activities) or chemical stressors (e.g., release of hazardous substances) at a site. These assessments often contain detailed information about the interaction of these stressors with environmental conditions at the site. The assessment process includes creating exposure profiles that describe the sources and distribution of harmful entities, identifying sensitive organisms or populations, characterizing potential exposure pathways, and estimating the intensity and extent of exposures at a site. ERAs are usually done during the remedial investigation and feasibility study (RI/FS) phase of the Superfund Response Process. ERAs can be done quickly for removal actions, if there is an eminent threat to ecological receptors. These instances are rare. Such ERAs follow the same process as long-term ERAs done during the RI/FS.
Ecological risk information may be part of an NRDA. Both EPA and Natural Resource Trustees benefit from sharing information and coordinating during ERAs. In October 1999, EPA released Ecological Risk Assessment and Risk Management Principles for Superfund Sites (PDF) (OSWER Directive 9285.7-28 P). This guidance directs Superfund site risk managers ans Trustees to coordinate EPA investigations of risk with Trustee investigations of resource injuries to make efficient use of federal and state funds.
An NRDA identifies additional actions, beyond the response needed, to address injuries to natural resources. Examples include actions needed to restore the productivity of habitats or species diversity injured by the past releases or to replace them with substitute resources. A Trustee may also seek compensation for the loss of injured natural resources from the time of injury until their full restoration by assessing lost services. CERCLA and OPA both include regulations for assessing NRD.