Ecological Risk Assessment

An Ecological Risk Assessment (ERA) evaluates the likelihood that adverse ecological effects are occurring or may occur as the result of exposure to one or more stressors. In Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) or Resource Conservation and Recovery Act (RCRA) Corrective Actions, ERA specifically means a qualitative and/or quantitative evaluation of actual or potential impacts on plants and animals from restoration sites contaminants. This definition does not include humans or domesticated animals. For ecological risk to exist, the contaminant must have the ability to cause an adverse effect and there must be a completed pathway (e.g., ingestion, inhalation, touching, root uptake), as well as a high enough and long enough exposure to contaminants to cause the adverse effect.

The Army takes its commitment to protecting the environment, as well as human health, seriously the ERA helps determine if a risk to the environment exists at Army restoration sites. An ERA is an integral portion of the Remedial Investigation/Feasibility Study (RI/FS) process, and is designed to support risk management decision-making. The RI component of the process characterizes the nature and extent of contamination, and estimates risk to the environment from contaminants at or from the site. The FS component develops and evaluates remedial options to mitigate any existing or potential risk. Even though the majority of DoD sites are not designated as Superfund sites, ERAs are performed using the 1997 U.S. Environmental Protection Agency Ecological Risk Assessment Guidance for Superfund: Process for Designing and Conducting Ecological Risk Assessments, known as ERAGS.

Following the U.S. EPA OSWER Superfund guidance for ERAs, we utilize an eight-step process: (1) Screening-level problem formulation and ecological effects evaluation; (2) Screening-level exposure estimate and risk calculation; (3) Baseline risk assessment problem formulation; (4) Study design and data quality objective process; (5) Field verification of sampling design; (6) Site investigation and analysis phase; (7) Risk characterization; and (8) Risk management.

Step 3 may not be applicable, as Baseline ERAs (BERAs) are not always accomplished; often there is only a site-level ERA. However, the basic steps within Step 3 are examined, e.g., refinement of the preliminary Contaminants of Concern (COCs), literature search for known ecological effects of the species of concern at the site, contaminant fate and transport, the ecosystem(s) potentially at risk, complete exposure pathways, selection of assessment endpoints, refining the conceptual model, and possibly setting the scientific/management decision point (SMDP).

In 1993, the Army formed a group referred to as the Biological Technical Assistance Group (BTAG) to provide technical guidance to Army restoration project managers in the area of ecological risk assessment in response to BTAGs being formed at each of the U.S. EPA Regional Offices, but the Army BTAG was disbanded in 2008. For assistance with specific ERA issues, individuals or installations may contact the Army Public Health Center (APHC), U.S. Army Combat Capabilities Development Command Chemical Biological Center, the U.S. Army Corps of Engineers (USACE), or the USAEC individuals who specialize in risk assessment protocols, ecology, toxicology and natural resources.