Ecological: Problem Formulation
An initial step of an Ecological Risk Assessment (ERA) is to decide which components of an ecosystem (the sum of all the living organisms and the physical factors in a particular area) should be protected: in other words, what species should be the focus of the ERA. This initial step is part of Problem Formulation, which includes the development of a conceptual model: a representation of how the particular contaminants at a site are expected to behave in the environment.
The conceptual model is based on fate (e.g., does a contaminant break down in the environment or is it persistent?) and transport (how does a contaminant move through the environment and where does it end out?). The purpose of the problem formulation and the conceptual model is used to narrow attention to the animals and/or plants likely to be exposed to the contaminants at the site. In risk assessment language, the species that may be exposed to contaminants are called "receptors".
For this step, the risk assessor gathers information about the site that can help determine the potential risk to plants and animals found at the site being studied. Information can come from a variety of sources, including a site visit, historical information, and data from previous sampling of the area. The following issues should be addressed:
- Environmental setting;
- Contaminants known or suspected to be at the site;
- Contaminant movement physically within the site and through the local food chain;
- What plants and animals may be harmed by contaminants at the site;
- How the plants or animals come in contact with the contaminants;
- What are the effects on the plants and animals that are exposed.
Documents | EPA Links | External Links
- Ecological Assessment of Superfund
Sites: An Overview (PDF) (8 pp, 67K, About PDF)
Eco Update, December 1991
This EcoUpdate bulletin describes the components of the ecological risk assessment process and how they fit into the Remedial Investigation/Feasibility Study process.
- Ecological Risk Assessment
and Risk Management Principles for Superfund Sites, (Issuance
of Final Guidance) (PDF) (9 pp, 1MB, About PDF)
October 7, 1999
Guidance intended to help Superfund project managers to make ecological assessment decisions that are consistent across the United States and are transparent to the public.
- Ecological Risk Assessment Guidance
for Superfund: Process for Designing and Conducting Ecological
Risk Assessments - Interim Final
June 1997, EPA 540-R-97-006
These proposed guidelines are EPA's first Agency-Wide Ecological Risk Assessment Guidelines. They are broad in scope, providing general principles and providing numerous examples to show how ecological risk assessment can be applied to a wide range of systems, stressors, and biological spatial/temporal scales.
- ECO Update Bulletin Series
EcoUpdates are a series of bulletins which provide information on various aspects of Ecological Risk Assessments, including toxicity testing, the role of the Biological Technical Assistance Group (BTAG), field studies, and screening level risk assessments.
- Guidelines
for Ecological Risk Assessment
These Agency-wide guidelines are provided to improve the quality and consistency of EPA's ecological risk assessments. The Guidelines expand on and replace the 1992 report Framework for Ecological Risk Assessment.
- Role of Screening Level ERAs
and Refining Contaminants of Concern in Baseline Ecological Risk
Assessments (PDF) (4 pp, 364K, About PDF)
This EcoUpdate bulletin describes the process and purpose of the screening level ecological risk assessment, which is the first steps in a ecological risk assessment at a site, and how the list of COCs can be refined to include only those contaminants that may pose a risk.
- Role of the Ecological Risk Assessment
in the Baseline Risk Assessment (PDF) (2 pp, 180K, About PDF)
OSWER Directive 9285.7-17, August 12, 1994
Describes the process and purpose of baseline ecological risk assessments, which, if required, come after screening level risk assessments.
- Screening
Level Ecological Risk Assessment Protocol
1999
This is a guidance document that describes the process used in conducting ecological risk assessments at Hazardous Waste Combustion Facilities.
- EPA
Region 5 Ecology Technical Center Ecological Risk Assessment
Overview of ecological risk assessment process in Superfund, regional case studies, toxicity profiles, and regional contacts.
- Greenbook Pesticide
Labels and MSDS, EPA's Pesticide Program, PPIS Data, Biopesticides,
and RED Pesticide Summaries
EPA pesticide news stories, summaries, and featured sites.
- SW-846,
Test Methods for Evaluating Solid Waste, Physical/Chemical Methods
SW-846 contains over 200 documents, including the Table of Contents, Disclaimer, Preface, Chapters One through Thirteen, and many different methods for the sampling and analysis of wastes. All of the documents found in the Third Edition of SW-846, as updated by Updates I, II, IIA, IIB, III and IIIA, are located at this site.
- ATSDR's Toxicological Profiles
Link to information on toxicological effects caused by hazardous chemicals found at National Priorities List site.
- DEQ Information
Link to U.S. Fish & Wildlife Service's Division of Environmental Quality.
- The DOE Technical Standard, A Graded Approach for
Evaluating Radiation Doses to Aquatic and Terrestrial Biota and the RAD-BCG Calculator
Link to Department of Energy's procedure for investigating radiation exposure to aquatic and land plants and animals.
- EC Info and Literature From Region 2 EC Program
Link to U.S. Fish & Wildlife Service's Environmental Contaminants program.
- Guidelines for Interpretation of Residues in Biota, Water, and Sediments from USGS-BRD
National Irrigation Water Quality Program, Department of the Interior
- National Pesticide Information Center (NPIC)
A cooperative effort of Oregon State University and the U.S. Environmental Protection Agency (800-858-7378).
- Oak Ridge National Laboratory - Ecological Risk Analysis: Tools and
Applications
Link to guidance, screening benchmarks for various categories of plants and wildlife, and examples of completed ecological risk assessments.
- Oak Ridge National Laboratory: Toxicology and Risk Analysis Section
The Risk Information Web Server is part of the Toxicology and Risk Analysis Section, in the Life Sciences Division, at the Oak Ridge National Laboratory (ORNL). Page lists several information resources.
- PCB
Review by Heidi Fieldler
A general overview of Polychlorinated Biphenyls (PCBs).
- TOXNET (including TRI), Extoxnet and Extoxnet-pesticides
Provides a variety of information about pesticides.
- USDA Pesticide Info
Each fact sheet (issued by the U.S. Dept. of Agriculture Forest Service) provides information on forest and land management uses, environmental and human health effects, and safety precautions for various pesticides and their formulations.
- USGS - Contaminant Reviews
Contains the 35 reports in the Contaminant Hazard Reviews (CHR) originally published between 1985 and 1999 in the U.S. Dept. of the Interior Biological Report series, which include information on selected inorganic and organic chemicals and ionizing radiation.
- USGS Acute Toxicity Database
This database summarizes the results from aquatic acute toxicity tests conducted by the USGS Columbia Environmental Research Center located in Columbia, Missouri. The acute toxicity test provides a relative starting point for hazard assessment of contaminants and is required for federal chemical registration programs.