Hazardous waste sites are regulated under two separate legislative acts: the Comprehensive Environmental Response, Liability, and Compensation Act (CERCLA) or Superfund and the Resource Conservation and Recovery Act (RCRA). In general, the former sites are usually no longer active whereas the latter are operating facilities. The likelihood for hazardous waste sites to cause harm to humans and/or the environment is largely evaluated via human health and ecological risk assessments, respectively.

Hazardous waste site ecological risk assessments (ERAs) have three main components: problem formulation, analysis, and risk characterization. The purpose of ERAs is to qualitatively and/or quantitatively evaluate the actual or potential impacts of site-related contaminants on non-cultivated plants, animals (other than humans and domesticated species), and biotic communities and ecosystems. Such realized or potential impacts are referred to as ecological effects and their assessment in ERA is limited to establishing the likelihood that they are or could be caused by one or more contaminant stressors.

The focus of an ERA is the assessment endpoints which are explicit expressions of the environmental values to be protected and operationally consist of an entity and attribute, generally within a specified geographic context (USEPA 1998). An example assessment endpoint is the survival and reproduction of songbirds at CGT Superfund Site which are appreciated by an active local Audubon Chapter. A major part of the ERA is deciding which elements of the ecosystem will be selected for evaluation and potential protection. Environmental values are selected using three criteria: (1) ecological relevance, (2) susceptibility to site associated known or potential contaminants, and (3) relevance to management goals.

In 2003, the Risk Assessment Forum (RAF) published Generic Ecological Assessment Endpoints (GEAEs) for Ecological Risk Assessment, a document that presented a set of generic ecological assessment endpoints (GEAEs) applicable to a wide variety of assessment scenarios. It also provided guidance for using these GEAEs to develop robust, assessment-specific endpoints.

The RAF expanded this document in July 2016 by publishing Generic Ecological Assessment Endpoints (GEAEs) For Ecological Risk Assessment: Second Edition with Generic Ecosystem Services Endpoints Added. This 2^nd edition augments the previous document by adding generic ecosystem services assessment endpoints (ES-GEAEs) intended to complement conventional GEAEs by extending ecological assessment endpoints to goods and services that benefit humans and may be economically valued by humans. For example, at CGT Superfund Site, a GEAE would be the population and diversity of birds recorded by the local Audubon Chapter. In addition to listing several generic ecosystem services assessment endpoints, the document explains how ecosystem services can be used as ecological assessment endpoints and provides examples of their uses and benefits such as support for cost-benefit analysis, assessment of risks to public welfare, clarification of the value of environmental protection, and support for natural resource damage assessments.

Using ecosystem goods and services as assessment endpoints provides ERA outputs society can appreciate and readily value. Generic ecosystem service assessment endpoints can help guide ERA planning when they are considered during problem formulation by tailoring the endpoints to the specific environmental and decision contexts. Ecosystem service assessment endpoints can complement conventional ecological assessment endpoints by clarifying to stakeholders and the public otherwise hidden benefits and costs a decision will have on society.

Incorporation of ecosystem goods and services into the ERA process allows human and ecological well-being to be considered concurrently during the remedial decision-making process. This integrated evaluation can provide valuable information and insights on environmental, economic, and societal factors needed to better inform decision-making. Models addressing ecosystem goods and services can greatly assist human/ecological integration throughout the ERA process from helping to identify and articulate relevant environmental values during the planning and problem formulation phases of ERA to providing means to qualitatively and/or quantitatively evaluate and compare ecosystem goods and services supported or generated by the assorted remedial decision options under consideration during risk characterization.

USEPA,1998. Guidelines for Ecological Risk Assessment. EPA/630/R-95/002F. Washington, DC: Risk Assessment Forum. Available: http://www.epa.gov/raf/publications/guidelines-ecological-risk-assessment.htm

USEPA, 2003 Generic Ecological Assessment Endpoints (GEAEs) For Ecological Risk Assessment. EPA/630/P-02/004F. Washington, DC: Risk Assessment Forum.

USEPA, 2016 Generic Ecological Assessment Endpoints (GEAEs) For Ecological Risk Assessment: Second Edition With Generic Ecosystem Services Endpoints Added. EPA/100/F15/005. Washington, DC: Risk Assessment Forum.

U.S. EPA. 2017. Engineering Forum Issue Paper: Ecosystem Services at Contaminated Site Cleanups. EPA 542-R-17-004. Available: https://semspub.epa.gov/work/HQ/100000459.pdf