[co-author: Timothy Havranek]*
A broad range of reactions – from celebratory to alarmist – describe the workforce reductions and regulatory rollbacks proposed or currently underway at the U.S. Environmental Protection Agency (EPA). Notable concerns surround the agency’s decision-making process at contaminated sites. Regulatory rollbacks and a refocus on the President’s economic priorities may risk detracting from the EPA’s commitment to protecting the nation’s environment and the well-being of communities. If ‘taking action quickly’ is the EPA’s new guiding mantra, how will the agency fulfill its mission?
Quick actions are most attractive when they pinpoint high-value site cleanup decisions, safeguard human health and the environment, and accelerate the repurposing of previously contaminated sites for productive use. Even better are decisions that accomplish these outcomes at the lowest possible cost.
This article provides an overview of the various decision support tools available to the EPA and those in the environmental industry, along with suggestions for their usage.
The Path for Taking Action Quickly
The EPA has a well-established path for achieving the quick actions and cost-effective goals sought by the current administration. This path includes environmental decision support tools (EDSTs), which are frequently used to assess, manage, and remediate contaminated sites, particularly within the Superfund, RCRA (renamed in October 2024 as the Hazardous Waste Cleanup Program), and Brownfields programs. These tools facilitate data collection, analysis, modeling, visualization, and risk assessment.
EDSTs have evolved to systematically support the evaluation and selection of remediation strategies that balance economic, environmental, and social considerations. However, the quick actions sought by the current administration require understanding when to use these tools and recognizing the types of results they can provide.
In the context of decision-making, remediation projects can be categorized into two distinct phases: the aggregation phase and the evaluation phase. The aggregation phase involves collecting data to support informed decision-making. An example of an EDST during this phase is human health risk assessment (HHRA). Conversely, the evaluation phase assesses information on various decision alternatives to determine a preferred option. Cost-benefit analysis (CBA), which ranks alternatives according to their net additive value of benefits and costs, is an EDST commonly used during this phase.
The results produced by various EDSTs can also be categorized into two broad groups: those that evaluate remedy alternatives based on a single criterion and those that assess alternatives using multiple criteria. HHRA and CBA methods exemplify EDSTs that evaluate alternatives based on a single criterion. Multi-criteria decision analysis (MCDA), as the name implies, involves evaluating alternatives using multiple criteria.
Below is a list of EDSTs and closely related familiar tools often used in conjunction with environmental remediation projects. An indication of the decision phase and type of results is provided after the description of each method. The best results, in terms of achieving environmental, social, and economic goals, are obtained by combining the different analytical approaches.
Environmental Decision-Support Tools
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Uncertainty is inherent in environmental work and often influences decision-making. EPA’s remedial investigations/feasibility studies (RI/FS) guidance specifies approaches to uncertainty analysis. For example, Information Gap Decision Theory (IGDT) is a tool used to facilitate groundwater remediation decision-making at sites where data describing contaminant behavior and site conditions are limited i. (aggregation/single criterion)
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Net Environmental Benefit Analysis (NEBA) has become an important tool for determining effective response strategies for oil and chemical spills. NEBA systematically compares environmental trade-offs, including costs, of different remedies and response options relative to the consequences of inaction ii. (evaluation/single criterion)
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Risk of Remedy Analysis, or Residual Risk Analysis (RRA) evolved from risk management principles applied to contaminated sediment sites. RAA functions similarly to NEBA. RAA evaluates the trade-offs associated with post-remedy residual ecological and health risks, implementation costs, and long-term remedy efficacy iii. (evaluation/multiple criteria)
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Natural Resource Damage Assessment (NRDA) encompasses various tools employed by federal, state, and Native American trustees to quantify the harm to natural resources and services caused by chemical and oil spills and conditions at hazardous waste sites. Classical economic valuation methods are used to substantiate the public's claim for restoration or replacement of the injured natural resources iv. (evaluation/multiple criteria)
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Remediation spreadsheet tools, such as SiteWise and SRT, developed in the Department of Defense SERDP/ESTCP program, compare the environmental, social, and economic impacts of different groundwater and soil remediation technologies. These tools facilitate the selection of remediation options and strategies that minimize negative impacts while achieving cleanup objectives v. (evaluation/multiple criteria)
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Spill Prevention, Control, and Countermeasures (SPCC) Plans and Area Contingency Plans (ACPs) define how the EPA will initially respond to environmental emergencies, such as those associated with chemical and oil spills. SPCCs and ACPs provide a framework for developing response strategies. The US Army Corps of Engineers Formerly Utilized Sites Remedial Action Program (FUSRAP) is another example of contingency planning that invokes strategic, tactical, and operational decision-making objectives when preparing for contaminant releases, ensuring that response actions minimize environmental damage vi. (evaluation/single criterion, i.e. risk)
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Life cycle analysis (LCA) aggregates the environmental impacts of a system’s life cycle. A common output is the tons of CO2 equivalent associated with the life cycle of each alternative. (evaluation/single criterion)
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EPA’s Superfund Green Remediation program and Superfund Remedial Action Cost Engineering and Requirements (RACER) are examples of tools that integrate environmental, economic, and social considerations into remediation decisions and actions. These and related cost-benefit tools ensure that site cleanup does not unintentionally harm public health or the environment vii. (evaluation/multiple criteria)
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Multi-criteria decision analysis (MCDA) is a structured analytical framework for making complex decisions that involve competing objectives, multiple stakeholders, and significant uncertainties. MCDA integrates site-specific information from diverse sources to identify the preferred remedy alternative or rank options based on cost, environmental, governance, and social performance metrics 18. Another significant advantage of MCDA is that it includes a structured engagement process to capture the objectives, values, and preferences of stakeholders who may be affected by remediation viii. (evaluation/multiple criteria)
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Decision Support Systems (DSS) integrate assessment tools, databases, environmental models, and stakeholder inputs into the remediation of brownfields and contaminated sites. The Geophysical Decision Support System (GDSS) for environmental fate analysis, the Spatial Analysis and Decision Assistance (SADA) tool for environmental site assessment, and EPA Region 5’s Field Environmental Decision Support (FIELDS) Team for rapid site characterization are three examples of leveraging data, modeling, and spatial analysis to support site remediation ix. (evaluation/multiple criteria).
Environmental Justice Tools
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It would be remiss not to acknowledge the value of the Environmental Justice Screening and Mapping Tool (EJSCREEN) for identifying underlying health threats to communities posed by various environmental and social factors. CalEnviroScreen is another valuable resource. Determining whether the primary health risks stem from air, food, groundwater, or soil is important within the context of the CERCLA mandate for risk reduction x. (evaluation/single criterion, i.e., health risk)
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The Environmental Public Health Tracking Program (EPHT) collates health data, environmental hazards, and exposure information to create a clearer picture of the public health landscape concerning environmental risks. EPHT identifies vulnerable populations and, importantly, contributes to effective public health interventions at both the state and local community levels by diagnosing health impacts resulting from various types of environmental exposures xi. (aggregation/single criterion, i.e., health risk)
Familiar Risk Assessment Methods
Classical human health and ecological risk assessment has faced criticism—some of it warranted—for stating the obvious: contaminated sites contain potentially harmful chemicals. Although some EPA risk assessment guidance is outdated, advances in exposure models, fate and transport models, and toxicity assessment have improved the utility of risk assessment for characterizing the effectiveness of a selected site remedy.
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The Ecological Risk Assessment (ERA) toolbox provides a framework for evaluating the potential adverse effects of contaminants on ecosystems and, indirectly, human health. Assessing concentration–response relationships between contaminants and wildlife supports risk characterization and the management of contaminants in different environmental matrices xii. (aggregation/single criterion)
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Likewise, the Human Health Risk Assessment (HHRA) toolbox continues to play a vital role in the decision-making process at contaminated sites. It includes hazard and exposure evaluations, as well as risk characterization, aimed at assessing potential health effects on exposed individuals. Several advances in HHRA methodologies, notably those addressing multiple contaminants and their interactions, provide clearer insights into potential health risks and remediation requirements xiii. (aggregation/single criterion)
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Moreover, similar to NEBA, a Comparative Risk Assessment (CRA) methodology supports the prioritization of contaminated sites and cleanup actions based on relative risks, thus informing decisions about which site investigations and remedial actions are most urgently needed xiv. (aggregation/single criterion)
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The Risk-Based Corrective Action (RBCA) Toolkit specified by ASTM and endorsed by the EPA provides a structured approach to evaluating environmental hazards and prioritizing remediation actions. Related are risk-based soil screening levels (SSLs) used to prioritize contaminated sites based on the known or suspected ecological and health risks xv. (aggregation/two-criteria, i.e. ecological and human health risk)
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The EPA relies on several environmental scoring and ranking systems. The best known include the Hazard Ranking System (HRS), Air Quality Index (AQI), and Environmental Quality Index (EQI). These semi-quantitative screening tools communicate the severity of contaminated site risks, inhalation risks, and county-by-county environmental quality conditions, respectively. The Smart Location Index (SLI) and the environmental impact rating system convey the EPA's evaluation of the environmental impacts associated with federally funded projects xvi. (aggregation/single criterion)
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Health Impact Assessment (HIA) applied to site cleanup remedies typically includes baseline health assessments and predictive chemical fate modeling. HIAs have been used to assess disparities related to environmental exposure and propose actions that mitigate potentially adverse health outcomes during site remediation xvii. (aggregation/single criterion)
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Similarly, cumulative risk assessment (CRA) evaluates the combined effects of various biological, chemical, and non-chemical stressors, emphasizing the importance of understanding complex site conditions and the cumulative health risks at contaminated sites xviii. (aggregation/single criterion)
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Most site assessment tools include a Geographic Information System (GIS), which has become essential in environmental assessments. Spatial Analysis and Decision Assistance (SADA), for example, was developed by the Office of Solid Waste and Emergency Response. GIS visualization and spatial analysis of data support the identification of contaminated areas and geographical disparities in chemical exposures and effects, facilitating targeted interventions to mitigate contaminant risks xix. (aggregation/multiple criteria)
Engaging With Communities
If the EPA recognizes the functions and roles that different EDSTs serve in the decision-making process, i.e., aggregation or evaluation, the agency can reassure communities that taking action quickly at contaminated sites does not compromise public safety and well-being.
And yet, experience teaches that engaging with community leaders and advisory boards significantly influences site cleanup strategies, regardless of the choice of decision support tools. Communities deserve a voice in the environmental decision-making process. MCDA is a particularly valuable EDST tool for incorporating the voice of the community into the analysis. Presumably, quick action does not mean the EPA will abandon its approach to community participation. Maintaining transparency and accountability in selecting remediation actions while aligning closely with community needs and values contributes to achieving favorable decisions at contaminated sites and paving the way for swift action.
- https://doi.org/10.1002/2013WR014718; https://www.epa.gov/superfund/superfund-remedial-investigationfeasibility-study-site-characterization.
- https://doi.org/10.1007/s00267-004-0089-7.
- https://doi.org/10.1002/ieam.5630020111; https://semspub.epa.gov/work/05/209897.pdf.
- https://www.epa.gov/superfund/natural-resource-damages-assessments.
- https://serdp-estcp.mil/projects/details/c57ce24a-8677-4282-951f-63630a280e36/USA.gov.
- https://www.epa.gov/sites/default/files/2018-10/documents/acp_handbook_10-18-2018.pdf.; https://www.usace.army.mil/Missions/Environmental/FUSRAP/
- https://www.epa.gov/superfund/superfund-green-remediation; https://edit.doi.gov/sites/default/files/uploads/doi-edl-handbook-v4.0-2020_2.pdf.
- https://doi.org/10.1515/9783110765861; https://doi.org/10.1002/rem.21589.
- https://cfpub.epa.gov/si/si_public_record_report.cfm?LAB=NRMRL&dirEntryID=190505; https://archive.epa.gov/region5/superfund/fields/web/html/index.html.
- https://19january2021snapshot.epa.gov/ejscreen_.html; https://pedp-ejscreen.azurewebsites.net/; https://oehha.ca.gov/calenviroscreen.
- https://www.cdc.gov/environmental-health-tracking/about/index.html
- https://www.epa.gov/risk/ecorisk-portal.
- https://onlinelibrary.wiley.com/doi/book/10.1002/9781119742975.
- https://cfpub.epa.gov/ncea/risk/recordisplay.cfm?deid=12465
- https://store.astm.org/e2081-22.html; https://www.epa.gov/superfund/superfund-soil-screening-guidance.
- https://www.epa.gov/smartgrowth/smart-location-mapping#calculator; https://www.epa.gov/superfund/hazard-ranking-system-hrs; https://www.epa.gov/air-quality; https://www.epa.gov/healthresearch/environmental-quality-index-eqi.
- https://www.epa.gov/healthresearch/health-impact-assessments.
- https://www.epa.gov/risk/guidelines-cumulative-risk-assessment-planning-and-problem-formulation.
- https://www.epa.gov/geospatial; https://www.clu-in.org/conf/tio/sada/.
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