Tiered approach to sustainability analysis in sediment remediation decision making

Abstract

AbstractAll active remediation results in both desirable and undesirable environmental, economic, and social impacts. Balancing such impacts through sustainability assessment poses normative questions—not just objective and science‐based, but those rooted in societal values, requiring engagement and a careful consideration of diverse stakeholders' priorities. Regardless of the site complexity, these priorities should be integrated into assessment approaches, a necessary evolution of sustainability for sediment remediation projects. We explore how analyses of environmental, social, and economic sustainability can be tailored for different tiers of assessment for sediment remediation projects, ranging from simple to complex. Tiers (1, 2, and 3) can be used to categorize evaluations of sediment projects across a range of complexity. Site size and complexity, availability of data, time, resources, expertise, and the level of engagement of various stakeholder groups may dictate the appropriate complexity, tools, and metrics to be used in a sustainability assessment. Assessment approaches in each pillar of sustainability (environmental, economic, and social), listed in order of increasing complexity (i.e., Tier 1 to 3) include:Environmental: (1) best management practices; (2) footprint assessment; and (3) life cycle assessment;Economic: (1) incremental cost‐effectiveness analysis; (2) addition of economic impact analysis with a detailed economic impact model (IMPLAN);and (3) substitution of a more comprehensive and complex economic impact model (Regional Economic Models, Inc.); and,Social: (1) qualitative inference of stakeholder values; (2) quantification of metrics in a multicriteria analysis; and (3) targeted engagement with elicited values from a broad group of stakeholders.Tools at all assessment tiers add value for a project; they can effectively provide context and trade‐offs for stakeholders and decision‐makers. A Tier 1 assessment requires fewer resources and less time than more complex assessments; however, it carries greater uncertainty and may not provide the detail or completeness needed to evaluate the tradeoffs between alternatives, across pillars. The range of options available for Tier 2 medium‐complexity analyses span qualitative and quantitative metrics; aggregation methods are tailored to the governing regulatory framework or stakeholder values; and a variety of tools for measuring environmental, social, and economic impacts. Tier 3 assessments, like those completed for the Portland Harbor Superfund Site, provide the most complex and complete assessments, including a detailed means of obtaining stakeholder values to aggregate the metrics. Tier 3 assessments require greater time and budget but may highlight important differences between remedial alternatives that could be obscured at lower tiers.