Closure of a contaminated site on the basis of a site-specific risk assessment demonstrating that residual contamination, with engineered or institutional controls, poses an acceptable risk to identified human and ecological receptors. The contaminant remains; the exposure pathways are demonstrated incomplete.
Risk-based closure is the regulatory alternative to meeting generic numerical cleanup criteria. The proponent demonstrates, with site-specific exposure data and modelling, that the residual contamination cannot reach receptors at concentrations exceeding acceptable risk. Engineered controls (caps, sub-slab depressurization, vapour barriers) and institutional controls (deed restrictions, land-use covenants) are commonly part of the closure package.
Risk-based closure trades off lower remediation cost against long-term land-use restrictions, institutional control obligations, and the residual liability of contamination remaining on site. It is the dominant closure path at industrial brownfields, complex DNAPL sites, and many federal contaminated sites where full source removal is infeasible. Where total cost-of-ownership including liability is the metric, permanent destruction can outperform risk-based closure even at higher direct remediation cost.
Also known as: risk-based closure, RBC.
A regulatory designation for the most effective and advanced stage of development of activities and operating methods. Regulators use BAT to set minimum performance standards for pollution control and contaminated-site remediation, anchored in technical and economic feasibility rather than vendor preference.
The U.S. federal law passed in 1980 that establishes liability, cleanup standards, and the Superfund program for sites contaminated with hazardous substances. The foundational statute for U.S. environmental remediation and the basis for the 2024 designation of PFOA and PFOS as hazardous substances.
A 2001 international treaty in force since 2004 that requires signatory countries to eliminate or restrict the production, use, and release of designated Persistent Organic Pollutants, including PCBs, dioxins, furans, and a growing list of PFAS compounds.
An independent third-party verification process for environmental technology performance, originally administered by the U.S. EPA and now operated by national and international programs in Canada, the European Union, and Asia. ETV documents what a technology actually achieves under defined conditions, separate from vendor marketing claims.