RBCA Toolkit: Comprehensive Risk-Based Modelling System for Soil and Groundwater Clean-Up

Abstract

The ASTM “Standard Provisional Guide to Risk-Based Corrective Action” [2] expands upon the earlier RBCA standard for petroleum releases to establish a comprehensive process for management of both human health and ecological risks associated with chemical releases to soil or groundwater. Modelling tools can prove helpful at various points of the RBCA site evaluation process, including exposure pathway screening, tiered evaluation of cleanup standards, remedy selection, and design of the compliance monitoring program. This paper provides practical guidelines for the use of modelling tools in the risk-based decision-making process and reviews the RBCA Tool Kit for Chemical Releases, a comprehensive modelling and risk characterisation software designed for completion of RBCA Tiers 1 and 2. Key topics include application of modelling tools to risk-based site evaluations; model selection guidelines; applicable analytical models for soil, groundwater, surface water, and air exposure pathways; and use of transient and probabilistic modelling methods.