Lessons Learned Over Twenty Years of Experience in the Development and Application of Risk Assessment Process for Management of Contaminated sites

The primary objective of managing contaminated sites is to ensure the protection of human health and the environment under current and future conditions. Since the publication of the Risk Assessment Guidance for Superfund, RAGS (1989), the practice of human and ecological risk assessment as applied to the management of contaminated sites has evolved considerably in the US. What started as a purely regulatory requirement has become the primary decision making tool for the management of contaminated sites. This evolution has been helped by several landmark publications (i) USEPA's Soil Screening Guidance Document (1995), (ii) ASTM's Risk Based Corrective Action (RBCA) Standard (1995), (iii) USEPA's RAGS (Part D) Preliminary Remediation Goals (1994), (iv) USEPA's Draft Vapour Intrusion Guidance Document (2002), and (iv) state-specific RBCA programs developed and implemented by over 20 states in the US. Currently, several countries in Europe, Asia, and Latin America are in the process of developing customized risk based programs to manage contaminated and Brownfield sites. The US experience has significantly enhanced mankind's understanding of the behaviour of chemicals in the environment, their impact on human health and the environment, and sharpened the decision making process at contaminated sites. Communities and nations contemplating the development of customized programs to manage impacted sites can learn from the US experience and hopefully develop better and more efficient processes to manage and develop contaminated sites.