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UBC Theses and Dissertations

Decision-making for acceptable risk in contaminated site problems in British Columbia Thomas, Deanna


Contaminated sites are a common problem across municipalities in the Greater Vancouver Regional District. These problems are complicated and multi-dimensional, and raise fundamental concerns about the risks to human and environmental health. This thesis shows however, that there are no easy answers to how much risk is "acceptable", and no one right way to decide. How the acceptable risk problem is structured is important, because fact and value issues, a source of controversy and dispute, are variously interpreted depending on how the problem is cast. The literature generically categorizes acceptable risk as either a technical, social or decision problem, and each of these have implications for the types of decision-making approaches and solutions that are considered appropriate in resolving acceptable risk. This thesis investigated how acceptable risk in contaminated site problems is handled in British Columbia by reviewing the provincial decision-making framework, and by surveying municipalities in the Greater Vancouver Regional District for their views on contaminated site problems and acceptable risk decision-making. The underlying goal of the thesis is to question the use of the current approach, the Pacific Place site criteria, as a model for acceptable risk decision-making in the province, and to explore the implications for urban communities. The Ministry of Environment is the central authority for contaminated sites in British Columbia and has generally taken a scientific and technical approach to the problem. Although the municipal survey suggests that the Pacific Place site criteria has a broad base of support in the GVRD, the technical emphasis has implications for urban communities. The approach is expert-oriented and largely excludes local and public involvement in the acceptable risk debate. The major concern is that important social value issues have been neglected, relative to the engineering and technical aspects of the problem. The research also finds however, that the majority of individuals in the municipal survey are willing to explore other methods of determining acceptable risk, and support in principle, local government and public involvement in deciding what these methods should be. This thesis suggests that British Columbia can benefit from a more comprehensive view of acceptable risk in contaminated site problems. Resource limitations at the provincial and local level, and the high stakes in contaminated site problems for urban communities point to the growing importance of incorporating a broad range of value issues and understanding the trade-offs in acceptable risk decisions. The Ministry of Environment can improve the current decision-making approach by: incorporating structured value assessments that elicit stakeholder values and address trade-offs; involving a wider range of stakeholders in standard setting and risk assessment, including the forthcoming review of the Pacific Place site criteria; creating forums to explore other decision-making approaches; and by encouraging private sector involvement in risk assessment and risk management. The province can also encourage and support community-based institutional networks, both at the municipal and regional level.

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