A relation-analysis-based approach for assessing risks of petroleum-contaminated sites in Western Canada

Effective reflection of and coping with uncertainties are essential for generating reliable risk assessment outcomes. In this study, an integrated risk assessment approach was proposed for assessing environmental risks associated with contamination of multicomponent petroleum hydrocarbons. The approach consists of (a) predicting contaminant flow and transport through a multiphase multi-component numerical modelling system; (b) using interval-anlaysis approach to analyze effects of uncertainties associated with subsurface conditions; and (c) applying fuzzy relation analysis to quantify the general risks based on the interval-analysis results. The application of the proposed approach to a petroleum-contaminated site in western Canada indicated that system uncertainties would have significant impact on the risk assessment results. Implementation of risk assessment under more deterministic conditions generates clearer risk assessment outcomes, but leads to missing of more valuable information; conversely, risk assessment under more uncertain circumstances offers more comprehensive information, but leads to higher vagueness of risk descriptions. Application of the proposed approach in risk assessment of groundwater contamination represents a new contribution to the area of petroleum waste management under uncertainty. It is not only useful for evaluating risks of a system containing multiple factors with complicated interrelationships, but also advantageous in situations when probabilistic information is unavailable for performing a conventional stochastic risk assessment. © 2012 by Nova Science Publishers, Inc. All rights reserved.