ENVIRONMENTAL QUANTIFIED RISK ASSESSMENT - PROMISES AND PITFALLS

Within BP, over the last 10 to 15 years, Quantified Risk Assessment (Q RA) has been extensively used as a safety decision aiding tool. Just a s in safety, decisions on protecting the environment have often been t aken purely on the basis of perceived, rather than actual, risk. The m otivation for conducting Environmental Quantified Risk Assessment (EQR A) is that it offers a way forward by introducing some much needed obj ectivity into decision-making on environmental protection management. Quantification could also facilitate a more integrated approach to hea lth, safety and environmental issues. For example, measures which are taken for the purpose of reducing the risk to the environment, may at the same time increase the risk of humans. If risk to humans and the e nvironment could be expressed in a common 'currency', the decisions co uld be based on the optimization of risk to all parties. The Paper dev elops a framework for conducting EQRA studies, based on the well estab lished formula used in safety studies - comprising identification of t he hazardous events, quantification of event likelihood and consequenc es and making a decision on the acceptability or otherwise of the risk levels. Difficulties are highlighted - notably in determining the imp act of releases on whole ecosystems and in formulating some method whe reby the acceptability of environmental risk may be judged. The Paper concludes that initial effort should be focused on expanding QRA techn iques to areas of environmental risk which are better understood, e.g. the assessment of the impact of acute accidental releases - especiall y for those materials (such as persistent oils) where there is ample i nformation on their impact on the environment.