One example that you may be able to research is the configuration of the tailings storage at the Ranger Uranium Mine in Australia's Northern Territory. The choices they had were either to dig a pit for the tailings, or build a dam for the tailings. A pit would leak a certain amount of contaminants into the surrounding waterways in the Kakadu National Park, and be more susceptible to flooding, but be more resistant to a catastrophic event such as a tropical cyclone, as there is no wall for the high winds to destroy. A tailings dam would be resistant to flooding, and as the construction of a dam can include control over the materials used to line and seal the dam, it would also not continually release contaminants into the environment. However, the dam wall would be susceptible to catastrophic failure in the event of a tropical cyclone, releasing the entire contents of the tailings storage into the environment.
This situation highlights the wicked problem nature of environmental risk assessment. The choice was made in the end to build a dam, and the result of that choice could, at some point in time in the future, result in the escape of millions of tons of toxic and radioactive contaminants into an extremely sensitive waterway.