There are a number of low probability but high impact events that could occur. The severity of impact will depend on site-specific factors, such as the proximity of local communities or valuable water resources, and the controls in place. Here are some examples:
• a mine collapse;
• equipment failures or releases of radioactive and toxic elements due to human error or technological failure;
• extreme weather events, with or without flooding, that could affect the engineering controls leading to a release into the environment;
• a release of a large quantity of fuel or chemical reagent stored on-site; and
• a fire or an explosion related to the on-site propane.