is a casing of either concrete
or earth which surrounds an oil storage tank. The height of the bundwall and the surface area within it are designed so that the internal volume is 110% of the volume of liquid contained in the largest storage tank. These bundwalls must be strong enough to contain the liquid, upon tank rupture, without collapsing.
For the removal of liquids from within the bundwall, i.e. rainfall or leaked oil, a system of piping must be fitted during the bundwalls creation. This liquid can then be removed when required and treated in an appropriate process. Drains are prohibited from being located within the bundwall unless they are connected to treatment processes.