Bunding is a legal requirement in many countries, particularly around tanks, storage vessels and other plants that contain liquids which may be dangerous or hazardous to the environment. Particular examples which receive specific attention in the UK, the rest of Europe and the USA are oil and fuel storage tanks and transformers at electricity sub-stations which are filled with oil for cooling and insulation purposes. In the UK commercial installations exceeding 200 litres and domestic installations exceeding 2500 litres require a bunded tank to comply with Environment Agency ‘control of pollution regulations’.
It is reasonably easy to construct a “water-tight” bund around the base of a tank or vessel. A concrete base and a sealed wall of masonry, brickwork, concrete or even prefabricated steel provides the holding capacity