When it comes to chemical and oil storage, a concrete bund wall is a key component. These special retaining walls provide a barrier around certain storage areas for substances which could pollute the environment – and they have an important job to do. They stop the held material escaping from the tank, which is why they’re required by many site permits like IPPC, IED and Waste Licences.

The walls of a bunded area must be of earth, steel, concrete or solid masonry designed to be liquid tight and capable of withstanding a full hydrostatic head. Where earthen walls are used they must have a slope in cross-section of not less than 1 in 1.5 and must have a flat section not less than 1.5 m wide at the top of the wall.

Advantages of Concrete Bund Walls: Protection and Containment

Codes vary with respect to their recommendations on the height of bund walls. Low wall heights (usually 1-1.5 m) facilitate firefighting but are poor defence against spigot flow or the tidal wave effect of catastrophic tank failure. In general, the higher the wall, the greater the defence.

As with all safety-critical structures, it’s vital that the bund walls are regularly checked and tested. This is typically done with a visual assessment by a competent person. This involves examining the inner and outer walls of the bund, as well as where pipes penetrate them. It’s also recommended that a low-level hydrostatic test is carried out, which involves filling the bund with water to see whether it can hold its contents in the event of a spill. This is an important service which Environmental Efficiency can carry out for you, using water tankers that we can hire and our own team of Chartered Engineers with Confined Space Entry certs.