A bund or secondary containment is a structure that is designed to contain leaks or spills from a tank or vessel – the primary containment. A bund lining is surface treatment designed to either protect the bund structure or improve the fluid tightness of the bund.
Why do bunds need lining?
Not all bunds need to be lined. Typically a bund will be lined if an aggressive chemical is to be stored in the bund that would attack the structure. A typical example would be a concrete bund that is containing a tank that stores a strong acid such as Hydrochloric acid. In the event of the tank leaking or rupturing the acid would quickly attack the concrete, compromising the ability of the bund to effectively contain the spill.
Another common reason for lining a bund would be that during periodic testing and inspection defects in the structure have been identified – typically cracking or fluid egress. By making repairs and applying a suitable lining the bund can be made compliant again and remove the risk of environmental damage from occurring in the evet of a leak or a spill.