In constructing bunds, it is important to consider that the bund needs to be subjected to a regular water retention test to ensure that there are no leaks or liquid going out of the containment area.
After all, the bunding is considered as the secondary containment vessel to protect against the consequences of failure of the primary containment vessel.
Key factors in construction of a bund are the following:
- The total volume of the containment vessel. Note that the capacity of the bunding should be at least 110% of the total volume of the containment vessel.
- Bund floor area. Because of the constrictions of the materials being contained it is generally required to have a smaller floor area where possible.
- Height of the bunding. Per regulation, should be at a maximum of 1.5 meters. This is to give allowance for fire fighting, ease of access, or natural ventilation.
- space in between the bund and the containment vessel. Should be at a minimum of 750 millimeters to allow ease of access.
- In case of a smaller floor area, a remote containment is put in place wherein a pipe or drainage leads from the containment area to the remote containment area.