Bunding is a barrier that separates areas where dangerous spillages may occur, ensuring that dangerous liquids don't enter the general sewage system and minimising the risk of pollution. It is a part of a spill containment system, and the whole area the bunding surrounds is referred to as the "bund".
There are many regulations surrounding when you need a bund, what type of bunding you should use, and how your bund should be constructed. Download Green Stamp Plus' Bunding fact sheet here, or check out the EPA NSW website for more information. For advice regarding your workshop's bunding and how it can be improved, contact MTA NSW.