The legislation typically reads as follows: the bund must have sufficient capacity to contain 110% of the volume of the largest container; or 25% of the total volume stored on the bund, whichever is greater.
This means a 4 drum bund (sump capacity 230 litres) can be used to store up to 4 x 205 ltr drums (205 x 110% = 225.5 litres, 820 x 25% = 164.0 litres) or 46 x 20 litre drums (20 x 110% = 22.0 litres, 960 x 25% = 230 litres), but cannot be used to store a 1,000 ltr IBC (1000 x 110% = 1100.0 litres). If you would like to discuss your needs further, please contact us on +61 2 4827 0222, or email firstname.lastname@example.org.
However storage requirements do vary depending on the product being stored – typically, flammable liquids, corrosive substances, oxidising agents and organic peroxides must be stored in compliant dangerous goods safety cabinets rather than on bunds.
Please note this advice is general in nature, and is based on Australian legislation. If you are unsure please check with a Dangerous Goods consultant.