The regulations for above-ground fuel storage on farms (greater than 4ha) require secondary containment where more than 2500L of petrol or diesel is stored in a tank, or if there is a risk a spill will endanger buildings or water bodies. Steel containment bunding on farm is compliant for petrol and diesel.
For other applications of fuel storage (not on a farm), secondary containment / bunds are required where more than 1000L of petrol or diesel fuel is stored. Requirements are dependent on the location and local certifier. For bunding (not on a farm), steel bunding is compliant for diesel, for petrol, use a concrete bund.
Your local authority should be able to advise of the requirements for bunding of single skin tanks. Mainline-manufactured containment bunds, for tanks up to and including 5000L, are manufactured from 2.5mm galvanized sheet.
Fuel Tank brochure
