Assuming cleanliness, an above ground tank will need to used with a mindset toward heat/ evaporation and many sites require a bund wall capable of containment. Some sites may require protection from collision. I've only seen 500 gallon tanks used as temporary means of fuel delivery at fly-ins but many on private property. Your fuel agent will either deliver or not according to his interpretation of his responsibilities and duty of care. He issues the release note after all. If you purchased the quantity in 200 litre drums, where you put it is your business. I wouldn't ask CAsA.