Electrics and gas
The oil-tank bund is full of rainwater so the tank base could not be seen. What containment has that water not demonstrated?
The water has not demonstrated that the bund would contain a leak of oil. The bund is already full of rainwater, so any spare capacity is hidden and the tank base could not be seen. The survey has recorded a bund full of water and a base out of sight. It has not emptied the bund, not inspected the base, and not tested whether the wall of the bund would hold oil. A bund that is full of rain is not showing you containment. It is showing you water.
Last reviewed 24 October 2026. Written for buyers in England and Wales unless this answer says otherwise. No named surveyor has signed this page. It is general guidance, not a report on your house, and not legal advice.
What is the fuller explanation?
A bund is a catch space around a tank. It only contains a leak if it is intact and if it is not already occupied. Rainwater to the brim means you cannot see the floor, the tank's feet or a split in the steel, and you cannot see room for oil. The survey did not pump the water out. It will not guess that the base is sound underneath, and it will not guess that the bund wall is tight.
Ask the seller, through the solicitor, for the tank's service record, and say that the bund was full so the base was hidden. A competent person can empty and inspect the bund. That is not a job the home survey did. Do not tell an insurer the containment was proved. The report shows the opposite limit: water in the way, base unseen, oil containment not shown.
What should you ask your surveyor?
- Was the bund full of rainwater when you saw it?
- Did that water stop you seeing the tank base?
- Have you left oil containment undemonstrated?
What are the typical next steps?
- Treat the full bund as a failed view, not as proved containment.
- Do not tell an insurer the base was inspected.
- Ask for the bund to be emptied and the base seen.
Costs vary with the building and with who you instruct. Where this page does not cite a published figure, ask the surveyor, a relevant specialist, or your solicitor for a written quote. Do not treat a forum average as the price.
Also asked about this
If the water is clear, has the bund been shown to be watertight?
Clear water is only clear water. It does not prove the bund would hold oil, and it hid the tank base. The survey has not tested the walls or the floor. Rain collected in a bund can arrive through an open top. It is not a containment test.
Does a new-looking tank make the hidden base acceptable?
No. A new-looking tank is the part above the water. The base was not seen, and containment of oil was not demonstrated. Paint or a recent jacket does not describe steel that sits in a flooded bund. The survey stopped at the water line.