What is a Bunded Fuel Tank?

If your home relies on domestic heating oil or your business has commercial fuel tanks, you may be wondering what a bunded oil tank is and whether or not you need one. In this post, we're going to explain bunded oil tank regulations and the benefits they offer our heating oil users.

What is a Bunded Oil Tank?

A bunded oil fuel tank is basically a tank within a tank. It allows for 100% containment in the main tank, plus an additional 10% in the bund, totalling a 110% volume. This means that, in the eventuality of a leak, 100% of the fuel can be held by the tank's second layer and the fuel would need to break through both layers of the tank to impact the surrounding environment.

With single layer tanks, if the skin of the tank is punctured, there is no safe or effective way to stop an oil spillage. In turn, this can cause major damage to the surrounding land and waterways. Justifiably, these spillages can carry large fines.

Bunded oil tank regulations were introduced to enhance safety and reduce the likelihood of spillages and consequential environmental damage.

Do I need a Bunded Oil Tank?

It is not always illegal to have a single-skin tank, however if you are installing a new heating oil tank, whether for domestic, commercial or agricultural purposes, it must be a bunded oil tank.

Likewise, if you are storing more than 3,500 litres of oil in England, you must have a bunded oil tank. Plus, if the vents of your tank cannot be seen by the heating oil delivery person from the fill point, your tank must be bunded.

Bunded fuel tank regulations also cover the location of your tank, predominantly to prevent the risk of oil spills into waterways. Your tank must have a bund if it is:

  • Within 10 metres of water, including (but not limited to) streams, rivers, lakes, ponds and canals.
  • Within 50 metres of drinking water sources, including (but not limited to) wells, boreholes and springs.
  • Located where an oil spill would run into an open drain or manhole cover.
  • Located over hard ground, whereby the oil could run over it until reaching any water source.

If you are looking to store fuel for your premises as safely as possible, a bunded oil tank is advised.

Are the Bunded Oil Tank Regulations different in England, Wales and Scotland?

Yes, each country has different bunded oil tank regulations. The most significant difference between the three nations is the minimum volume of oil that your tank can contain before a bund is required by law. In England, you must have a bunded tank if you are storing over 3,500 litres of oil. However, in Scotland the minimum volume is 2,500 litres and, in Wales, it is just 200 litres.

What are the Benefits of a Bunded Fuel Tank?

1. Prevents Spills.
Based on the design of the bunded fuel tank, if punctured, the inner membrane remains and continues to contain fuel. This complies with the 2001 Control of Pollution Regulation, stipulating that tanks must provide a secondary containment capability. Plus, without proper tank maintenance, corrosion can occur within the tank, which would more easily cause a leak in a single-skin tank.

2. Enhanced Health and Safety.
An oil spill can not only cause damage to the environment, but it can pose a health and safety risk to people as well. Oil can be hazardous to touch, and the fumes from an oil spill can be unsafe. Plus, if an oil leak was to occur, it could mix with water and travel to our waterways.

3. Deters Fuel Theft.
Fuel theft is a real threat that you should be aware of, especially with soaring and volatile heating oil prices. Bunded fuel tanks are generally more robust than single-skin tanks and, with two layers to penetrate, it's naturally more difficult for thieves to access and drain your oil. If a thief does attempt to drain your oil, it will take them more time, giving you a better chance to catch them.

4. Better for the Environment.
The 'Tank with a Tank' design function makes the bunded oil tank the most environmentally-friendly solution for storing fuel. The tank's secondary layer reduces the likelihood of a spillage as a leak would be contained within it, therefore protecting the soil, vegetation, animals and waterways from chemicals in the oil. This is one of the primary reasons why bunded fuel tank regulations were introduced.

5. Plentiful Choice of Tank.
There is plenty of variation when it comes to bunded oil tanks so you can easily find one that suits your requirements. For example, at Rix, our bunded fuel tanks range from a 350 litre capacity up to 8050 litres. Plus, these tanks are available in various designs and materials, including steel and premium grade, oil-resistant polyethylene.

6. Improved Cost-Savings.
Although an initial upfront investment for your fuel storage, a bunded oil tank means your fuel is less likely to spill and cause damage, helping you to avoid fines handed out by authorities such as the Environmental Agency. Plus, bunded fuel tanks are typically more durable than single-skin tanks, so they should have a longer lifespan. In some cases, a bunded tank can even help you to secure a lower insurance rate thanks to their enhanced security, safety and reliability.

7. Reduced Waste.
Unfortunately, oil leaks can happen for a number of reasons, including damage to tank equipment or wear-and-tear. Not only can this be hazardous, but it is also a waste of resource and your money. Fuel is a cost to your household or business, especially in this climate, but with a bunded tank a leak is unlikely to result in lost fuel.

Top Tip: According to UK guidelines, you should have your heating oil tank serviced at least once a year by an OFTEC engineer. They will undertake a tank health check to help you spot any existing or brewing issues with your tank.

8. Peace of Mind.

By storing your oil in a bunded fuel tank, you can enjoy added peace of mind with a safer and more secure type of tank. It is also an insurance-policy if you like, in your premises and its surroundings as you take the measures to avoid any spillages.

We hope you're now feeling confident with what a bunded oil tank is and whether or not you need one based on bunded fuel tank regulations. To learn more about the types of oil tank, please read our dedicated guide. Alternatively, if you have any questions about your heating oil storage options, please don't hesitate to contact our friendly team.