Why do I need a Bunded Oil Tank?
Trailer Engineering | 18/03/2026
In many situations in the UK, a bunded oil tank is either legally required or strongly recommended.
- Abiding laws and regulations
- Reducing environmental risks
- Deterring fuel theft
- Protecting fuel quality
A bunded tank provides an additional layer of protection around stored fuel. Even when regulations do not explicitly require bunding, many engineers, installers and regulators consider it the safest and most responsible storage option.
Looking for a Bunded Oil Tank?
Trailer Engineering has over 50 years of experience in delivering fuel tank solutions, both off-the-shelf and bespoke to ensure our customers receive the most suited solution for their industry.
Reach out to our dedicated team for more information.
What Does “Bunded” Mean?
A bunded oil tank is often described as a “tank within a tank”. The inner container holds the fuel, while an outer protective shell surrounds it and acts as secondary containment.
If the inner tank were ever to fail due to damage, corrosion, or accidental impact, the outer bund captures the fuel and prevents it from leaking into the surrounding ground. This design significantly reduces the risk of environmental contamination and fuel loss.
Reasons why you need a Bunded Fuel Tank
Environmental Reasons to Use a Bunded Tank
Oil spills can cause serious environmental damage. Even relatively small leaks can contaminate soil, drains, and nearby waterways.
Once oil enters the ground or drainage system, it can spread quickly and become extremely expensive to clean up. Environmental remediation may involve removing contaminated soil, specialist waste disposal, and long-term monitoring of the affected area.
Using a bunded oil tank helps reduce this risk by ensuring that any leak is contained within the outer bund rather than escaping into the environment. Pollution prevention is one of the main reasons regulators encourage bunded fuel storage across many industries.
Practical Reasons to have a Bunded Oil Tank
Even where bunded tanks are not legally required, many organisations choose them because of the practical advantages they provide.
Increased Safety
Uncontrolled fuel leaks can create hazards in working environments, particularly on busy sites where vehicles and machinery operate. Bunded tanks provide an additional protective barrier that contains spills before they spread, helping reduce the risk of accidents, environmental damage, or disruption to nearby infrastructure.
Trailer Engineering understands the importance of fuel storage safety, which is why our fuel bowsers come with a 10-year U.N. certification as standard.
Protection from Rainwater
Fuel storage systems installed outdoors must withstand exposure to weather conditions. A properly designed bunded tank helps prevent rainwater or debris from entering the primary fuel container, which helps maintain fuel quality and reduces the likelihood of contamination affecting machinery or generators.
Financial Reasons to have a Bunded Oil Tank
Increasing Longevity
The double-walled construction of a bunded tank offers greater resilience than a single-skin alternative.
The outer structure provides an additional layer of defence against accidental impact, corrosion, or external wear, which can extend the service life of the tank and reduce maintenance requirements over time.
Our customers have complimented the longevity and quality of our fuel storage tanks, making it a solution they continuously come back to.
Preventing Loss of Oil
Fuel represents a significant operational cost, so even small leaks can become expensive over time. With a bunded tank, any oil escaping from the inner container is captured by the outer bund rather than being lost to the ground.
This containment helps protect fuel supplies and reduces the financial impact of undetected leaks.
When a Bunded Tank Is the Safer Choice
In many situations, bunded tanks are recommended even when regulations do not strictly require them.
Examples include:
- Farms and agricultural storage areas
- Construction sites storing diesel for machinery
- Commercial yards and depots
- Sites located near drains, rivers, or environmentally sensitive areas
These environments typically involve higher fuel volumes and greater risk of accidental damage or leaks, making secondary containment particularly valuable.
Trailer Engineering's Work with Bunded Fuel Tanks
On active construction sites, safe fuel storage is essential. Equipment such as excavators, generators, and site vehicles often rely on diesel supplies stored on site.
Trailer Engineering has supplied bunded fuel bowsers designed specifically for demanding construction environments. These units provide robust containment, secure storage, and easier transport of fuel around site locations.
By using bunded fuel tanks and bowsers, construction teams can reduce the risk of spills, improve compliance with environmental guidelines, and ensure fuel remains protected throughout the project lifecycle.
Choosing the Right Bunded Tank
Selecting the correct oil storage system depends on several factors including required fuel capacity, site conditions, regulatory requirements, and expected usage patterns.
Many organisations choose engineered bunded tanks because they provide greater reliability, compliance assurance, and long-term durability compared with basic single-skin designs.
Trailer Engineering manufactures off-the-shelf and custom-built bunded fuel tanks and bowsers in the UK, designed to meet demanding operational environments across construction, agriculture, and commercial sectors.
To explore available options, see the Trailer Engineering fuel bowsers range.
Speak to Trailer Engineering About Bunded Fuel Storage
If you are unsure whether a bunded oil tank is required for your property or site, speaking with an experienced engineering team can help clarify the safest and most compliant option.
Trailer Engineering designs and manufactures bunded tanks built for reliability, safety, and environmental protection. Contact the team to discuss your fuel storage requirements or request advice on selecting the right solution for your application.
Check out our complete, detailed guide to uncover the benefits of using our water bowsers by clicking here or by getting in touch with a member of our friendly team today at +44(0)1384 564765 , by emailing [email protected] or by using our quick and simple contact form. We look forward to hearing from you.
Need A Water Storage Solution for Your Construction Project? Get In Touch:
Frequently Asked Questions About Bunded Oil Tanks
A single-skin tank has only one wall. If the tank fails, fuel can escape directly into the surrounding environment. A bunded tank has a second outer wall designed to capture leaks from the inner container.