Can You Store Diesel in a Bunded Oil Tank? A Practical Guide for UK Users

If you run a farm, manage a construction site, or rely on generators off-grid, safe diesel storage is essential. One of the most common questions we hear is: can you store diesel in a bunded oil tank?

In most cases, the answer is yes — a bunded tank is one of the safest and most compliant ways to store diesel in the UK. However, there are important considerations around tank design, regulations, and maintenance that you need to understand before filling up.

This guide explains how diesel behaves in storage, what the rules say, and how to keep your fuel in good condition.

Can You Store Diesel in a Bunded Oil Tank?

A bunded oil tank has two layers: an inner tank that holds the fuel and an outer layer (the bund) that catches leaks or spills. While these tanks are often associated with heating oil, many are also designed for diesel storage, provided they are correctly specified.

Diesel and heating oil are both middle-distillate fuels derived from crude oil, but diesel is often used in engines and may contain performance additives. Because of this, diesel storage systems typically require:

• Cleaner tanks and fittings

• Proper filtration

• Protection against water contamination

For a deeper technical overview of diesel storage requirements, this expert guide from Tuffa Tanks explains key considerations around safe and compliant diesel storage:
https://www.tuffa.co.uk/an-expert-guide-to-diesel-storage/

Legal Requirements for Diesel Storage in the UK

When storing diesel, environmental protection is the main concern. A spill can contaminate soil, drains, and watercourses, which is why bunded diesel tanks are widely recommended and often required.

Key points to consider:

Secondary containment
In many commercial and agricultural situations, a bunded tank is expected because the outer bund can hold at least 110 percent of the inner tank’s capacity. This significantly reduces the risk of pollution.

Location and installation rules
Tanks must be positioned safely away from drains, watercourses, and buildings where possible. A stable base and secure fittings are also essential.

Spill prevention
Using proper fill points, overfill protection, and regular inspections helps you meet environmental responsibilities and avoid costly clean-ups.

While specific requirements can vary depending on capacity and use, choosing a bunded diesel storage tank is one of the simplest ways to stay aligned with UK environmental expectations.

Practical Tips for Storing Diesel Safely

Even with the right tank, good fuel management is essential for long-term diesel fuel storage.

1. Prevent Water Contamination

Condensation can form inside any fuel tank, especially with temperature changes. Water in diesel can lead to microbial growth and clogged filters.

• Keep the tank as full as practical to reduce air space

• Use a water trap or separator if dispensing fuel

• Check regularly for signs of water at the bottom of the tank

2. Maintain Clean Fuel

Diesel is often used in sensitive machinery, so contamination can cause expensive damage.

• Use proper filters on pumps and dispensing systems

• Keep fill points clean and sealed

• Avoid mixing old and new fuel without checking condition

3. Inspect the Tank Regularly

Routine checks are a key part of diesel tank maintenance.

• Look for cracks, bulges, or damage to the outer bund

• Check pipework, valves, and hoses for leaks

• Ensure vents and caps are secure and unobstructed

A bunded tank gives you an extra layer of protection, but it still needs regular attention.

Diesel Storage for Different Users

Farms and Agricultural Sites

Agricultural machinery depends on reliable fuel. A bunded diesel tank helps protect land and watercourses while keeping you supplied during busy seasons.

Construction and Plant Hire

Onsite fuel storage is common, but so is environmental risk. Bunded tanks reduce the chance of spills affecting the surrounding area and help meet site safety expectations.

Off-Grid Homes and Businesses

If you use diesel for generators or backup power, safe storage ensures your fuel stays usable and your property stays protected.

Choosing the Right Tank

Not all tanks are suitable for every fuel or application. It’s important to choose a model clearly rated for diesel storage and sized appropriately for your needs.

You can browse a wide range of suitable tanks here:
https://www.oiltanksplus.co.uk/oil-tank-range/

If you need help selecting the right option or checking compatibility, the team at Oil Tanks Plus can provide guidance based on your use and location:
https://www.oiltanksplus.co.uk/

Final Thoughts

So, can you store diesel in a bunded oil tank? In most cases, yes — and it is often the safest and most responsible option. A properly specified bunded diesel tank helps prevent pollution, supports compliance, and protects your fuel from contamination.

By combining the right tank with good maintenance and fuel management, you can store diesel confidently and keep your equipment running smoothly.