Bunded fuel tanks — including static units and towable bowsers — are a crucial part of any site that stores diesel, HVO or petrol. But without proper maintenance, even a bunded tank can become a risk.
This guide from Ace Plant, the home of the Bundie Bowser, outlines how to inspect and maintain your bunded fuel tank to stay safe, compliant, and operational!
Why bunded fuel tank maintenance matters
Bunded tanks are designed with a built-in secondary containment area to catch spills or leaks. However, if the tank or bund is damaged, blocked or filled with rainwater, this vital safety feature can fail.
Routine maintenance ensures your tank is:
It also protects your business from unexpected costs, fines or environmental damage.
You can read more on your legal obligations in our Fuel Storage Regulations Guide for UK Businesses.
Step-by-step bunded tank maintenance checklist
Here are our tips for thorough bunded fuel tank maintenance.
1. Carry out regular inspections
Visual inspections should be carried out weekly and after any major weather event. During these checks, look for signs of corrosion, cracks, fuel staining, or any physical damage to the tank or bund.
Check that:
- All hatches, lids, locks and caps are secure
- Pipework and hoses are tight and undamaged
- The bund is free from litter, debris or standing water
If water is found inside the bund, it should be removed as it may reduce the containment capacity in an emergency.
2. Clean the interior periodically
Over time, sludge and water can build up inside the tank. This often results from condensation and can lead to microbial growth, blocked filters or injector damage.
Tank cleaning should be carried out by a qualified professional. The frequency depends on usage and fuel type, but a general rule is:
- High-use tanks with diesel or HVO: clean annually
- Low-use tanks: every 3–5 years
Avoid DIY cleaning as it can be hazardous and may invalidate warranties or damage the tank.
3. Maintain secure pipework and connections
Fuel lines and fittings must be checked regularly for leaks, degradation or wear. Loose pipework is a common cause of fuel loss and environmental incidents.
As part of your inspection routine:
- Visually check pipework for leaks, wear or looseness
- Ensure valves and gauges are within the bunded area
- Arrange an annual inspection by a competent technician
4. After heavy rainfall, inspect for water ingress
Rainwater inside the bund is not just a nuisance – it can severely limit the bund’s capacity to contain a spill. Bunds should hold at least 110% of the tank’s capacity, and water accumulation reduces this buffer.
After storms or prolonged rain:
- Check for water pooling in the bund
- Make sure no cracks, gaps or drains compromise containment
- Remove rainwater safely using appropriate methods
5. Record all inspections and servicing
Keeping accurate maintenance logs is part of fuel storage compliance and good site management. This includes:
- Weekly inspection notes
- Professional servicing records
- Cleaning dates and technician details
Clear documentation provides evidence of compliance under COSHH, DSEAR, and pollution prevention regulations.
Best practice: prevention, not reaction
To protect your tank and site, apply preventative measures such as:
- Training staff on proper filling and inspection procedures
- Securing tanks from unauthorised access or vandalism
- Monitoring fuel levels to detect unusual drops or leaks
If you're hiring fuel storage equipment, regular checks still apply. All Bunded Fuel Storage units from Ace Plant are maintained to the highest standards, but users must still follow good practice on-site.
Explore our full hire range:
Keep your site safe and your tanks compliant
A well-maintained bunded fuel tank helps avoid leaks, reduces environmental impact and ensures compliance with UK storage regulations.
Whether you're using a static bunded bowser, towable unit or truck-mounted solution, regular inspections and professional servicing are essential.
Need a compliant, maintained fuel tank for your next project? Hire bunded fuel storage from Ace Plant – from 1000L to 18,000L, delivered nationwide.
Frequently asked questions about bunded fuel tank maintenance
How often should I inspect a bunded fuel tank?
You should visually inspect your bunded fuel tank at least once a week. Look for signs of corrosion, cracks, leaks, or water build-up in the bund. After heavy rainfall or freezing conditions, additional checks are recommended.
Is bunded fuel tank maintenance a legal requirement in the UK?
While there is no specific law requiring maintenance, UK regulations such as the Control of Pollution (Oil Storage) (England) Regulations 2001, COSHH, and DSEAR require that fuel storage systems are safe and properly maintained. Regular inspections, record keeping and servicing are essential for compliance.
What should I do if water collects in the bund?
Rainwater must be removed from the bund without discharging fuel-contaminated liquid into the environment. Use an appropriate method such as a vacuum pump and ensure proper disposal. Leaving water in the bund reduces its capacity to contain a spill.
How often should bunded fuel tanks be cleaned?
Cleaning frequency depends on fuel type and usage. High-use tanks or tanks storing biofuels or HVO should be cleaned annually. Lower-use tanks may be cleaned every 2–3 years. Always hire a qualified professional to carry out internal cleaning.
Can I hire bunded fuel storage tanks from Ace Plant?
Yes. Ace Plant offers a wide range of Bundie Bowsers and static bunded fuel tanks for hire, ranging from 1,000L to 18,000L. All units meet 110% bunding requirements and come with optional features like petrol-driven or electric pumps.
Explore our bunded fuel storage range here .
Where can I learn more about UK fuel storage rules?
Ace Plant has a dedicated guide explaining the latest UK fuel storage regulations, bunding requirements, and compliance advice. Read our fuel storage regulations guide for UK businesses .