Oil Storage Tank Maintenance

Pollution incidents from faulty Oil tanks and fuel lines are on the increase. These leaks are usually caused by badly maintained tanks and fuel lines.

Leaked oil can be very difficult and expensive to clean up. Clean up costs can be extremely high, the sort of money that would buy a small home. In some circumstances, oil has soaked into the ground producing fumes and odours that have caused adjoining houses to be evacuated, leaving it impossible to live in the properties without major building works.

With a few simple and quick checks now, you could save tens of thousands in the future.


  • Look all over your oil tank for oil stains. If the stains aren’t around fittings then they are much more serious.
  • Check around your house, inside and out, behind cupboards and all over outbuildings for signs of staining, dead plants and subsidence. If oil pipes run underneath neighbours land or property, ask to have a quick inspection.
  • If the tank is near a river or stream, check for signs of life, oil staining on the water surface or thick brown froth
  • Check for rust, flaked paint and cracks. Check all fittings and pipe work.
  • On plastic tanks check for surface bleaching by the sun.
  • On plastic tanks check for warping and distortion
  • Supervise all oil deliveries and make sure that you do not order more oil than your tank can hold.
  • For metal tanks, ensure that they are regularly painted with suitable paint.
  • Do not paint plastic tanks
  • Regularly inspect your oil usage rate and keep a log. If your usage is high for the time of year, this can indicate a leak.
  • If your tank is filled on contract, especially whilst your our out, ensure you get a bill showing when and how much oil was added.
  • Ensure you know when and how regularly your oil deliveries are coming.
  • Keep the fill gauge clean and free from obstruction.
  • Make sure your tank is tamper-proof
  • Get your tank regularly inspected by a professional.

Most modern tanks are now bunded or double skinned. A bund is a collection trough that sits under the oil, that in the event of a leak, collects oil and prevents it from pollution the surrounding area.
It is possible to build bunds for single skin oil tanks. These bunds must leak proof, oil resistant and capable of holding 10% more than the capacity of the tank (rainwater can take up some of your bund capacity). From time to time you will need to drain rainwater from your bund. Bunds can be built of brick, concrete and other oil resistant materials. Do not be tempted to fit a permanent drainage hole; there must be a seal-able, weather resistant tap.


In the above picture, around the foundation post, you can see dark oil staining. The ground around the tank is also damp looking (oil stained). There are no weeds growing as the soil is too polluted for them to survive. The paint has come off and rust has started to take hold. There will also be a strong smell of Kerosene, solvent or petrol.

This tank needs replacing and the land around it excavating.

Remember, It is not just the oil tank that can leak, fuel lines are also prone to subsidence damage and corrosion. Therefore, check between the tank and the property for dead plants, stained soil and subsidence.

Oil tanks are very heavy and dodgy foundations will cause the tank to sink and subside. Leaks will accelerate this process.
Your tank should sit on a very solid raised platform. Therefore check how level it sits with a spirit level and check the foundations for cracking and subsidence.

Plastic oil tanks are susceptible to damage from the sun.


In the above picture, your can see the once green oil filler cap has been bleached white by the sun.
The main oil tank has become patchy in colour and once straight moulding lines have become twisted and bowed.

The obvious problem is the huge crack. This is a single skin oil tank and therefore fumes and odour can escape, causing dangerous pollution. If this crack was on the side, then the clean up bill would have been enormous.

To prevent UV damage to your oil tank, you could surround it with fencing. Building a solid brick shed around it would prevent the tank from being filled, so always take advice first before proceeding.


Fencing like this not only keeps the sun, wind and rain off your tank it also smartens up your garden.

If you are moving into a property with an oil storage tank, always get it checked over by a professional.

What can go wrong

Fuel lines from oil tanks may pass underneath more than one property, Therefore, when they leak, several houses will need evacuation. Floors will need removal, ground excavated and foundations repaired.When oil leaks, the oil builds up against foundations and wall junctions, causing serious damage.

Valuable furniture can be left damaged or smelling of kerosene.

Water pipes that run through spillage areas can be damaged, Oil can penetrate these pipes, polluting the water supply.

Residents are left seriously stressed, homeless and financially broke.

What to do in the event of a leak

  • Turn off your boiler / cooker / central heating system.
  • Check to see if you can see or smell any leaks
  • if the leak could affect a stream, pond or other water supply, call the Emergency Oil Care Hotline on 080 0807 060
  • Do not clean the spill away with detergents or a hose
  • Prevent the spill from entering drains by blocking its flow using earth, sand or commercial products that absorb oil
  • Ensure your home is well ventilated by opening windows and doors
  • Check your neighbours aren’t affected
  • Call your household insurance company
  • Contact your fuel supplier to see how quickly they can drain the remaining fuel.
  • Get copies of all recent bills, so you can estimate how much oil should be in the tank
  • Phone your employer and tell them you won’t be in that day, as this problem needs emergency attention!


Your insurance company may not pay out. They will only pay out when the spillage is due to something ‘sudden, accidental or unforeseen’. If the spillage is due to age or poor maintenance then you could be facing a massive bill. Therefore we recommend that you contact your insurance company first before commissioning the clean-up.