A bunded oil tank is a tank inside of a tank. Fuel is stored in the inner tank while the outer tank provides protection against spillage, collecting excess fuel in the bund. They’re required at industrial, commercial and institutional sites.
This bund (outside layer) must be able to take the contents of the inner tank plus an extra 10%, so in other words it must have 110% capacity to comply with the law.
Installation of an oil tank needs to comply with building regulations, which differ slightly depending on whether you are in England, Scotland, Wales or Northern Ireland.
While in some cases it may be a choice to opt for a bunded oil tank over a single layer tank, in many cases it is a legal requirement.
A bunded oil tank is required by law for commercial and industrial premises. It is also a legal requirement for a domestic setting for a wide range of reasons. In Wales, all oil tanks must be bunded by law.
So what are the reasons why you need a bunded oil tank?
1. It’s the law
A bunded oil tank isn’t always necessary for a domestic property if it is storing less than 2,500 litres of fuel. Generally up to this level it really depends on the pollution risk as to whether you opt for a bunded tank. But there are also many cases in which a bunded oil tanks is a legal requirement, even for a domestic setting:
· Where oil spills could run into an open drain or a loose manhole cover
· Where the tank vent pipes cannot be seen when the tank’s being filled, for example because the delivery tanker is parked too far away
· Within 10 metres of coastal waters or inland fresh waters like rivers, ponds, lakes or streams
· Within 50 metres of a drinking water source, for example wells, boreholes or springs
· Where oil spills could run over hard ground and reach coastal waters, inland fresh waters or a drinking water source
· If your tank holds over 2,500 litres of oil
· Where the tank is supplying heating oil to a building other than a single family home eg a block of flats or a holiday house
· Where the tank is within an Environment Agency groundwater protection (SPZ) zone 1 (find out more at www.environment-agency.gov.uk)
· Where the tank is in close proximity to any other environmental hazard
2. Longer warranty
While single skin tanks are significantly cheaper than bunded oil tanks, they also have much shorter warranties. Generally a bunded oil tank will have a 10-year warranty, while a single skin tank will have just a two-year warranty. A longer warranty means additional peace of mind and makes a bunded oil tank a wise choice, even if it isn’t legally required.
3. Avoiding environmental damage
Oil is one of the most common causes of pollution – accounting for 15% of pollution incidents every year. Oil spillages can be devastating to the local environment – from polluting waterways to destroying natural habitats and killing trees with preservation orders.
Groundwater provides a third of our drinking water in England, and also maintains the flow in many of our rivers. In some areas of southern England, groundwater supplies up to 80% of the drinking water coming out of the taps. It is crucial that we look after these sources and ensure that tapwater is completely safe to drink – and that includes minimising the risk of oil pollution.
An oil spillage is far more likely with a single skin tank than with a bunded tank.
4. Cost of an environmental clean-up
Most insurance companies won’t cover a policy holder for an oil spill. With no built-in protection from oil leaks in a single skin tank, a leak is far more likely and would more than cancel out any savings made in buying a cheaper single skin tank. The cost of an environmental clean-up could be up to £50,000, with a devastating effect on your home and family.
5. Additional safety features
To make matters, heating oil theft can also lead to spillages, a difficult phone call to the
But the good news is that bunded oil tanks have a number of safety features as standard:
- A lockable fill point to help prevent fuel theft
- A secure fuel inspection hatch designed to access the fuel and clean the tank
- An overfill protection device to prevent putting too much oil in the tank
