What are the rules for domestic oil tanks?

The rules at a glance

Each nation has its own rules. Some are law and some are official guidance on how to meet the law, and the table says which.

England

Approved Document J is guidance on meeting the Building Regulations for tanks of up to 3,500 litres at homes. It says a bund is needed where there is a significant risk of pollution, which it defines as any of these:

• the tank holds more than 2,500 litres
• it is within 10 m of a river, stream, lake, ditch or the sea
• spilt oil could run into an open drain or a loose manhole cover
• it is within 50 m of a well, borehole or spring
• oil could reach any of those across hard ground
• the vent pipe cannot be seen from the fill point
• it sits in the inner zone of an Environment Agency groundwater protection zone

It also says the tank should carry a label explaining what to do if oil leaks. Above 3,500 litres, a home falls under the Control of Pollution (Oil Storage) (England) Regulations 2001, the same law that covers businesses.

Wales

Wales has its own edition of Approved Document J, with the same location guidance as England. It goes further on pollution through the Water Resources (Control of Pollution) (Oil Storage) (Wales) Regulations 2016. Under these, any new or replacement tank at a home installed after 15 March 2016 must sit within secondary containment that holds at least 110% of the tank. Tanks already in use before that date are exempt until they are replaced. Natural Resources Wales enforces the rules, and in practice it means a new or replacement tank needs a bund: a single-skin tank on its own will not do.

Scotland

The old Water Environment (Oil Storage) (Scotland) Regulations 2006 have been folded into general binding rules, now part of the Environmental Authorisations (Scotland) Regulations, which SEPA enforces. A home tank of 2,500 litres or less that serves a boiler or cooker must be sound and, when it is installed or altered, must meet the building standards. The Domestic Technical Handbook then asks for a risk assessment, much like England's list, to decide whether it needs a bund. Home tanks over 2,500 litres must meet the stricter rule for all other oil storage, which includes 110% secondary containment. OFTEC notes that a building warrant may be needed in Scotland, so ask your council's building standards team before work starts.

Northern Ireland

Here the pollution test is written into the regulations themselves. A tank serving a home must be protected against oil escaping if it holds more than 2,500 litres, sits within 10 m of inland or coastal waters or within 50 m of a well, borehole or spring, could leak onto hard ground that runs to those waters, could spill into an open drain or loose manhole cover, or has a vent that cannot be seen from the fill point. Technical Booklet L says the way to meet this is an integrally bunded tank holding at least 110%. Home tanks of more than 3,500 litres also come under the Control of Pollution (Oil Storage) Regulations (Northern Ireland) 2010.

Who can do the work

The legal duty is that the installation meets building regulations. In England and Wales, a technician registered with OFTEC's competent person scheme can self-certify the work and tell building control for you. If you use someone who is not registered, you have to get a Building Control Notice from the council and pay for an inspection yourself. In Scotland and Northern Ireland, check with the council before the work, and use an OFTEC-registered technician, who will also assess whether your site needs a bund. Once the tank is sorted, compare heating oil prices for your postcode.