What Do I Need to Know About Bunds?

If you store any liquids on your site, it is good practice to bund everything for pollution prevention.  This blog will explain the key points you need to know about bunds to prevent pollution from leaving your premises.

What is a bund?

A bund is an outer case holding the primary container.  Often called secondary containment, it can fully encase the container (so it is no longer visible), or the tank could sit in or on top of the bund.  Bunds can be fixed e.g. a lined masonry bund with a base, or bunds that are smaller and can be moved around.

Why do I need a bund?

Bunds are designed to capture liquids if the primary container fails or is damaged and also captures drips or leaks.  This means that liquids are captured and held in a container until they can be safely removed rather than escaping the site and causing pollution.

What features should my bund have?

The bund should be large enough to contain all liquids in the event of full failure.  It should be 110% of the primary container or, if there are multiple containers in one bund, it should either be 110% of the largest container or 25% of the volume of all containers combined, whichever is greater.  The bund should be in good condition and capable of fully containing the liquid e.g. masonry bunds should be lined.  The bund should not have any breaks in it for valves, pipework or taps and ideally should contain all ancillary pipework.

What do I need to do when I have a bund?

Bunds must be checked regularly to ensure they are in good condition.  You should be checking for any cracks, chips or signs of leaks or seeping from the bund.  This should be done regularly (weekly or monthly) and the results recorded so any deterioration can be identified quickly.  You may also wish to carry out more extensive bund checks to ensure there are no issues with integrity that may not be picked up at a visual inspection.  Any issues associated with the bund should be addressed quickly so that integrity can be maintained.  You need to have a procedure in place for dealing with bund water.  If your bund is exposed, it will fill up with rainwater and you will need to empty your bund to maintain the required capacity and have the correct paperwork in place for removal.  You may consider covering your bund to make sure rainwater can’t get in, but you will have to check under the cover regularly for water.

If you are storing liquids on site, it is good practice to bund them so any spilled or leaked material is captured rather than escaping and causing pollution.  Bunds should be designed to fully contain any spilled liquid and be regularly checked to ensure any problems are identified and addressed.