For a bund to be effective it has to be watertight and impermeable to liquid egress. Unfortunately we encounter many situations where effective bunding is compromised when the floor or walls are cored to allow pipework or cables to enter the bund. Effectively it is like removing the plug from a bath and expecting it to hold water.
Often these types of penetrations are not sealed at all or they are ineffectively sealed using products which will allow water to leach out of the bund e.g. expanding foam. In both situations you run the risk of allowing contaminants to escape the bund causing pollution. If the bund is used for storing oil you will also be in breach of The Oil Storage Regulations which state the minimum requirement for a bund.
We are experienced in sealing cable/pipework entries into bunds and upgrading bunding to ensure it meets with minimum requirements of The Oil Storage Regulations. We perform this requirement for a range of clients and can seal the likes of transformer bunds which contain live high voltage cables running through them.
Sealing entries into bunds on COMAH sites may require specialist considerations, for more information on this see our COMAH bund construction page.
“(c) its base and walls must be impermeable to water and oil;
(d) its base and walls must not be penetrated by any valve, pipe or other opening which is used for draining the system; and
(e) if any fill pipe, or draw off pipe, penetrates its base or any of its walls, the junction of the pipe with the base or walls must be adequately sealed to prevent oil escaping from the system.”
The Control of Pollution (Oil Storage) Regulations
"Ideally, any pipework to fill or empty your tank shouldn’t pass through the secondary containment floor or walls (the
bund). If this is unavoidable, the joint between pipe and bund should be sealed; we recommend using a material
that is resistant to attack by the oil stored, so that the containment remains leak-proof."
Above ground oil storage tanks: Guidance for Pollution Prevention 2 (GPP 2)