In many industries bunds are widely used to act as secondary containment vessels to protect against the consequences of the failure of a primary containment vessel (e.g. storage tank, drums, IBCs).
In recent years, legislation passed by the Environment Agency and the Scottish Environment Protection Agency (SEPA) has made it mandatory for most oil storage facilities to include a secondary containment vessel such as a bund which is capable of storing at least 110% of the capacity of the largest tank or 25% of the total storage capacity, whichever is the greater.
Bund walls are normally constructed from brick or block, however where they need to contain large volumes of liquid they may also be constructed from reinforced concrete. Detailed information the construction of bunds ranging from 1000 to 25000 litres can be found in CIRIA Report R163, “Construction of bunds for oil storage tanks.
The bund lining will need to be resistant and impermeable to the liquids being stored. The Environment Agency’s guidelines for oil storage tanks (PPG2)² state that “the secondary containment system should be impermeable to oil and water…”
ECS Epoxy Coating is a popular choice for bund lining as it is resistant to a wide range of chemicals. However other products such as Vandex BB75 and Vandex Polycem Z, and DryBase Vapour Membrane can offer a better solution in some circumstances (e.g. in outdoor bunds exposed to sunlight or bunds designed to contain chemicals that are incompatible with epoxies) – it is therefore advised that you contact our technical department to discuss the most appropriate solution for lining any particular bund.
The wall-floor junction is usually the most vulnerable part of any bund, so it is normally recommended that a Unimortar 1 fillet is formed around the wall-floor junction to provide additional protection.
¹ CIRIA Report R163 “Construction of bunds for oil storage tanks” ISBN: 978-0-86017-468-4. Available from www.ciria.org.
² Polution Prevention Guidelines – Above Ground Oil and Storage Tanks: PPG2 – available for download from www.environment-agency.gov.uk.