Self-bunded storage tank

Integral & Open Bunded Tanks

Choose the right solution for your bunded tanks. Whatever your requirement our bespoke designed and built bunded tanks will deliver the perfect solution.

Pollution prevention legislation is in place to protect our environment from contamination by a wide range of materials. Certain substances have specific legislation i.e. hydrocarbons, but there is a general responsibility on individuals and businesses that are storing liquids that can be harmful to the environment to have in place measures to prevent any pollution.

The storage of pouting liquids normally calls for a secondary containment system, a “bund” that stops water or hazardous liquids lost from the tank from seeping through into the environment.

Cookson & Zinn tanks exceed all applicable requirements contained within the Water Environment (Oil Storage) (Scotland) Regulations 2006, Environmental Alliance PPG2 and comparable requirements throughout the United Kingdom and Republic of Ireland.

Bunds differ from double-skinned tanks in that they are designed to contain the contents of the primary storage tank and must have a volumetric space to accommodate this, double-skinned tanks do not have the volumetric space but must have a monitoring system.

Environmental open bunded storage tank

Integral Bund

An integral bund is a very popular solution and can be used for all tank configurations, cylindrical horizontal, cylindrical vertical or rectangular.

The inner tank is connected to the outer tank via openings in the tank wall, this allows any liquid the leaks from the inner tank to be contained and stored within the outer tank.

This solution minimises the amount of space consumed as the outer “bund” tank uses the volume of the inner primary tank and adds the required 10% additional volume as a chamber, normally positioned at one end of the tank in the case of a horizontal storage tank or a base chamber in the case of a horizontal tank.

Integrally bunded tanks can have fuel polishing and dispensing equipment integrated into the bund area so any potential spillages are also contained. Our range of FuelBanks incorporates this equipment to offer a full turnkey solution to fuel storage needs.

Horizontal bundeed tank render - Cookson and Zinn

Open Bunds

Open bunds create the secondary containment system by creating a volumetric capacity of 110% of the primary tank that is completely independent of the primary tank. The most common application is where a cylindrical tank sits inside an open-topped box. The advantage that this system has over the integral bund is the ability to inspect the primary tank. This is of particular importance when storing corrosive liquids where the wall thickness of the primary containment must be checked on a regular basis. However, the disadvantage of this solution, especially if situated outdoors is the outer containment bund will fill with rainwater and must be emptied out on a regular basis.


Open top bunded tank render