Secondary Containment (Bunding)
Secondary Containment or Bunded Areas require a seamless, waterproof lining to prevent contamination of liquids into the surrounding environment.
Also known as a form of 'Spill Control' bunded areas are recommended to protect the surrounding environment from contaminants such as fuel, oil, chemicals or liquid waste.
Epoxy type products have traditionally been used for coating bunded areas due to their high adhesion to concrete and chemical resistance. However, epoxies have one major disadvantage - they have no elongation and over time will not bridge hairline cracks in concrete nor will they stretch to accommodate the cyclical daily expansion and contraction of large sections of substrate. Other types of membranes such as Acrylics and Bituminous membranes have also been used but they lack UV resistance and over time become brittle and crack.
Tufflon-P90 is a new generation of coating material based on polyurea and has all the benefits of epoxies - high adhesion to the substrate and excellent resistance to chemicals and hydrocarbons - but with the extra advantage of being highly and permanently elastomeric. With elongation greater than 400% and also being puncture resistant, the membrane will move with cyclical changes in the concrete substrate and won’t crack or peel.
The Environmental Protection Agency (EPA) suggests that all chemical containment areas (or bunds) must be large enough to hold at least 110% of the contents of a tank. Any contained liquid other than rain water should have a bunded area to prevent contamination into the environment.
For further information please visit the EPA website in your Australian State or Territory.
These applications are found in mining, civil, construction and commercial industries.
An excerpt from the Gladstone City Council in Queensland gives the following suggestions regarding bunding requirements:
"A bund is an embankment or wall of brick, stone, concrete or other impervious material, which may form part or the entire perimeter of a compound and provides a barrier to retain liquid. Since the bund is the main part of a spill containment system, the whole system (or bunded area) is colloquially referred to within the industry as the ‘bund’. The bund is designed to contain spillages and leak from liquids used, stored or processed above ground, and to facilitate clean up operations. As well as being used to prevent pollution of the receiving environment, bunds are also used for fire protection, product recovery and process isolation."
Chemical resistant - see chart
Quick to apply - fast return to service
Will not flake, peel, crack or blister
Smooth and seamless easy-clean finish