A bunding wall is an enclosure around oil and chemical tanks or drums that provide emergency containment in the event of failure of the tank or drum. A well designed oil and chemical bund will stop hazardous materials leaking to ground or surface water. A bunding wall is therefore a requirement of most site permits such as IPPC, IPC, IED and Waste Licences. Bunding may also be specified as part of the planning permission granted to a site.

For large oil and chemical tanks, bunding is usually provided by a concrete bund composed of walls surrounding the tank. For small tanks and for drums, plastic portable bunding is common as well as bunded steel storage cabinets.

Regulators have rules for the minimum capacity of bunds and for their design. Such rules may specify minimum and maximum heights of bund walls, location of the tanks within a bund, how to deal with jetting failure and how rainwater should be disposed of. Environmental Efficiency can advise on all aspects of bunding design and best practice.

Bunding wall integrity assessment

Regulators, require that there be a bund integrity assessment after construction and then at regular intervals to ensure that they are fit for purpose. Environmental Efficiency can undertake the assessment of all types of bunding by means of hydrostatic tests or visual assessment throughout the UK and Ireland. The allowable test method, and test duration, depends on the regulator, the type of bund and the materials stored.

Environmental Efficiency is able to fill oil and chemical bunds, using water tankers if necessary and then remove the test water after the test has been completed. Visual assessments are carried out by our in-house Chartered Engineers who all have Confined Space Entry certs.

It should be noted that visual assessments are the preferred method of assessment in the UK and in special circumstances in Ireland. Environmental Efficiency carries out hundreds of visual assessments every year throughout the UK and Ireland.

Bunding wall capacity

To ensure fitness for purpose there are rules for the capacity of oil and chemical bunds and their construction. Environmental Efficiency can advise you on the most economic bunding wall solution.

Bunds are not always required

It should be realised that not all hazardous materials require bunding. Whether to bund or not to bund can be determined by a risk assessment using the Water Hazard Class and volume of the substance being stored. Environmental Efficiency can carry out such risk assessments and where necessary advise on the design of bunding.