Last edited 27 Jul 2021

Primary containment

Containment systems for the prevention of pollution, Secondary, tertiary and other measures for industrial and commercial premises (CIRIA C736), published by CIRIA in 2014, defines primary containment as: ‘The most important means of preventing major incidents involving loss of inventory. It is achieved by the equipment that has direct contact with the inventory stored or transferred such as storage tanks, IBCs (intermediate bulk containers), drums, pipework, valves, pumps and associated management and control systems. It also includes equipment that prevents the loss of primary containment under abnormal conditions, such as high-level alarms linked to shut down systems.'

It suggests that secondary containment: ‘Minimises the consequences of a failure of the primary storage by preventing the uncontrolled spread of the inventory. Secondary containment is achieved by equipment that is external to and structurally independent of the primary storage, for example concrete or earth bunds around storage tanks, or the walls of a warehouse storing drums. Secondary containment may also provide storage capacity for firefighting and cooling water.’

And that tertiary containment: ‘Minimises the consequences of a failure in the primary and secondary containment systems. This is done by providing an additional level of protection preventing the uncontrolled spread of the inventory such as site drainage and sumps, diversion tanks and lagoons, containment kerbing to roadways and parking areas and impervious liners and/or flexible booms. Tertiary containment will be used when there is an event that causes the escape of liquids from the secondary containment through failure or overflow (eg bund joint failure, or firewater overflowing from a bund or escaping from building/warehouse during a prolonged fire).’