The principle of containment whenever practicable and safe to do so is the preferred approach to managing incidents where polluting hazardous materials or liquids have been released or generated by on-site activities, including firefighting.
This hierarchy should be used in most instances when containing contaminated run-off and spillages of polluting materials:
| Hierarchy | Activity | Description |
|---|---|---|
| 1 | Containment at source | The most effective intervention point is where the source of pollution can be controlled to stop or reduce the volume released. Methods include the use of clay seal putty, leak sealing devices, wedges, and drums. Contaminated run-off will ideally be contained at an incident scene either inside the building or as close to it as possible. |
| 2 | Containment close to source | The next point of intervention is as close to the source as possible. This may be when it is not possible to contain at source or where there has already been significant loss of pollutant. Methods include the use of grab packs, booms and pop-up pools. |
| 3 | Containment on the surface | The most common way for contaminants to enter the environment is via drainage systems. Methods to prevent this include the use of booms, clay drain mats, pipe blockers, pumps, and inflatable dams. |
| 4 | Containment in drainage system | Pollutants may be contained in drainage systems if they have already entered the system. This can be carried out using in-built pollution control devices in the drainage systems such as oil separators, drain closure valves and containment lagoons/tanks and ponds. Such a system should allow predictable volumes of run-off to be stored, although allowance should be made for rainfall and how well systems have been maintained. Portable equipment such as pipe blockers can also be used. |
| 5 | Containment on or in watercourse | The deployment of booms on a watercourse downstream of an incident is of significant benefit where a pollutant floats. Damming can be used where pollutants are mixed or do not float but is normally restricted to small ditches and streams with low flows. Booms can also be deployed around drinking water intakes. |
For further information see the Environmental Protection Handbook for the fire and rescue service.
Specific actions that may be taken to contain a release or spill at the source include:
- Remote isolation or valving down
- Site drainage/ventilation shutdown
- Retention, for example drain blocking
- Covering, for example, use salvage sheets or foam
- Damming
- Overpacking
- Patching
- Plugging
- Pressure isolation
- Solidification
- Vacuuming
- Water bottoming
- Decanting