DGSM Information Paper No.10 - Spills containment and clean-up ...

3.5 Capacity of spills containment systems for package stores
For package stores it is recommended in most circumstances to apply the following approach
to determine the capacity of the spills containment system:
100 % of the capacity of the largest package; plus
25 % of the maximum intended storage capacity up to 10 000 litres; plus
an additional 10 % of the capacity in excess of 10 000 litres; plus
an additional capacity for fire water.
For example, if a package store contains 15,000 litres of packaged dangerous goods and the
largest container is 200 litres, the containment capacity would be calculated as follows:
200 + 2500 + 500 = 3200 litres plus additional fire water capacity
3.6 Other Issues
Storage of Incompatible Goods
Occupiers need to ensure that tanks of incompatible dangerous goods are never stored within
the same spill containment area. Tanks of incompatible goods should be located in separate
spill containment areas.
Incompatible dangerous goods must not be stored in the same spill catchment area because
of the potential for the materials to react dangerously together. Other compatible dangerous
goods may be stored in the same catchment area provided appropriate distances are observed.
At least 3 metres segregation distance would be appropriate for goods that do not react
dangerously.
All incompatible dangerous goods of Packing Group I or II should be assumed to react
dangerously, unless it can be proven otherwise. Concentrated acids and alkalis are examples
of incompatible goods that may react dangerously together.
Distance from containers to bund wall
Bunded compounds need to be constructed so as to ensure that punctures or ruptures of
containers do not cause a jet of liquid to pass over the edge of the bund wall. Certain
minimum distances should be maintained between any container and its bund wall.
Many Australian Standards recommend at least 1metre distance between a tank wall and its
bund wall, measured from the top inside edge of the bund wall to the outermost edge of the
tank surface.
This distance may increase depending on the height of the container. A good rule of thumb is
to ensure that containers sit further from the top inside edge of the bund wall than the line
defined by angle A in Figure 1 3 (the illustration is for a horizontal cylindrical tank on a stand).
The distance to the bund wall should ensure that the angle A is more than 26.5˚. In other
words, the ratio of the horizontal distance over the vertical distance from the tank edge must
be greater than 0.5.
3
Adapted from Figure 5.2(b) in Australian Standard AS 1940 “Storage and Handling of Flammable and
Combustible Liquids”.
DGSM Information Paper No. 10 Spills Containment and Clean-up (December 2003)
CHEM Services, Department of Emergency Services Page 4