This Water Industry Standard provides design, manufacturing and performance requirements for manufacturers of rainwater tanks for storage of roofwater which are specifically designed for buried installations.
Performance requirements in this Standard have been drawn from AS/NZS 1546.1 and AS/NZS 4766(Int) wherever practicable. Some information has also been taken from a draft German Standard DIN 1989-3 Rainwater harvesting systems—Part 3: Rainwater cisterns.
This Standard includes two different design life criteria for buried rainwater tanks. Twenty-five years for tanks to be installed clear of any building so as not to affect any structural elements of buildings (in a similar manner to a septic tank). Fifty years for tanks to be installed under or close to buildings where structural elements of the buildings may be affected by failure of the tank.