Guidance on use of rainwater tanks

Tank cleaning

Page last updated: March 2011

Where cleaning necessitates entering the tank, take care to ensure adequate ventilation is provided and an additional person is in attendance. Advice on working in confined spaces should be available from occupational health and safety authorities in each state and territory.

It is important to check the structural condition of the tank before choosing a method of cleaning. Cleaning should generally be limited to removing accumulated sediments, leaf litter etc. Harsh cleaning methods may accelerate deterioration, for example, by removing the protective layer on the inside walls of a steel tank which will lead to tank corrosion. So called ‘white rust’ caused by zinc-rich oxides on the inside of metal tanks is not a health risk and does not need to be removed.

Cleaning agents that might release hazardous fumes or adversely affect water quality after cleaning should not be used. After cleaning, it is recommended that the internal walls and floor of the tank be rinsed with clean water. Rinse water and sediment should be run to waste.

Discarded water should be diverted away from tank foundations, buildings and other structures. Water containing cleaning agents should not be allowed to flow into street guttering.