Bushfires and rainwater quality

Bushfires generate large amounts of ash and debris which can contaminate rainwater supplies. Although the presence of ash, debris, and fire retardants in rainwater are not a health risk, it could affect colour, turbidity and taste. It may still be safe to drink if you have no other options.

You can take some simple steps to ensure your rainwater supply is suitable for drinking after a bushfire.

Reducing the possibility of contamination

  • Where possible, remove any ash and debris deposited on the roof and gutters by disconnecting the inlet and brushing or washing. Care should be taken to avoid accidents through slips and falls.
  • Check the roof and guttering for dead animals and remove.
  • Do not collect the first flush of rainwater after the bushfire. Use a first flush diverter between the roof and the tank to prevent ash and other debris from entering the tank and tainting the water.

Detecting contamination

If ash and debris has been washed into the tank in large quantities before you are able to divert the first flush, the quality of the water may be affected.

If the rainwater smells, tastes or looks unusual, assume it has been contaminated. It may still be safe to drink if you have no other options.

Fire retardants

Fire retardants and foams may be deposited on roofs and can be washed into tanks when water is hosed on to the roof or when it rains.

Commonly used retardants and foams should not cause a health risk, but may affect the taste of the water if washed into the tank. Fire retardants also contain detergents that may cause the water in the tank to froth.

Removing contamination

  • Drain and clean the tank and allow it to refill with clean rainwater or fill with water purchased from a registered drinking water provider (also known as a water carter).
  • Alternatively, the water can be used for purposes other than drinking or food preparation, such as garden watering.
  • If there is a dead animal, remove the animal remains and empty and clean the tank. If you cannot empty and clean the tank straight away, remove the remains and disinfect tank water with chlorine.

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