Have the bushfires affected your water supplies with ash and smoke contamination?

With the widespread devastation of the current Australian bushfire disaster, we have been inundated with questions from households with fire affected or contaminated water supplies.

This information is designed to inform and advise you on how best to treat your water for you and your family

Bushfires have the potential to degrade water quality and alter the dynamics of stream ecosystems in many complex ways.

Most critical effects occur if there is heavy rain soon after a fire, as loss of vegetation and altered soil structure can make fire-affected soils more erodible. Runoff can carry ash, sediments and other pollutants that could jeopardise the quality of your water.

Ash or ashes are the solid remains of the fire. After large bushfires/wildfires, water supplies – particularly tank & surface water in the immediate area can become contaminated by ash and smoke.

Other contaminants include debris, fire retardant, dead birds or animals and also metals & chemicals from burned substances. Bushfire contamination can affect water supplies some distance from the fire.

The presence of ash and debris in rainwater is unlikely to be a health risk, but will likely affect the appearance and taste.

Fire retardants currently used in Australia are of low toxicity, but may also affect the appearance and taste of rainwater. Rainwater contaminated by a bushfire needs to be treated on a case-by-case basis, due to the many unknowns created by a bushfire.

Tank water may also be contaminated if the tank has been burnt by fire and/or the internal lining material or connected plumbing is damaged.

We would recommend that any water supply affected by the bushfires be managed on a case by case basis. For peace of mind, we strongly recommend that affected water supplies be tested by a certified laboratory before drinking, including testing for Arsenic and Chromium.

For sediment/ash removal, we suggest a 5 to 20 micron Pleated Washable or Poly Spun Sediment Filter, and for smoke odour/taste we would recommend a Coconut Carbon Block Filter or a Silver Impregnated Antibacterial Coconut Carbon Block Filter. The Water Filters will need to be used in an existing or new Water Filter System.

In most cases, there is also the possibility of bacteria like E.coli, so we would recommend Ultraviolet Sterilisation (e.g. UV Guard SLT Range). Then there are other considerations like flow-rates and how many people live in the home to ensure the correct water treatment system is provided.

We would also point out that filters may need to be changed more often, due to the greater load of contaminants.