Skip to content Skip to navigation
Geosmin FAQ

Geosmin FAQ

Frequently asked questions about Geosmin and your water supply.

Below are frequently asked questions about Geosmin and its effects on treated water.

What is Geosmin?

Geosmin is a commonly occurring natural compound found in water sources. It can affect the taste and odour of treated drinking water.

What causes Geosmin?

Geosmin is usually more prominent during the warmer months when it is produced by blue-green algae in raw water storages like dams and weirs. It can alos be produced by bacteria in water and soil.

Learn more about blue-green algae

Why does it affect the taste and odour of my drinking water supply?

Geosmin has a very strong, earthy taste and odour. It can be smelled at very low concentrations (in the parts-per-trillion range). The compounds are generally present in all drinking water but below noticeable levels.

Is my treated drinking water safe to consume?

Although the taste and odour from Geosmin may be unpleasant, it is purely an aesthetic issue. Treated drinking water is safe to consume and meets parameters set by the Australian Drinking Water Guidelines and the Safe Drinking Water Act.

We appreciate people’s patience and understanding while we work to minimise taste and odour issues.

How does North East Water treat for Geosmin?

Our water treatment plants use ‘powdered activated carbon’ dosing units to remove Geosmin. The compounds bond with the carbon and are removed from the water. Unfortunately, sometimes not all the Geosmin can be removed, however this is purely an aesthetic issue and treated water is safe to consume.

Even after the treatment process, why does my drinking water still have taste and odour?

Recently we have seen Geosmin levels up to 20 times more concentrated than in previous years. This has proved challenging for our treatment processes.

We have increased the use of carbon dosing to remove the compounds. We are also undertaking more sampling for Geosmin and adjusting our treatment processes as necessary.

What areas are affected?

Testing has shown there are higher than normal levels of Geosmin in the Mitta Mitta arm of Lake Hume at Tallangatta and in Lake Mulwala at Yarrawonga. There is the possibility that Geosmin concentrations in Lake Hume could increase in other areas as blue-green algae grows and produces the compound. This could include other areas of Lake Hume and/or the Murray River.

How long will this issue last?

It is unclear on how long the high levels of Geosmin will last, however traditionally as the weather cools, levels of the compound decrease.

Is there anything I can do to reduce the unpleasant taste?

Some people have reported that putting water in a jug in the fridge can help with the taste and odour issues. You could also consider adding lemon, orange, watermelon or mint to help.

Am I eligible for a refund on water usage charges because of taste and odour issues?

We realise water taste and odour is an issue for some customers, however we are unable to offer a refund or compensation as it is purely aesthetic. Treated drinking water is safe to consume and meets parameters set by the Australian Drinking Water Guidelines and the Safe Drinking Water Act.