Geosmin and Methylisoborneol (MIB) are commonly occurring natural compounds found in water sources. They can affect the taste and odour of treated drinking water.
Geosmin and MIB are usually more prominent during the warmer months when they are produced by blue-green algae in raw water storages like dams and weirs. They can also be produced by bacteria in water and soil.
Learn more about blue-green algae
Geosmin and MIB have a very strong, earthy taste and odour. They 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.
Although the taste and odour from Geosmin and/or MIB 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.
Our water treatment plants use ‘powdered activated carbon’ dosing units to remove Geosmin and/or MIB. The compounds bond with the carbon and are removed from the water. Unfortunately, sometimes not all the Geosmin or MIB can be removed, however this is purely an aesthetic issue and treated water is safe to consume.
Recently we have seen Geosmin and MIB 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 these compounds and adjusting our treatment processes as necessary.
It is unclear on how long the high levels of Geosmin or MIB will last, however traditionally as the weather cools, levels of the compound decrease.
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.
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.