Unusual taste or smell

The taste and smell of the drinking water we supply to your tap should be acceptable with no unusual changes. If your water tastes or smells musty or like bleach, then find out what's causing it.

If there is a faint taste or smell of bleach or disinfectant from your drinking water, it is likely due to chlorine. Chlorine is used worldwide to kill harmful bacteria in drinking water supplies. It is used to maintain safe drinking water supplies and protect public health.

We monitor and control the level of chlorine in your water carefully to keep it at safe levels. Sometimes, changes in the water treatment process may cause a slight increase in chlorine levels. This increase can affect the smell and taste of water in the water supply.

Is it safe to drink?

Almost all water supplies have chlorine added to them. The water from these supplies has a slight taste and smell of chlorine. It is not harmful to your health.

If the taste or smell becomes stronger than normal, contact us on 1800 278 278 and we'll investigate.

What you can do

If your water smells or tastes of disinfectant that is not usual and/or stronger than normal, fill a jug with tap water, cover it and store in the fridge. Leave it there overnight to reduce the smell or taste of chlorine.

If your water has a musty or earthy taste or smell, it could be caused by one of the following.

Stale water in pipes

Drinking water that's been in the pipe for a while can develop a stale, earthy taste or smell. Properties with long service connections can be prone to stagnant water if they are not flushed regularly or if the property is not occupied. It can also happen in buildings with drinking water storage tanks, such as apartment blocks.

Bacteria in your plumbing

Bacteria in your plumbing system can cause an earthy or musty smell. If you suspect that this is the case, you should contact your local plumber for help.

Algae in source water

If algae is growing where drinking water is sourced, this may cause an earthy or musty taste and smell. Algae is sometimes found in lakes or water reservoirs.

Organic substances

Certain organic substances, like MIB (2-Methylisoborneol) and Geosmin, can cause earthy or musty drinking water. These are naturally occurring chemicals, produced by algae and filamentous bacteria. They're found in lakes, rivers, streams and reservoirs and are seasonal and shortlived.

Is it safe to drink?

Drinking water with an earthy or musty taste is typically harmless. If your water suddenly develops an unusual taste or smell, contact us on 1800 278 278.

What you can do

• Talk to your neighbours to see if they are experiencing a similar earthy taste or smell.
• Run the cold water tap in your kitchen sink to clear any stagnant water in your system. If the taste or smell doesn't improve after running the tap, contact us on 1800 278 278 and we'll investigate.
• If you suspect that your plumbing system is the cause, you should contact your local plumber.