Sometimes you may notice a change in the appearance of your drinking water. To help you understand the common reasons of these changes, we have a few simple tests you can do to help find out the possible causes. 

Likely cause

Water that is milky or cloudy and odourless is caused by fine air bubbles. Milky water is usually caused by maintenance work on the water network, such as a service shutdown during pipe repair. The issue should disappear within a couple of days after the maintenance is completed.

Why this happens

When the water is shut off for maintenance, air can get in the water main or your pipes. When the water pressure is restored, some of that air dissolves into the water. When you relieve the pressure by opening the tap, the air escapes from the water, resulting in a milky white appearance for a few minutes. This can also occur when an increase in temperature (from over-heating hot water systems) causes air to come out of the water when the tap is turned on.

Home test

Try the following test on several hot and cold drinking water taps.

  1. Fill a clean, clear glass with water and allow it to stand for 10 minutes
  2. Note whether the water bubbles clear


Bubbles clear upwards
  • If the bubbles clear upwards, this means you have air in your water.
  • Water with air bubbles is safe to drink.
  • The bubbles will clear if the water is allowed to stand.
  • Running your taps for 5 to 10 minutes may also help to clear your water pipes of the air.
  • If you have any concerns, please contact us.
Bubbles clear downwards
Bubbles that settle to the bottom of the glass can indicate particles in the water. See the discoloured water section below. 
Bubbles only appear from hot water taps
If water is milky or cloudy only when using the hot tap, this may be caused by an over-heating hot water system. This occurs when heated water releases dissolved air. If the problem persists, you will need to contact your hot water heater manufacturer or a licensed plumber.

Can you see dirt particles in your water? You may be experiencing an influx of sediment.

Dirty water can sometimes occur if we have recently carried out maintenance on the water pipes in your area. This can disturb sediment deposited in the water pipes, resulting in the tap water appearing dirty.

Find out if we have been working in your area

If you experience dirty tap water intermittently over a long period of time, the dirty water could possibly be caused by corrosion of the plumbing in your property.

Home test

Fill a clean clear glass with water and place it on a white sheet of paper. If the water is left to stand, the particles will settle to the bottom of the glass.

What you can do

Pipe corrosion
Turn on a tap briefly until the water runs clear. This may take a few minutes. You should then contact a private plumber who will provide advice on how you can improve water quality at your property.

We recommend you replace the corroded pipes within 6 months, as the corrosion products from metal pipes may cause health problems if you continue to drink this water over several years. If you are concerned about if the water is safe to drink, please contact us for advice.

After water pipe maintenance

  • Turn the front outside tap on first until the water runs clear. This will prevent any further dirty water from being pulled into the house.
  • Then work through the house from front to back, running individual taps one at a time until the water runs clear. Water inside the house is now clean.
  • Flush the tap at the back of the property last to flush out any dirt left in the pipes.

If your water still appears dirty after completing the above steps, or you are concerned about the water being safe to drink, please contact us for advice.

Does your water appear discoloured with red, orange, black or yellow and does not clear when you run your tap for a few minutes? You may be experiencing elevated metal concentrations in your water. This can be caused by:

Natural causes

Metals such as iron and manganese occur naturally in water. Iron and manganese are not always completely removed during the water treatment process and can slowly accumulate in the pipe. When this accumulated material is disturbed, it can cause discoloured water through your tap. This can last for several days however, if this is the cause, the water is usually safe to drink. If you have any concerns, please contact us. 

Fire hydrant testing

Around 98,000 fire hydrants are located in our service area. These hydrants help to protect our customers' homes and work places by providing an essential fire fighting service. Throughout the year we undertake maintenance to ensure water flow and pressure is sufficient for fire-fighters to use when fighting a fire.

The activities involved in fire hydrant testing and maintenance often lead to an increase in the water velocity during works. This can disturb sediment in the water network and lead to our customers receiving water that appears discoloured.

Is the tap water safe to drink?

Discoloured water is generally safe to drink. However, if you experience discoloured water first thing in the morning, or after long periods away from the property, you should avoid drinking the ‘first draw’ of water from the taps. Refer to the results of the home test described below.

Home test

Fill a clean clear glass with the water from your tap and place it on a white sheet of paper.


Particles floating/sinking in the water

Refer to the dirty water section below.

Blue or red water (or your sink, bath or basin is stained red or blue)

There may be corrosion of iron or copper pipes with your property's plumbing. This can occur if the tap hasn't been used overnight or for longer periods, such as after returning from a holiday.

What you can do

Turn on the tap and allow water to run clear before consuming. Your water should now return to clear.  Contact a licensed plumber who will provide advice on what you can do to improve water quality in your property.
This is most likely due to manganese in the water. You may notice it when filling a white bath or basin. Yellow-black water will stain clothing during laundering. 

What you can do 

Discoloured water is usually temporary and will clear with use. However if you are concerned about your white clothing becoming stained, run a garden tap for 10-15 minutes; using the water on your garden. Then fill a white basin to check that the water is clear. If the water is still coloured, please called us on 13 23 64 (24/7) and delay laundering white clothes. 

Stained laundry

If you are experiencing dirty water, we recommend you avoid washing light coloured clothes until the water is clear. If discoloured water has caused staining to your laundry, keep the clothing wet and contact our faults and emergencies team on 13 23 64 (24/7). We can provide you with specially formulated laundry powder to remove the staining.