Give us a call if you have any questions or concerns about your drinking water.
Why your water sometimes tastes or smells different
Fact sheet on water taste and smell (144kb pdf)
Why Pāpāmoa East water currently tastes and smells the way it does (February 2024)
Some residents in Pāpāmoa East have contacted us to say that their water has a muddy/earthy taste and smell, and they have associated that with the water having dirt in it. The reason for the taste is actually due to the presence of two naturally occurring, harmless compounds in the source water, geosmin and 2-Methylisoborneol (MIB).
Geosmin and MIB compounds have an earthy taste and odour. Human noses and tastebuds can detect geosmin and MIB at extremely low concentrations, but they are not harmful at levels present in our water. Geosmin and MIB compounds are commonly found in surface water supplies such as rivers and lakes. They are generally more prominent in warmer months and some residents have contacted us to tell us that there has been a change in the smell and taste of the water as the weather warmed up.
Geosmin and MIB cannot be removed from water using normal treatment processes. Since becoming aware of the issue in December 2023 we have begun to dose the water with Powdered Activated Carbon at the inlet of the water treatment plant, which absorbs the geosmin and MIB. The activated carbon is then removed from the water in the remaining treatment process. At the present we’re fine tuning the activated carbon dosing process to try and further reduce the taste and smell issues.
Geosmin and MIB can be detected at very low concentrations, and certain people are more sensitive to it than others. Chilling the water and adding ice cubes has helped some people notice a reduction in the taste and smell of geosmin and MIB.
We know that the water at times is not pleasant to drink, but geosmin and MIB is not harmful to people or animals, and our water is regularly tested to ensure that it meets Taumata Arowai’s quality assurance rules and the New Zealand drinking water standards.
Geosmin and 2-Methylisoborneol (MIB) are naturally occurring compounds present in our source waters that have an earthy/musty taste and odour. An increase in geosmin and MIB typically happens during the summer and goes away again when the weather cools down.
Some kinds of algae and/or bacteria present in rivers and lakes naturally produce geosmin and MIB. An increase in this production typically happens during the warmer months.
Geosmin and MIB do not pose a public health risk, but their presence can cause concern about the quality of drinking water. Utilities around the country may receive high numbers of customer complaints whenever geosmin or MIB is present in their water supply. Although these compounds are harmless, the human senses of taste and smell are extremely sensitive to them and can detect them in the water at concentrations as low as five parts per trillion (nanograms per litre). This is equivalent to 1 teaspoonful in 200 Olympic swimming pools of water.
Council has begun to monitor for geosmin and MIB in the Waiãri drinking water supply. Activated carbon is effective in reducing taste and odour issues, and we have recently started to add it to the treatment process in response to the presence of these compounds in the Waiāri source water. We are taking additional steps to improve the Powered Activated Carbon dosing system at the Waiãri Treatment Plant. Operating staff perform periodic odour tests to attempt to detect unusual odours at various treatment stages in the plant. If any unpleasant tastes or odours are detected in the filtered or finished water, the carbon dosage can be increased to remove these taste and odour compounds, that may be entering the plant.
Chilling the water and adding ice cubes has helped some people notice a reduction in the taste and smell of geosmin and MIB. We know that the water at times is not pleasant to drink, but geosmin and MIB is not harmful to people or animals, and our water is regularly tested to ensure that it meets Taumata Arowai’s quality assurance rules and the New Zealand drinking water standards.
Tauranga’s water supply is not currently fluoridated but a directive was received on the 27 July 2022, from the Ministry of Health that fluoridation of Tauranga’s water supply must be implemented by 31 July 2024.
For more information please see the Government's recent media release.
Common questions about fluoride
Fluoridation of the city’s water will cost an estimated $3.6 million capital cost. The Ministry has indicated that funding is available to assist with this cost, and has made $11.3 million available for the local councils given directives. We are awaiting information on the funding process and will update the community on the timeline when we know more.
Chlorine taste or smell
Chlorine is added to the drinking water in Tauranga to ensure the safety of the water, however, most people don’t notice it. If chlorine can be smelt in the water coming out from your household tap, you can use a water filter to remove the taste and odour. Or you can keep a jug of tap water in the fridge with the lid off and this should eliminate the chlorine taste.
Cloudy water, also known as white water, is caused by air bubbles in the water and it is completely harmless. It can be caused by trapped air due to work on the water mains. In the summer months, the warmer temperatures, combined with an increase in demand, can also cause air bubbles to form in the water. To check if the water is cloudy due to air, just fill a glass with cold water and allow it to stand for a couple of minutes. The air bubbles should disappear and clear from the bottom of the glass upwards. If the water doesn’t clear you should contact Council or have a plumber check this.
Unusual taste or smell
Tauranga draws its water from two different surface water sources and both sources have a natural, slight odour that is caused by the growth of plants and algae in the river. The purification process removes most of the odour and is rarely detected in cold water. It may be noticeable in warmer water, especially to visitors accustomed to the taste and odour of their own drinking water.
If you are sensitive to this taste/odour, try keeping a jug of fresh, cold, tap water in the refrigerator for drinking and cooking. Carbon filters can also be used to remove taste/odour.
Rusty coloured drinking water
Fire hydrant flushing and water main flushing or repairs can disturb sediment in the water mains resulting in orange or brown coloured tap water. This coloured water is not a health concern and can usually be fixed by turning on outside taps for approximately 10 minutes to flush any sediment out of the system. Once it becomes clear, check inside cold taps before trying hot taps.
Silica is one of the most abundant elements found in all-natural water. In the Pacific Rim, water generally contains high silica concentrations (50 – 100 mg/L) due to dissolving silicate contained in rock.
Silica can form deposits that show as whitish/cloudy lines, edges or marks on surfaces in toilets, (glass) shower walls and kettles. These deposits occur when water evaporates, increasing the silica concentration. This often happens when water is heated.
If the silica scale has formed, it can be removed by scouring with a cleaning product suitable for the surface material. Or better, prevent silica deposits forming, by wiping down wet surfaces immediately after use.
Silica in water is generally found in three forms; reactive, colloidal and suspended particles (e.g. sand).
Reactive silica is dissolved silica (silicon dioxide) that is slight ionized.
Colloidal silica (also known as unreactive silica) acts more like a solid than a dissolved ion.
Suspended particles are particles such as clay silt and sand.
Water mains annual scouring programme
Each year for a period of approximately six weeks, Council's maintenance contractor (Downer NZ Ltd) will carry out the annual water mains flushing programme throughout the City.
This is an annual scheduled maintenance process that ensures the water quality in our pipes remains in tip-top condition.
This may cause a temporary discoloration of water. The cause is most likely to be a build up of air or disturbance of sediment in the pipe following the flush.
Discoloured water: Try running your outside tap for 1-5 mins to clear any discolouration. If discolouration continues, please contact Council.