Curious to know what's in your tap water? Here's everything you need to know.
What does my water contain?
Tauranga's water supply contains the following:
Fluoride
Tauranga’s water supply is now fluoridated.
More information on fluoride
Silica
Is present in all natural water. Silica leaches out of volcanic rocks and soils and our aquifer fed source waters have a higher silica level than many New Zealand rivers with about 35 to 50 mg/l of reactive silica. Silica at these levels is safe for individuals of all ages to drink. Silica can form deposits on glass shower walls, kettles and toilets that look like white cloudy lines. This happens when water evaporates, increasing the silica concentration, and often occurs when water is heated. To prevent silica deposits, wipe down wet surfaces immediately after use. Silica scale can sometimes be removed by scouring the surface with a suitable cleaning product.
Natural taste and odour
Our spring-fed water has a slight natural smell due to plants and algae growing in the streams. Our purification/treatment process removes most of this odour and it’s rarely detected in cold water. But if you are accustomed to the taste and smell of drinking water elsewhere, you may notice a difference. Carbon filters can be used to remove any taste/odour or you can try keeping a jug of tap water in the fridge to minimise any issue.
Earthy taste and odour
We regularly monitor the taste and odour of our drinking water, alongside other standard testing, to ensure it meets Taumata Arowai's quality standards and New Zealand’s drinking water regulations.
In late 2023, some residents in Pāpāmoa noticed a muddy or earthy taste and smell in their drinking water. This was caused by two naturally occurring compounds in the Waiari source water —geosmin and 2-Methylisoborneol (MIB) — which are harmless but can have an earthy odour and taste.
To address this, powdered activated carbon was added during the normal water treatment process. This carbon absorbs the geosmin and MIB and is then removed in later stages of treatment.
Geosmin and MIB are common in surface water sources, such as rivers and lakes, and are typically more noticeable in warmer months. While these compounds are easily detected by our senses at low concentrations, they do not pose a health risk.
Air bubbles
These harmless bubbles make the water look cloudy or white when it flows out of your taps. It occurs when air is trapped in the water mains or during summer months when there’s an increase in water demand. Allow the water to stand for a few minutes and the air bubbles will disappear from the bottom of the glass upwards. If the water remains cloudy, contact council.
Chlorine
A small amount of chlorine is added to Tauranga’s drinking water supply to ensure the water is kept safe on its journey from the treatment plants through the pipe network to your tap. Most people don’t notice any taste or smell but if you do, you can use a water filter to remove it. Or keep a jug of tap water in the fridge with the lid off.
View our water quality and testing reports
Water hardness
Water hardness refers to the concentration of dissolved minerals, particularly calcium and magnesium, in water. These minerals can contribute to scale buildup in pipes and appliances.
The higher the calcium and magnesium content in the water, the harder the water is:
- Soft water has less than 17 mg/l equivalents of calcium carbonate
- Slightly hard water has 17 to 60 mg/l equivalents of calcium carbonate
- Moderately hard water has 60 to 120 mg/l equivalents of calcium carbonate
- Hard water has 120 to 180 mg/l equivalents of calcium carbonate
- Very hard water has greater than 180 mg/l equivalents of calcium carbonate
Tauranga’s water is classified as soft, containing 10mg/l of calcium carbonate.
We recommend following the manufacturer's guidelines for appliances, such as dishwashers, to ensure optimal performance in soft water conditions.
It is important to note that Tauranga’s water also contains dissolved reactive silica at 35 to 50mg/l. Silica does not influence traditional water hardness but can mimic hard water effects. Information on silica can be found near the top of this page.
Potential water issues
There are several things that can affect the quality of water that comes out of your taps:
Plumbosolvency
If water is left sitting for several hours in your household plumbing fittings, small amounts of heavy metals from these fittings can end up in your water. Heavy metals commonly dissolved in drinking water include lead, nickel, cadmium and copper. To avoid consuming these metals, we recommend flushing your drinking water taps (about one large glass or 500ml of water) each morning or if you’ve been away from home for a long period of time.
Discoloured water
Sediment in pipes can sometimes be disturbed during annual water main scouring or fire hydrant flushing or when we experience a large water pipe break. This can result in orange or brown-coloured tap water. To fix this, turn your outside taps on for several minutes to flush any sediment (or white air bubbles) out of the system. Once it becomes clear, check inside cold taps before trying hot taps. View current water shutdowns.
Black specks
If you see black specks in your water, this is a sign your hose and pipe fittings are worn and breaking down. Contact your plumber to organise replacement.
Grit in your toilet
This is another maintenance issue and generally indicates a problem with your internal water pipes. Contact your plumber for advice.
Yellow or green coloured water
This can occur following high rainfall events when the dissolved organics in the water increase significantly. On occasions the organics produce a yellow or greenish tinge to the water.
Want to know more about drinking water standards?
Taumata Arowai’s Drinking Water Standards for New Zealand 2022 and their Drinking Water Quality Assurance Rules 2022 outline the criteria for determining whether a water supply is safe. We regularly monitor and test our water supply to make sure we meet these standards and rules.