Drinking Water in New Zealand

Town Supply

If you live in a town or city then the water that comes out of your tap probably comes from the local 'town supply'. Most town supplies are run by the local council who source the water from a nearby river or from an underground aquifer and treat it in a water treatment plant.

The government requires all public water supplies to meet the Drinking Water Standards for New Zealand, which set out maximum acceptable levels of contaminants and provide guidelines for monitoring and treatment and generally speaking, New Zealand has very high quality drinking water. As you've probably heard on the news though, there are the odd times when problems arise in a town supply which can result in an outbreak of stomach upsets or where a contaminant such as lead is too high.

Another point to consider is your house plumbing - Your local Council is responsible for ensuring the water to your toby box meets the New Zealand standard, but past the toby box, it is up to you to ensure your pipes and faucets in your house are up to scratch. Many of the old pipes and taps in New Zealand contain high quantities of lead which can dissolve into the water that you then drink. Plumbsolvency is another problem in many areas of New Zealand which is detailed further below.

Rural Water Supply

In rural areas of New Zealand, drinking water supply can be more challenging compared to urban areas as many properties may rely on private bore water, surface water or rainwater tanks. As a result, it is up to the individual property owners to ensure the quality and safety of their drinking water supply.

Private bore water is sourced from underground aquifers and may require treatment to ensure its safety for drinking. Bore water is generally considered the safest of the rural water supplies in New Zealand, however it is still susceptible to contamination which is largely dependent on the depth of the bore and the associated aquifer; the shallower the bore, the higher the likelihood of contamination from above-ground sources.

Rainwater harvesting is another common method of drinking water supply for rural properties. Rainwater is collected from roofs and stored in tanks for later use. However, the quality of rainwater can be affected by a range of factors, such as air pollution, bird droppings, and algae growth in the storage tanks. It is recommended that rainwater be treated and tested regularly to ensure its safety for drinking.

Surface water collected from rivers, lakes, and other surface sources is another source of water supply in rural areas of New Zealand. While surface water can be of high quality, it is susceptible to contamination from a range of sources, including agricultural runoff, human sewage, and industrial waste. This can pose a risk to human health and result in waterborne illnesses, such as gastroenteritis.

It is recommended that all rural water supplies be tested regularly for a range of contaminants and appropriate filters and treatments are in place. If you are a 'water supplier' ie; you supply water to anyone outside your household for drinking purposes, then under the Drinking Water Standards for New Zealand you have an obligation to test and treat the water as necessary.

Plumbosolvency

Most drinking water in New Zealand is plumbosolvent. This means the water can dissolve small amounts of metals it may encounter, such as lead and copper in your plumbing fittings (like pipes and taps). Drinking water with high levels of heavy metal is a health concern. 

As discussed above, drinking water suppliers have a duty to ensure that the water they supply to you complies with the Drinking Water Standards, which sets maximum levels for metals in water. However, drinking water suppliers are only responsible for drinking water quality up to the point of supply, which is normally the toby outside of your property.  

There may be metals in the plumbing within your property such as in the taps or other fixtures, which can have an impact after the water has been supplied. Newer, better quality fittings are likely to contain less harmful metals. Taumata Arowai, the water services regulator for New Zealand recommend: 

  1. When you first turn on your tap in the morning, run your tap to fill a large cup of water.   
  2. Tip the cup of water down the sink.
  3. You should also do this at other times when your tap has not been used for a while, like when you come back from holiday. 

This will help remove metals that might have been dissolved or absorbed from your plumbing fittings.  

Water Testing

There are a range of instant water test kits available for sale on our website to give you peace of mind. If you are a water supplier, then a laboratory test is required under the Drinking Water Standards for New Zealand.

The following table briefly outlines the key testing parameters in drinking water and why it is important to test for them.

Parameter

Details

Alkalinity

Alkalinity is a measure of the water's ability to resist changes in pH levels. High alkalinity in water can cause scaling and affect the taste of the water. It is important to test for alkalinity to ensure that the water is not corrosive to pipes and to ensure that it is safe for human consumption.

Free Chlorine

Free chlorine is a disinfectant used to kill bacteria and viruses in water. Testing for free chlorine is important to ensure that the water is safe for drinking and free from harmful bacteria and viruses.

Total Chlorine

Total chlorine includes both free and combined chlorine. Testing for total chlorine is important to ensure that the water has been properly disinfected and to avoid potential health risks from overexposure to chlorine.

Chloramines

Chloramines are a combination of chlorine and ammonia that are used as a disinfectant in some water treatment plants. Testing for chloramines is important to ensure that the water is safe for drinking and free from harmful bacteria and viruses.

Hardness

Hardness is a measure of the concentration of dissolved minerals such as calcium and magnesium in water. High levels of hardness can cause scaling in pipes and appliances, affect the taste of water, and can lead to skin irritation. Testing for hardness is important to ensure that the water is safe for human consumption and that it does not damage pipes and appliances.

pH

pH is a measure of the acidity or alkalinity of water. Testing for pH is important to ensure that the water is not too acidic or alkaline, which can cause corrosion in plumbing systems, can affect the taste of water and potentially cause health problems.

Nitrate

Nitrate is a compound that can enter drinking water sources from fertiliser and animal waste. High levels of nitrate in water can cause health problems, particularly in infants and pregnant women. Testing for nitrate is important to ensure that the water is safe for human consumption.

Iron

Iron can enter drinking water sources from natural deposits or from corroded pipes. High levels of iron in water can cause staining of clothes and appliances, affect the taste of water, and potentially cause health problems. Testing for iron is important to ensure that the water is safe for human consumption and does not damage pipes and appliances.

Copper

Copper can enter drinking water sources from corroded pipes. High levels of copper in water can cause gastrointestinal problems and potentially lead to liver or kidney damage. Testing for copper is important to ensure that the water is safe for human consumption.

Total Coliforms

Total coliforms are a group of bacteria that are found in the environment and in the intestines of humans and warm-blooded animals. Their presence in water can indicate the potential presence of harmful bacteria and viruses. Testing for total coliforms is important to ensure that the water is safe for human consumption.

E-Coli

E-Coli is a specific type of coliform bacteria that is found in the intestines of humans and animals. Its presence in water can indicate the potential presence of harmful bacteria and viruses. Testing for E-Coli is important to ensure that the water is safe for human consumption.

Pesticides

Pesticides can enter drinking water sources from agricultural runoff or from industrial waste. High levels of pesticides in water can potentially cause health problems. Testing for pesticides is important to ensure that the water is safe for human consumption.

Lead

Lead can enter drinking water sources from corroded pipes and plumbing fixtures. High levels of lead in water can cause developmental problems in children and potentially lead to other health problems. Testing for lead is important to ensure that the water is safe for human consumption.

Further Information

The following links will provide you with additional information about drinking water and the Drinking Water Standards for New Zealand:

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