Contaminants in Drinking Water in NZ
Drinking water in New Zealand is generally considered safe, but depending on your water source contaminants can still be present.
Where do drinking water contaminants come from?
The type of contaminants found in your home depends largely on your water source.
Rainwater Tank Systems
Rainwater collected from roofs can pick up:
Bird poo, insects & rodents
Organic debris
Bacteria such as E. coli or Campylobacter
Contamination from certain roofing materials
Bore Water (Groundwater)
While bore water is often clear, it can contain:
Minerals such as silica or nitrates
Iron and manganese
Bacteria
Agricultural runoff contaminants
Mains (Municipal) Water
Town water is treated to meet NZ drinking water standards. However, treated water may still contain:
Fluoride (where added)
Chlorine or by-products
PFAS (in certain regions)
Minerals such as silica
Not sure what’s in your water?
Let Aqua Works test it for you.
Types of contaminants found in drinking water
Drinking water contaminants fall into three main categories.
Biological Contaminants
More common in tank & bore water. Find out more about these biological contaminants.
Chemical Contaminants
Affects tank, bore & mains water. Find out more about these chemical contaminants and how they get in your water.
Mineral Contaminants
Can be found in tank, bore & mains. Learn about minerals that can impact health and be problematic.ย
Protect your household with a water treatment solution built for your property.
How to protect your drinking water in New Zealand?
The right treatment depends on your water source and the contaminants present.
Common treatment methods include:
- Sediment filtration to remove particles
- Carbon filtration to improve taste and reduce certain chemicals
- UV disinfection to eliminate bacteria and parasites
- Whole-house systems designed for tank, bore, or mains supply
Water testing can help determine the most appropriate solution for your property.
Health risks of contaminated drinking water
Biological contamination can cause
โข Diarrhoea
โข Vomiting
โข Stomach cramps
โข Fever
Long-term exposure
Certain chemical contaminants may be associated with long-term health concerns depending on concentration and duration of exposure.
Vulnerable Groups
Babies and young children, elderly individuals, and immunocompromised people may be more susceptible to waterborne illness.
Concerned about your water quality?
Whether your home uses tank water, bore water, or town supply, understanding potential contaminants is the first step toward protecting your household.
If youโre in Warkworth, the Matakana or the Hibiscus Coast, and would like guidance on water testing or filtration options, our local water specialists can help you determine the right solution for your home.
Accurate testing for tank, bore & mains water with an accredited lab.
Identify harmful bacteria, minerals & chemical contamination in your supply.
Practical recommendations for safe drinking water and peace of mind.
Book a water test and get peace of mind
Call Raewyn on 0800 278 296 and book a water test!
FAQ about Drinking Water Contaminants in NZ
What are the most common contaminants in drinking water in NZ?
In rural areas, bacteria such as E. coli and Campylobacter are common in untreated tank water. In bore water, minerals such as silica, iron or manganese may be present. Mains water may contain fluoride, Silica or PFAS (forever chemicals).
Why does drinking water in NZ sometimes have contaminants?
Drinking water in New Zealand is generally considered safe, but depending on your water source: rain or bore water, and mains supply, contaminants can still be present.
Contaminants in drinking water may be biological (bacteria and parasites), chemical (fluoride and PFAS), or mineral or physical (silica and sediment). Many are invisible, odourless, and tasteless, which means homeowners may not realise they are present.
In areas like Warkworth, Snells Beach, Matakana, Omaha, and the wider Rodney District, down to the Hibiscus Coast (Orewa, Silverdale, Millwater), properties rely on a mix of town supply, rain and bore water. Each source carries its own potential risks.
How do contaminants get into your drinking water in NZ?
Contaminants can enter water through:
Roof collection systems
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Bird droppings
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Organic matter
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Corrosion or roofing material leaching
Groundwater pathways
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Soil bacteria
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Agricultural runoff
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Natural mineral deposits
Municipal infrastructure
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Treatment additives
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Pipe corrosion
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Environmental contamination in source water
Even sealed systems require proper filtration and maintenance.
How can contaminants be removed from drinking water?
The right solution depends on your water source and whatโs in it. Treatment may include UV systems for bacteria, carbon filters for chemicals, sediment filtration, or whole-house systems for complete protection. Aqua Works specialises in matching the correct system to your tank, bore, or mains supply, ensuring safe, reliable drinking water. Call 0800 278 296 to talk to our water specialts.
Can rainwater tanks contain bacteria?
Yes. Without proper filtration and UV treatment, rainwater tanks can become contaminated from roof runoff, bird droppings, and organic debris entering the system. Regular maintenance and the right filtration setup are essential to ensure safe drinking water. Aqua Works can assess your tank system and recommend the appropriate filtration and UV solution to protect your household water.
Is bore water safe to drink?
Bore water can be safe, but itโs not treated like mains supply and may contain minerals, bacteria, or nitrates depending on your location. Testing is the only way to know whatโs in it and if it’s safe to drink. Aqua Works can assess your bore water and install the right solution โ from sediment and carbon filters to UV or mineral treatment systems โ to ensure safe, reliable drinking water for your home. Call us on 0800 278 296 and find the best fit!
Is mains water always safe to drink?
New Zealandโs municipal water supplies are treated to meet NZ Drinking Water Standards.
However, treatment processes focus primarily on eliminating harmful bacteria. They do not necessarily remove:
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Added fluoride
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All chemical residues
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All mineral content
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Taste or odour compounds
For this reason, some homeowners choose point-of-entry or point-of-use filtration systems for additional peace of mind or taste improvement. Call us on 0800 278 296 to to discover your options.
Can Aqua Works guarantee E. coli*-free drinking water?
At Aqua Works, we guarantee E. coli*-free drinking water.
This water meets New Zealand drinking water standards and all legal requirements.
This guarantee applies only when Aqua Works specifies, installs and is employed to service the UV filtration system at regular intervals to be agreed upon at installation, depending on your water quality.
Responsibility will not be taken if the raw water quality changes. Annual testing of ground and surface water is recommended.
*E.coli-free means no active E.coli and water that passes NZ drinking water standards.
Does mains water contain fluoride in NZ?
Yes. Many municipal water supplies in New Zealand add fluoride as part of public health policy. While it meets NZ Drinking Water Standards, some homeowners prefer additional filtration. Aqua Works can install the right filtration system to reduce fluoride and improve the taste and quality of your mains water.