E. coli in Water
Testing and UV Filtration Solutions
Call 0800 278 296 – Talk to a Water Specialist
Do you have E. coli in your drinking water?
If you rely on rainwater tanks, bore water, or other untreated water sources, protecting your drinking water from E. coli is essential. E. coli is a bacteria that can enter water supplies through animal waste, birds on roofs, contaminated gutters, or surface water flowing into tanks and bores.
E. coli cannot be seen, tasted or smelled, so testing is the only reliable way to confirm if your water is safe.
What is E. coli in drinking water?
E. coli is a bacteria found in the intestines of humans and animals. Its presence in drinking water indicates faecal contamination and suggests that harmful microorganisms may also be present, making the water unsafe to drink.
At Aqua Works we help identify water contamination through professional testing and install reliable treatment systems that protect your household water supply.
If you are unsure about the safety of your water, the first step is to have it tested. Give us a call and get peace of mind.
Found E. coli in your water? Act immediately.
Aqua Works offers a wide range of high-perforemance water treatment solutions. Our cerfified plumbers install the right filtration system to restore safe drinking water.
How E. coli gets into your water supply
E. coli enters drinking water through faecal contamination from animals or humans. Because the bacteria live in the intestines of warm-blooded animals, its presence in water indicates that waste has entered the supply.
Animal poo and roof runoff (tank water)
For rainwater tanks, contamination often occurs when birds, possums, rats or other animals leave droppings on roofs and in gutters. When it rains, this material is washed into your tank, introducing bacteria into your water supply.
Bore and groundwater contamination
Groundwater sources such as bores, springs, and wells can become contaminated if bacteria from surrounding soil or surface water enters the water supply. This is more common in rural areas or where protection around the bore is limited.
Surface water contamination
E. coli can also enter water systems through surface runoff, especially after heavy rain. Water flowing over land can carry animal waste, soil, and organic material into tanks, creeks, or groundwater sources.
Rural and agricultural environments
In rural areas in Rodney and Kaipara, contamination from manure, livestock, septic systems, or wildlife is not uncommon. Faecal material from animals or waste systems can enter water supplies and lead to bacterial contamination.
Why E. coli in water is a serious risk
E. coli in drinking water is a strong indicator of faecal contamination. This means that other harmful microorganisms — including bacteria, viruses, and parasites — may also be present.
If E. coli is detected, the water is considered unsafe to drink and should not be used without treatment. Even clear, clean-looking water can still contain harmful pathogens.
What to do if E. coli is found in your water
If a water test confirms E. coli contamination:
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Stop drinking the water immediately
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Use boiled or bottled water for drinking, cooking, and brushing teeth
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Identify the source of contamination
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Install appropriate treatment (such as UV filtration)
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Retest the water to confirm it is safe
Boiling water is a temporary safety measure only — it does not solve the underlying issue.
Health risks associated with E. coli infection
Stomach cramps and abdominal pain
Diarrhoea, which can sometimes be severe
Nausea and vomiting
Fever
Dehydration caused by fluid loss
Fatigue and weakness
Intestinal inflammation and irritation
In rare cases, kidney complications such as haemolytic uraemic syndrome (HUS)
In severe cases, the infection can enter the bloodstream causing septicaemia (blood poisoning), which may lead to organ failure and, in rare circumstances, death
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Water testing for E. coli helps to prevent health issues associated with it
The only reliable way to confirm whether your water contains E. coli is through laboratory testing. Water testing:
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Confirms whether bacteria are present
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Identifies contamination risks
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Helps determine the right treatment solution
Many households rely on tank or bore water without realising contamination can occur from natural environmental factors.
Aqua Works can arrange professional water testing and guide you through the next steps if contamination is detected. We work together with an accredited lab to get the best results for you.
If you suspect contamination or have received a failed test result, immediate action is recommended.
How Aqua Works treats E. coli and protects your water
Once contamination is identified, the next step is installing the right treatment system to ensure your water is safe long-term. Aqua Works designs solutions based on your water source, contamination risk, and overall water quality.
For most households, UV water filtration is the most effective and cost-efficient solution. UV systems disinfect water as it enters your home by using ultraviolet light to neutralise bacteria like E. coli, providing continuous protection without chemicals.
For more complex water conditions,ozone tank water treatmentcan also be used, particularly in rainwater tanks. Ozone is a powerful oxidising disinfectant that can help treat bacteria, improve water quality, and reduce organic contamination before final filtration.
With over 20 years of experience, Aqua Works has installed and serviced water treatment systems across Warkworth, the Matakana Coast and the wider Rodney District. We assess your water properly and recommend the most reliable, practical solution to ensure your drinking water is safe for your household.
Not sure what the right solution is for your water?
Every water supply is different. The right treatment depends on your water source, contamination risks, and overall water quality.
Aqua Works will assess your water, explain your options, and recommend the most reliable long-term solution to keep your drinking water safe.
FAQ about E. coli
What causes E. coli in water?
E. coli contamination usually occurs when faecal matter from animals or birds enters a water source. For rainwater tanks, this can happen through roof runoff, contaminated gutters, or animals accessing the tank area. Groundwater sources such as bores and springs can also become contaminated if the surrounding soil or surface water carries bacteria into the water supply.
How dangerous is E. coli in drinking water?
Some strains of E. coli can cause significant illness if ingested. Symptoms may include stomach cramps, diarrhoea, nausea, and intestinal inflammation. In rare but serious cases, complications can affect the kidneys. Because of these risks, drinking water containing E. coli is considered unsafe without treatment.
How do you test for E. coli in water?
Testing involves collecting a water sample and sending it to a laboratory where it is analysed for bacterial contamination. The results confirm whether E. coli is present and help determine the appropriate treatment system.
What do we do if we have had a failed water test?
If you have received a failed E. coli test and have unacceptable levels of E. coli in your water, Aqua Works will provide advice and options to ensure your water is safe. Our team can install reliable treatment systems that protect your household water supply.
If a water test detects E. coli, the water is considered unsafe to drink. The presence of E. coli indicates that faecal contamination has entered the water supply and other harmful microorganisms may also be present. Until the source of contamination is identified and treated, the water should not be used for drinking or food preparation.
As a temporary precaution, water can be boiled before use, as boiling will kill bacteria. However, boiling is only a short-term safety measure and does not solve the underlying contamination problem. A proper treatment system, such as UV disinfection combined with appropriate filtration, is normally required to provide ongoing protection.
For rural and tank water supplies, the recommended approach after a failed E. coli test is to call Aqua Works to:
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investigate how contamination is entering the system
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clean or disinfect tanks and pipework if required
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install an appropriate treatment system such as UV filtration
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retest the water to confirm it meets safe drinking water standards
Do you test drinking water for other things, or just E. coli?
Our Aqua Works drinking water analysis tests your water for coliform bacteria, Escherichia coli (E. coli) and also for enterococci, aluminium, arsenic, bacteria, lead, hormones, fluoride, fungicides, Giardia, Legionella, microorganisms, pesticides, iron, manganese, salts, sediment, heavy metals, and viruses. In most cases, these contaminants can be easily removed by a UV water filter system or ozone treatment without adding chemicals like chlorine.
Can boiling water remove E. coli?
Boiling water can kill bacteria temporarily, but it is not a practical long-term solution for a household water supply.
Permanent treatment systems, such as UV filtration, provide continuous protection without the need to boil water before use.
If my water test is clear of E. coli do I need to have it tested again?
Yes. It’s important in maintaining safe drinking water to test periodically.
Water quality can change over time due to environmental conditions, seasonal changes, or variations in the raw water source.
For this reason, periodic water testing is recommended, particularly for properties that rely on untreated water supplies. Regular servicing of UV filtration systems also helps ensure the equipment continues to operate effectively.
Aqua Works provides installation, servicing, and ongoing support for water filtration systems designed to protect rural and lifestyle properties.
How does UV water filtration remove E. coli ?
UV filtration systems use ultraviolet light to disrupt bacterial and other microorganism DNA as water passes through the treatment chamber. Once exposed to the UV light, the bacteria are unable to reproduce and are effectively neutralised.
Do UV systems need servicing?
Should water still be tested if a UV system is installed?
Occasional testing is recommended even when a treatment system is in place. Testing confirms that the system is functioning correctly and that the water supply remains within safe drinking water standards.
Aqua Works Guarantee
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 & water that passes NZ drinking water standards.
Why Choose Aqua Works
Tailored solutions for your water
We assess your water source, contamination risks, and household needs to design the right system — whether you use tank water, bore water, or mains supply.
Specialists in safe drinking water
From bacteria like E. coli to minerals like fluoride, we understand how different contaminants behave and how to treat them effectively with the right combination of filtration and disinfection.
Proven systems that work
We install reliable treatment solutions including UV filtration, reverse osmosis, and advanced multi-stage systems designed for long-term performance and water safety.
End-to-end service
We handle everything — from testing and system design to installation and ongoing servicing — so you can rely on safe, consistent drinking water.
Local expertise you can trust
With over 20 years of experience, Aqua Works has been helping homeowners across Warkworth, the Matakana Coast, and the wider Rodney District improve their water quality.