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Water supply update
Auckland's tap water fully complies with drinking water standards for New Zealand and remains safe to drink.
Auckland’s water supply continues to meet drinking water standards
Test results from treated water samples taken at Waikato Water Treatment plant have met drinking water standards for New Zealand for four days running.
Latest press release: Arsenic levels in Waikato River within the ‘usual range’
Watercare results
Date: 29/11/2024
Level of arsenic: 0.0079mg/l
The ‘maximum acceptable value’ for arsenic is 0.01 milligrams per litre: Compliant
Date: 28/11/2024
Level of arsenic: 0.0068 mg/l
The ‘maximum acceptable value’ for arsenic is 0.01 milligrams per litre: Compliant
Date: 27/11/2024
The ‘maximum acceptable value’ for arsenic is 0.01 milligrams per litre: Compliant
Date: 26/11/2024
Level of arsenic: 0.0081 mg/l
The ‘maximum acceptable value’ for arsenic is 0.01 milligrams per litre: Compliant
Date: 25/11/2024
Level of arsenic: 0.011mg/l
The ‘maximum acceptable value’ for arsenic is 0.01 milligrams per litre: Above limit by 0.001mg/l
Fact sheet: Arsenic and drinking water
Background
On Tuesday 26 November, a single sample taken from the treated water at our Waikato Water Treatment Plant returned a slightly elevated result – just above the ‘maximum acceptable value’ in the New Zealand Drinking Water Standards. The ‘maximum acceptable value’ is 0.01milligrams per litre. Our elevated result was marginally above this at 0.011milligrams per litre. We immediately reported this to the water services regulator, Taumata Arowai, in line with standard procedure.
We then learned that other water suppliers who treat water from the river are reporting similar slightly elevated results. Both Taumata Arowai and the National Public Health Service have provided assurance that there is no concern for public health from drinking treated water from the Waikato River. The limits set in the New Zealand Drinking Water Standards are based on the level of risk from a lifetime of drinking the water. There is no need to boil your water. It is safe to drink straight from the tap. We have arranged for additional testing and will share the results on this page. We are working closely with other agencies involved and will provide regular updates.
Frequently Asked Questions
Frequently Asked Questions
How much arsenic had been detected in Watercare’s drinking water?A sample from the treated water at our Waikato Water Treatment Plant – taken on 25 November – returned a single result just above the ‘maximum acceptable value’ (MAV) for arsenic specified in the New Zealand Drinking Water Standards. The MAV is 0.01 milligrams per litre. Our elevated result was 0.011 milligrams per litre.
A sample from the treated water at our Waikato Water Treatment Plant – taken on 25 November – returned a single result just above the ‘maximum acceptable value’ (MAV) for arsenic specified in the New Zealand Drinking Water Standards. The MAV is 0.01 milligrams per litre. Our elevated result was 0.011 milligrams per litre.
Is my water safe to drink? Yes. Please refer to our latest press release.
The water services regulator, Taumata Arowai, and the National Public Health Service have provided assurance that the water is safe to drink, and does not need to be boiled.
The limits in the New Zealand Drinking Water Standards are based on the level of risk from a lifetime of drinking the water. Drinking water with slightly elevated levels for a short period of time is unlikely to impact your health.
Yes. Please refer to our latest press release.
The water services regulator, Taumata Arowai, and the National Public Health Service have provided assurance that the water is safe to drink, and does not need to be boiled.
The limits in the New Zealand Drinking Water Standards are based on the level of risk from a lifetime of drinking the water. Drinking water with slightly elevated levels for a short period of time is unlikely to impact your health.
How do you know arsenic levels in the treated water haven’t been high for a long time? Our test results from samples taken earlier in the month showed normal results. Other Waikato River water users have reported similar findings in their own results.
Our test results from samples taken earlier in the month showed normal results. Other Waikato River water users have reported similar findings in their own results.
How often do you test for arsenic in the treated water from the Waikato River? In line with Taumata Arowai’s testing requirements, we test for arsenic in the treated water monthly at our Waikato Water Treatment Plant.
Since receiving the slightly elevated reading, we have increased our sampling at the treatment plant to daily.
In line with Taumata Arowai’s testing requirements, we test for arsenic in the treated water monthly at our Waikato Water Treatment Plant.
Since receiving the slightly elevated reading, we have increased our sampling at the treatment plant to daily.
How much of Auckland’s water comes from the Waikato River? The Waikato River supplies about 20 per cent of Auckland’s drinking water.
We treat the water at our Waikato Water Treatment Plant in Tūākau and distribute it throughout the metropolitan network.
In most parts of Auckland, treated water from the Waikato River is blended with treated water from our dams. However, Pukekohe, Buckland, Clarks Beach/Waiau Pā, Patumahoe, Glenbrook Beach, and Drury south receive water solely sourced from the Waikato River.
The latest: Taken from 28 November press release
As a prudent water supplier, we’ve made the decision to reduce production at our Waikato Water Treatment Plant while we work with Waikato Regional Council to understand what has caused the changes in river water quality. This means we are drawing more water from our dams in the Hūnua Ranges. While we are not in a drought, summer is just around the corner – so we encourage Aucklanders to take it easy with their water use because water is a precious resource.
The Waikato River supplies about 20 per cent of Auckland’s drinking water.
We treat the water at our Waikato Water Treatment Plant in Tūākau and distribute it throughout the metropolitan network.
In most parts of Auckland, treated water from the Waikato River is blended with treated water from our dams. However, Pukekohe, Buckland, Clarks Beach/Waiau Pā, Patumahoe, Glenbrook Beach, and Drury south receive water solely sourced from the Waikato River.
The latest: Taken from 28 November press release
As a prudent water supplier, we’ve made the decision to reduce production at our Waikato Water Treatment Plant while we work with Waikato Regional Council to understand what has caused the changes in river water quality. This means we are drawing more water from our dams in the Hūnua Ranges. While we are not in a drought, summer is just around the corner – so we encourage Aucklanders to take it easy with their water use because water is a precious resource.
How do we treat water from the Waikato River?Click here for all you need to know on the treatment process.
Click here for all you need to know on the treatment process.
How does arsenic get into the water supply? Arsenic is a naturally-occurring element, particularly in geothermal and volcanic regions. It is consistently present in the Waikato River. Some of it comes from the geothermal activity near Lake Taupō and other natural sources downstream.
Arsenic is a naturally-occurring element, particularly in geothermal and volcanic regions. It is consistently present in the Waikato River. Some of it comes from the geothermal activity near Lake Taupō and other natural sources downstream.
Do Watercare treatment processes at the Waikato Water Treatment Plant remove or reduce the level of arsenic? Yes, our treatment processes are designed to significantly reduce the amount of arsenic from the raw water. This is the first time we have recorded a reading above the limit in the New Zealand Drinking Water Standards. You can learn more about our treatment processes by clicking here.
Yes, our treatment processes are designed to significantly reduce the amount of arsenic from the raw water. This is the first time we have recorded a reading above the limit in the New Zealand Drinking Water Standards. You can learn more about our treatment processes by clicking here.
Can I remove arsenic by boiling my water? Boiling water has little effect on mineral compounds in water, including arsenic. And please remember, the water is safe to drink.
Boiling water has little effect on mineral compounds in water, including arsenic. And please remember, the water is safe to drink.
Is arsenic often detected in other water sources around New Zealand? Yes. It is a naturally-occurring element, commonly found in groundwater.
Yes. It is a naturally-occurring element, commonly found in groundwater.
When did you learn of the elevated test result? The sample was taken on 25 November. We received the results on the afternoon of 26 November. We followed standard procedure and immediately notified the water services regulator, Taumata Arowai.
The sample was taken on 25 November. We received the results on the afternoon of 26 November. We followed standard procedure and immediately notified the water services regulator, Taumata Arowai.
When did you share the results with the public? When we received the elevated test result on the afternoon of November 26, we immediately notified the water services regulator, Taumata Arowai.
We arranged for additional tests and got in touch with other agencies and water suppliers who treat water from the Waikato River. Developing information indicated the issue was region-wide and likely due to changes in the natural arsenic in the river. On November 27, we worked with other agencies to put in place a joint communications response. We issued a press release and shared information on our website on the evening of 27 November.
When we received the elevated test result on the afternoon of November 26, we immediately notified the water services regulator, Taumata Arowai.
We arranged for additional tests and got in touch with other agencies and water suppliers who treat water from the Waikato River. Developing information indicated the issue was region-wide and likely due to changes in the natural arsenic in the river. On November 27, we worked with other agencies to put in place a joint communications response. We issued a press release and shared information on our website on the evening of 27 November.