Elevated levels of the toxic heavy metal Arsenic have been detected in treated water sourced from the Waikato River, potentially affecting Waikato and Auckland water supplies.  Authorities are investigating the cause. Steve Taylor, head of operations at Water Services Authority Taumata Arowai (WSA), said there was “naturally a level of arsenic” in the river, but it had been notified levels had increased recently. “I’m not sure what the reason for that increase is and that is affecting water supplies in Auckland and Hamilton,” he said. He explained the maximum acceptable value for arsenic is 0.01mg a litre – an “incredibly low amount” – but there had been levels around 0.013mg, which is “marginally above the acceptable value for drinking water”. “The level of arsenic is above what we’ve described as a maximum acceptable value, but it’s not at a level that we would suggest has a significant health effect.” “There’s no health risk in drinking that water,” Taylor said.

“What we would expect is that those levels of arsenic would reduce over time.” Taylor said it is safe for people to keep drinking tap water. “The key thing about the maximum acceptable value for arsenic is it’s designed for long-term exposure, so it’s not an acute level. ”Unlike some other levels, you know, if you exceed that level, it has an immediate health effect – that’s not the case with these levels.” Taylor said the WSA was only notified of the elevated levels on Wednesday and it had been “a very short-term situation”.

What is arsenic? The Health New Zealand Te Whatu Ora website describes arsenic as a substance found in rock, which in some situations “harms your health”. It commonly enters the body in food and water and people can swallow small amounts every day for a long time without any obvious health effects. But swallowing larger amounts may cause long-term health effects, arsenic poisoning, or death.

Someone with arsenic poisoning may suffer from:

  • Stomach pain, nausea, vomiting and diarrhoea;
  • Extreme tiredness and bruising;
  • An abnormal heartbeat;
  • A “pins and needles” feeling in the hands and feet.

It is important to note that Arsenic cannot be removed from water by boiling it

We have some filters available which can reduce the levels of arsenic in water.