Photo: AFP / FRED TANNEAU
A do-not-drink notice has been issued for the water supply in Waimate, after nitrate levels breached acceptable limits after climbing for weeks.
The water services authority Taumata Arowai said it was advised by the Waimate District Council that levels in the source water for its Lower Waihao rural supply had breached the maximum acceptable value.
Head of operations Steve Taylor said high nitrate levels posed an immediate risk to some people's health, particularly pregnant women and babies.
The maximum acceptable value (MAV) of nitrate in drinking water is 50 milligrams per litre.
Boiling water would not make it safe to drink.
"An exceedance of the MAV for nitrates poses an immediate risk to some people's health particularly pregnant women and babies if they consume the water. This differs from the MAV for arsenic which has been an issue in the Waikato and Auckland areas over the past week where the risk is based on long-term exposure," Taylor said.
An alternative supply of tankered water was available for consumers with locations available on the council's website.
"Elevated levels of nitrates in the source water for the Lower Waihao rural water supply are a known and ongoing issue," Taylor said.
Nitrate levels in the Lower Waihao source water had been rising since October.
"We encourage private suppliers and domestic self-suppliers with bore sources to have their water tested for nitrate levels by an accredited laboratory, particularly if it is being consumed by pregnant women or babies," he said.
"The water should also be tested for the presence of bacteria as it is important your water is microbiologically safe."
The council was monitoring the nitrate level, and would advise consumers when it was safe to drink again.
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