'Do not drink' warning issued for Waiouru tap water

Waiouru residents have been issued with a precautionary notice to not drink water from their taps due to aluminium levels from a sample taken on Wednesday.

The Ruapehu District Council said the notice was sent by the NZ Defence Force "due to a detection of chemicals in a water sample above the maximum allowable value under the Drinking Water Standards for New Zealand".

Until further notice, residents were advised not to use tap water for drinking – including making sachet juice/drinks; making ice; food preparation; brushing teeth; or preparing infant/toddler formula.

"Ruapehu District Council and the NZDF have purchased 5L water bottles which are being delivered to the NZDF base this evening.

"If you require drinking water, these can be collected at the NZDF base."

In a notice delivered to residents, the NZDF said a "non-conforming result "had come from a sample collected from the local treatment plant on June 10. The results were received this afternoon, it said.

"In a routine water sample, an aluminium concentration of 4.058 mg/L was detected. The maximum allowable value is 1.0mg/L.

"Aluminium levels in the reservoirs and reticulation network are expected to be considerably lower, but likely to still exceed the [maximum allowable value].

"This is an isolated incident resulting from a power outage on 9/10 June, which appears to have affected the treatment plant controls for dosing of poly aluminium chloride, a treatment additive."

The NZDF said the treatment plant produced the non-compliant water overnight and was shut down when the problem was identified.

"We are now flushing the plant and sending samples to the lab. We will advise when water quality has returned to normal."

It was noted the maximum allowable value for aluminium was based on long-term consumption.

"Should you choose to consume the water over the short period that this notice remains in place, the health risk is low."

However, those with severely compromised immune systems, as well as infants, pregnant women and some elderly could be at increased risk and were advised to get advice from their healthcare providers.

Water tankers would be available to residents at both Z Waiouru and Waiouru School, the notice said.

The school posted to Facebook that the issue was coming from the water supply at the Waiouru Military Camp and housing area. The school advised students to have named water bottles with them when attending on Friday. A "jerry can" would be provided for staff and students to fill their bottles.