Waiouru residents have been issued a precautionary notice to stop consuming tap water following the detection of aluminium levels significantly above the national safety standard. According to the Ruapehu District Council and the New Zealand Defence Force (NZDF), a water sample collected on June 10 registered an aluminium concentration of 4.058 mg/L, exceeding the maximum allowable value of 1.0 mg/L.
Why was the water notice issued?
The NZDF reported that the contamination resulted from a power outage on June 9 and 10, which interfered with treatment plant controls responsible for dosing poly aluminium chloride. While the plant produced non-compliant water overnight, the NZDF stated the facility was shut down once the issue was identified. Although the maximum allowable value for aluminium is based on long-term consumption, the NZDF noted that those with severely compromised immune systems, infants, pregnant women, and some elderly residents could face an increased health risk and should seek medical advice.
Where can residents access safe water?
Residents are advised to avoid using tap water for drinking, preparing infant formula, food preparation, brushing teeth, making ice, or mixing sachet drinks. To support the community, the Ruapehu District Council and the NZDF have provided 5L water bottles for collection at the NZDF base. Additionally, the NZDF has made water tankers available at Z Waiouru and Waiouru School. The school has advised students to bring their own named water bottles to school on Friday, noting that jerry cans will be provided for refilling.
What happens next for the water supply?
The NZDF has initiated a flushing process at the treatment plant and is currently sending new samples to a laboratory for analysis. While the NZDF expects aluminium levels in the broader reservoirs and reticulation network to be lower than the concentration found at the plant, they are likely to remain above the maximum allowable value for the time being. The notice will remain in place until the NZDF confirms that water quality has returned to normal levels through laboratory testing.
