Milton & OCF water supply - Manganese advisory

Manganese results from samples collected in the Milton township distribution and Otago Correctional Facility water supply exceeded its Maximum Acceptable Value (MAV) on 15 October 2025.

Manganese has a long-term MAV of 0.4 mg/L, which is set to ensure the mineral will not pose a health risk over a lifetime (70 years). For this reason, short-term exposure to water with manganese levels above the MAV is not generally considered a health risk.

Further details can be found on Taumata Arowai’s website, Manganese | The Water Services Authority - Taumata Arowai.

Manganese can cause aesthetic problems in drinking water, like staining, discolouration, and a metallic taste.

We will continue to flush the network lines to remove sediment from the water supply and collect resamples. Results of sampling is likely to take several weeks to receive.

If you receive discoloured water, please do not drink it. The discolouration comes from sediment in the water which has been stirred up from recent flushing, and there may be elevated levels of manganese, iron, and lead in the sediment.

There is a large water tank on the corner of Shakespeare Street and Spenser Street (behind SuperValue). Residents can bring their own clean containers to fill with fresh water.