‘Increased risk’ of odour as wastewater continues to discharge in Wellington

Sunday, 8 February 2026

A catastrophic failure at Wellington’s Moa Point wastewater plant sent a large spill of raw sewage into the sea, sparking anger from surfers and residents. Mayor Andrew Little says the cause is still unknown and an investigation is underway.

The Moa Point Treatment Plant in Wellington is continuing to discharge screened wastewater, four days after an equipment failure saw untreated sewage discharged into the sea.

The initial incident at the plant was discovered about 1am on Wednesday, after heavy rain and flooding caused a power outage.

In an update on Sunday, Wellington Water said screened wastewater was being discharged through the long outfall pipe.

In a statement, a spokesperson said solid items like wipes and sanitary products have been removed, but it has not gone through biological or ultraviolet treatment.

They said that no wastewater has been discharged through the short outfall pipe since 9pm on Thursday. However, it could be required at short notice if there is increased flow into the plant.

The plant clarifiers have been drained down overnight, with most biological material being removed.

The spokesperson said there is an increased risk of odour in the vicinity of the plant, depending on weather conditions.

“We are proactively exploring options to minimize odour, including flushing water through the clarifiers and using odour neutralising sprays,” they said.

Wellington Water have people on the ground doing regular clean-ups of the shoreline and advising the public of the warning, including attendees at the Island Bay Festival.

“We are continuing to do daily water sampling to assess impacts on the southern beaches. Those results will be released later this morning.

Discolouration seen in the water in the Wellington harbour.

“We are working with public health authorities to inform their guidance for south coast beaches,” they said.

Wellington Mayor Andrew Little has said an inquiry into the handling of the breakdown by Wellington Water will take place, to understand “who knew what and when”.