There is an ongoing untreated wastewater discharge from Moa Point. We strongly recommend the public stay out of the water on the South coast of Wellington. Do not collect kai moana.

Wellington Water is responding to a significant incident at the Moa Point Wastewater Treatment Plant which has resulted in untreated wastewater discharging into Tarakena Bay on the south coast.
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Moa Point Wastewater Incident - Information Hub / Odour

Odour

Following the incident at Moa Point Wastewater Treatment Plant, there is a higher risk of odour.  

We appreciate the significant impact that odour can have on the community, and do not take this lightly. Managing and reducing odour is a top priority for us, every step of the way. 

What happened? 

On Wednesday 4 February, wastewater flooded Moa Point Wastewater Treatment Plant, causing significant damage. As a result, the plant is not fully operational and is currently discharging screened wastewater through the 1.8km long outfall pipe into the Cook Strait. Screening removes solid items like wet wipes and personal care products (i.e. pads, tampons), but the wastewater has not gone through biological or ultraviolet treatment.  

 

Why is there a higher risk of odour now? 

There are three key things which may cause more odour: 

  • When the plant stopped operating, the wastewater treatment process also stopped. This left wastewater inside the plant at various stages of treatment, including sludge (wastewater solids). It is important to remove this sludge as soon as possible before it becomes septic, which could cause significant odour and a health and safety risk to workers onsite. 
  • The plant is receiving, screening and discharging wastewater out the long outfall pipe. This process can produce odour that would normally be managed by onsite odour treatment systems, however these were also impacted by the flooding and not currently operating. 
  • Removing sludge and screened material (i.e. wet wipes) from the plant may temporarily increase odour, as it is loaded out. 

 

What are we doing to reduce the risk of odour impacting the community? 

  • We are clearing wastewater and sludge from the plant as quickly as possible. This work has been going well, and we expect the plant to be cleared by early March. 
  • Odour neutralisers and odour monitors are being brought onsite. Odour scouts are also regularly assessing odour levels within the plant boundary and in the community. We are working to restore odour treatment systems as quickly as possible, however we cannot provide a timeframe for this. 

 

Does this pose a risk to public health? 

No. Hydrogen sulphide, which tends to smell like rotten eggs, is odorous at much lower concentrations than the levels that can cause adverse human health effects. Reducing odour is important to protect community wellbeing, rather than physical health. High concentrations of hydrogen sulphide can pose a health and safety risk to workers onsite in enclosed spaces, and we have specific health and safety requirements and activities onsite to address this.  

 

Questions or concerns 

If you have any questions or feedback, please reach out to customer@wellingtonwater.co.nz or call 04 912 4400 and we’ll get back to you as soon as possible. 

Complaints can be made directly to Greater Wellington, by phoning 0800 496 734.