Seaview Wastewater Treatment Plant

Seaview Wastewater Treatment Plant Biofilter Media Replacement

Project overview

Work is underway to replace the Seaview Wastewater Treatment Plant's biofilter media to help reduce odour levels.

The biofilter media replacement is currently in progress with works having commenced in mid-November 2023. The project is expected to take three months to complete. Odour blasters are running during this time to help reduce the odour.

The biofilter media needs to be replaced from time to time to remain effective. Its job is to reduce the odour that is produced by the wastewater treatment process.

You can read more about the biofilter replacement project here

Community meeting

Wellington Water and Hutt City Council are aware that odour levels from the Seaview Treatment Plant are impacting people in the area and held a meeting on 6 December to update the community on the works.

Seaview Wastewater Treatment Plant Odour Update following the community meeting on 6 December

Several dozen people attended a Wellington Water and Hutt City Council-hosted public meeting on Wednesday evening to discuss what Council and Wellington Water are planning to address the odour issue at the Seaview wastewater treatment plant.

Council and Wellington Water acknowledged that it's been unpleasant, inconvenient, and distressful for many who live in the vicinity.

Te Rūnanganui o Te Āti Awa ki te Upoko o Te Ika a Māui, Waiwhetu marae and Wellington Tenths Trust/Palmerston North Māori Reserve Trust were in attendance as were many residents. The Hutt Park Holiday Village (Top 10) also attended. Deputy Mayor Lewis, Councillors Edwards, Brown, Dyer and Mike Fisher Petone Community Board Chair also attended along with staff from HCC, WW and GWRC. Seaview Marina and other businesses were also in attendance.

The presentation from Wellington Water explained the investigation undertaken to date and its outcome that biofilter media had reached the end of its lifespan and requires replacing. It was explained that an attempt to isolate and contain the first section of the biofilter as it was removed had not worked as hoped and resulted in the recent offensive odour.

Assurances were given by Council that we will do all we can to address the odour issue in the short and medium term.

Council is considering the draft Long Term Plan, which now has a significant investment of $13 million, to significantly improve the situation with replacement of aged equipment at the plant. This investment has been brought forward to the next three years.

Mana Whenua present requested a separate briefing and for improved communications with them. Residents and businesses expressed frustration with the time it is taking to address the issue and, in the meantime, having to live with the offensive smell.

Hutt Park Holiday Village was critical the work is being undertaken during their busiest period, reporting a significant number of negative online reviews and direct complaints from customers about the smell.

Wellington Water expects this work will be completed by 25 January by which time the odour is expected to have significantly abated.

Councillors recommended that residents continue to log complaints here when they noticed the smell and encouraged them to make submissions to the Long Term Plan process currently before Council. An online survey to gather feedback will appear on this page on 2 April 2024 and remain open throughout April.


The Veolia team has successfully replaced the biofilter media in Cells 1 & 2 on 8 December. Both cells are now operational and treating the odorous gases as designed.

The team have made excellent progress after managing to replace the biofilter media in both cells 3 and 4.

This means 4 of the 6 cells of the biofilter media have been replaced and commissioned.

Further updates will be provided as the project progresses.

Actions to be undertaken as a result of the feedback from the meeting.

  1. Regular (fortnightly) updates on the biofilter replacement work.
  1. An information sheet to be prepared for the Hutt Park Holiday Village to distribute to its customers as required. A staff member will be the key contact for the Top 10.
  1. Local signage advising of biofilter works erected.
  1. Direct contact made with Mana Whenua to discuss associated wastewater issues, specifically the overflow into Waiwhetū Stream which was raised during the meeting. An update on Wellington Water will be added to each quarterly hui with Mana Whenua.
  1. The presentation and FAQs are on the Wellington Water website here.