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Seaview Wastewater Treatment Plant

The Seaview Wastewater Treatment Plant serves a population of about 160,000 in Upper Hutt, Lower Hutt and  Wainuiomata. The wastewater is treated or cleaned  through a series of screens, tanks, bioreactors, clarifiers and ultraviolet treatments before being discharged into the open sea near near Pencarrow Head/ Te  Raeakiaki where it is quickly diluted.

 

Consents

One of the nine resource consents permitting the operation of the plant, consent ‘WGN120142 [33408] Discharge Treated Wastewater to Stream ' expired in 2018. Prior to the expiry of this consent, Hutt City Council applied to Greater Wellington Regional Council (GWRC) for a new consent to temporarily discharge treated wastewater  to the Waiwhetū Stream. While the reconsenting is underway, we continue to operate under the existing consent.

In general, the consents allow Hutt City Council to:

  • discharge treated and partially treated effluent through an existing outfall,
  • discharge mixed disinfected, treated and milli-screened wastewater during and/or immediately after heavy rainfall,
  • discharge mixed disinfected, treated and milli-screened wastewater during maintenance,
  • discharge of contaminants to the air,
  • and to occupy the stream and coastal marine area with an outfall structure.

 

Join the Seaview mailing list 

If you want to receive notifications and updates about the plant, please email customer.notifications@wellingtonwater.co.nz

Seaview Wastewater Treatment Plant monthly newsletter

 For more information about plant activity and projects please go here

Odour treatment

Work is continuing to improve the capture of odours beyond the plant boundary.

Find out more about what’s planned and underway on the project page https://www.wellingtonwater.co.nz/projects/seaviewwwtp

The latest updates are available here

Investigation Reports

Seaview Wastewater Treatment Plant - Odour Deodoriser - Air Quality Assessment - October 2024
Seaview Wastewater Treatment Plant - Odour Investigation - June 2023
Seaview Wastewater Treatment Plant -Biofilter Flow Assessment -March 2024

Making a complaint

If you have a complaint about Wellington Water directly, please call 04 912 4470 or email customer@wellingtonwater.co.nz to access our free complaints process.

After hours, please contact the Hutt City Council Call Centre on 04 570 6666 / 0800 488 824.

Greater Wellington Regional Council is the regulatory agency for reporting airborne discharges 0800 496 734.  

Complaints to the Seaview Wastewater Treatment plant can be sent to the following contact details: 

First point of contact: Veolia Duty Manager - Call 0800 928 371. 

Veolia's Duty Manager contact number operates 24/7 as such complaints can be directly forwarded to them especially if the complaint is urgent and/or happened after office hours. 

When a complaint is received, the following information will be recorded: 

    • Name 

    • Contact details of the customer 

    • Nature of the complaint 

    • Date and time 

    • Location 

Complaints shall be actioned within 24 hours upon receipt and the records being written to the plant's operational incident log.  Odour and/or wastewater discharge complaints will be forwarded to the regional council.

Plant performance


Current status: Non-compliant 

Period: November 2024

Commentary:

The plant remains non-compliant for faecal coliforms (90-day geomean, 80th percentile limit). 

 

Discharges:

There was one consented discharge of fully treated effluent to the Waiwhetu Stream on 15 November due to wet weather.

 

Odour Complaints

The plant received 60 odour complaints in November. On seven occasions GWRC deemed the odour Offensive and Objectionable.

 

 

Items of significance:

 

Increase in Odour

The increase in odour relates to mechanical failures with the sludge dryer and planned maintenance to the primary sedimentation tanks. The former resulted in biological process issues and solids buildup within the system. Work is ongoing to return the plant to normal operations with recent improvements to the process noted helping reduce the odour.

 

Infringement Notice issued

GWRC issued an Infringement in relation to the Biofilter Project Abatement for late delivery of documentation relating to the project. The relevant documents have since been updated and provided.

 

Seaview Wastewater Treatment Plant performance – Odour Treatment

 

What has been completed:

Design for the milli-screening ducting replacement and air treatment for both milli-screen and dryer buildings are complete with an independent review underway.

 

What is currently in progress:

Independent review of stage 2 design will be completed in December Implementation planning procurement strategy is progressing. Odour scouting in the community continues.

Resource consents

Resource consent reports

Public health statements on the use of the treatment plant odour neutraliser

Summary

Potential health concerns associated with exposure to quaternary ammonium compounds are most likely associated with direct contact with undiluted product i.e. the staff preparing the solution.  Staff exposure risk is managed by following the correct health and safety procedures. Quaternary ammonium compounds are often part of household cleaning and disinfection products and so exposure to the public is relatively common.  Given the level of dilution of the product used in the cannon, and the distance between the placement of the cannon and potential locations for public exposure (typically this type of cannon dispersal method has an estimated droplet range of 50-100 metres) that effectively dilutes the strength further, we would not expect this to represent a health risk for the general public.  

Te Whatu Ora - Health NZ - April 2023

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In May 2024, The plant operator, Veolia, switched to a new product Odour Neutraliser Plus (SCD1100) which is manufactured by biOx Environmental. This is a stabilised chlorine dioxide product that oxidises odour molecules such as Hydrogen Sulfide. The product is safe when used as directed and is utilised in wastewater treatment plants, landfills and transfer stations throughout New Zealand. While the previous product Hi Chem Disinfectant Reodorant  presented no public health risks (see above) we decided to act on complaints from the community about the odour it generates and changed to Odour Neutraliser Plus (SCD1100). More information about this product