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.
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Find more information about plant activity and projects
Odour Project
Learn more about the ongoing works to reduce odour at Seaview Wastewater Treatment Plant
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: December 2024
Commentary:
The plant remains non-compliant for faecal coliforms (90-day geomean, 80th percentile limit) however the recent process improvements have significantly improved the daily effluent results helping the plant trend towards compliance.
Discharges:
There were two discharges in December both discharging fully treated effluent to the Waiwhetu Stream. The 16 December discharge was due to wet weather. The discharge on 26 December was due to an issue with the control system on the main outfall pump station, the cause is being investigated..
Odour Complaints
The plant received 6 odour complaints in December.
Items of significance:
Plant performance improvement
The biological process has significantly improved as the solids buildup within the system was reduced allowing the plant to reach near-normal operation. The reduction in odour as the month progressed was a notable by-product of these improvements. Planned maintenance to the final two primary sedimentation tanks will commence early 2025 which should further stabilise the plants process.
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 and design approval of stage 2 design will be completed in January.
Implementation planning procurement strategy is progressing.
Odour scouting in the community continues.
Resource consents
WGN050359 [24539] Discharge Treated Wastewater to Coastal Marine Area (Seaview WWTP)
WGN120142 [31740] Construction to Coastal Marine Area Maintenance (Seaview WWTP)
WGN120142 [33406] Discharge of Treated WW to Fresh Water Wet Weather (Seaview WWTP)
WGN120142 [33407] Discharge of Treated WW to Coastal Marine Area Maintenance (Seaview WWTP)
WGN120142 [33408] Discharge Treated Wastewater to Stream (Seaview WWTP)
WGN930193 [1] Contaminants Discharge to Air Outfall Structure (Seaview WWTP)
WGN930193 [2] Contaminants Discharge to Air Venting Structure (Seaview WWTP)
WGN950162 [1] Contaminants Discharge to Air WWTP (Seaview WWTP)
WGN930194 Land Occupation by Outfall Pipeline and Structures (Seaview WWTP)
Compliance reports
Seaview Wastewater Treatment Plant - 2021 2022 Compliance Report
Seaview Wastewater Treatment Plant - Consent Compliance Report 2022 - 2023
Seaview Wastewater Treatment Plant - Consent Compliance Report 2023 - 2024
Resource consent reports
Annual Reports:
Seaview Wastewater Treatment Plant Annual Resource Consents Report 2023-24
Seaview Wastewater Treatment Plant Annual Resource Consents Report 2020/2021
Seaview Wastewater Treatment Plant and HCC/UHCC Trunk Main Annual Resource Consents Report 2019/2020
Seaview Wastewater Treatment Plant Annual Report 2021/2022
Seaview WWTP 2022/ 23 Annual Consents Report
Quarterly Reports:
Seaview Wastewater Treatment Plant October - December 2024 - Quarterly Resource Consents Report
Seaview Wastewater Treatment Plant July - September 2024 - Quarterly Resource Consents Report
Seaview Wastewater Treatment Plant January - March 2023 - Quarterly Resource Consents Report
Appendices:
Seaview Wastewater Treatment Plant Annual Consents Report 2023-24 - Appendix ||| Trade Waste
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
_________________________________
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
Independent assessment on the impact of the odour neutralisers
Regarding any impact of the odour neutralisers, an independent assessment has been undertaken and the report concluded that the potential health risks regarding the use of the odour deodorisers are low and acceptable in accordance with New Zealand Guidelines. A copy of the report can be found here.
Odour Investigation Reports
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:
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discharge treated and partially treated effluent through an existing outfall,
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discharge mixed disinfected, treated and milli-screened wastewater during and/or immediately after heavy rainfall,
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discharge mixed disinfected, treated and milli-screened wastewater during maintenance,
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discharge of contaminants to the air, and
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to occupy the stream and coastal marine area with an outfall structure.