Porirua Wastewater Treatment Plant
At the Porirua Treatment Plant, sewage travels through a series of screens, bioreactors, clarifiers and ultraviolet treatments before being discharged as liquid into Rukutane Point.
For more information on how wastewater is treated, go to the treatment process.
The consent for the Porirua Wastewater Treatment Plant (WWTP) was recently renewed.
In general, the consents allow Porirua City Council to:
- discharge treated and partially treated effluent at Rukutane Point through an existing outfall,
- discharge contaminants to the air
- and permission to occupy the coastal marine area with a concrete deflection wall and outfall structure.
Upgrades to the plant’s UV treatment system and hydraulic capacity were completed in mid-2023. The plant is now able to treat a peak flow of 1,500 litres per second. In heavy rain the amount of wastewater delivered by the network can reach up to 1,300 litres per second.
Planning Ahead
Over coming decades, we want to keep reducing the volume and number of overflows from the wastewater network.
Overflows happen when rainwater overwhelms the wastewater pipe network, causing untreated wastewater to flow over land or into freshwater. This is objectionable, and abhorrent to mana whenua. Overflows contain bacteria that may make people sick if they come into contact with contaminated water.
We know where and when overflows happen from our monitoring, incidents reported by the community, and network modelling. Wellington Water and Porirua City Council have a view of where work is needed to reduce overflows and have already started on improvements. For example, the central wastewater storage tank will reduce overflows into Porirua Stream, and the Eastern Porirua regeneration project will reduce overflows into Kenepuru Stream.
Resource consents
Resource Consent Application 2020 - 2022
Independent Hearing Panel Decision Report (relating to the 2023 Resource Consent Applications: Renewal of existing consents for discharge of treated sewage to coastal water, and associated discharge to air from the Porirua Wastewater Treatment Plant)
WGN200229 [36816] Discharge to Coastal Marine Area (Porirua WWTP)
WGN200229 [36727] Contaminants Discharge to Air (Porirua WWTP)
WGN980083 [03] Land Occupation by Outfall Structure (Porirua WWTP)
Resource consent reports
Annual Reports:
Porirua Wastewater Treatment Plant Annual Resource Consents Report 2021/2022
Porirua Wastewater Treatment Plant 2020/2021 Annual Resource Consents Report
Porirua Wastewater Treatment Plant 2019/2020 Annual Resource Consents Report
Porirua Wastewater Treatment Plant 2018/2019 Annual Resource Consents Report\
Porirua Wastewater Treatment Plant FY22/23 Annual Resource Consents Report
Porirua Wastewater Treatment Plant, GWRC Compliance Monitoring Report 2022 - 2023
Quarterly Reports:
Porirua Wastewater Treatment Plant October December 2022 Quarterly Resource Consents Report
Porirua Wastewater Treatment Plant July September 2022 Quarterly Resource Consents Report
Porirua Wastewater Treatment Plant April - June 2022 Quarterly Resource Consents Report
Porirua Wastewater Treatment Plant January - March 2021 Quarterly Resource Consents Report
Porirua Wastewater Treatment Plant October - December 2020 Quarterly Resource Consents Report
Porirua Wastewater Treatment Plant July - September 2020 Quarterly Resource Consents Report
Porirua Wastewater Treatment Plant April – June 2019 Quarterly Resource Consents Report
Porirua Wastewater Treatment Plant January March 2023 Quarterly Resource Consents Report
Plant performance
Current Status: Compliant (with noted issue)
Period: February 2024
Commentary:
The plant experienced a technical non-compliance in mid-February with Faecal Coliforms exceeding the daily limit for two consecutive days. The spike in results is being investigated and outcomes will be reported once known. The daily results have since returned to within the effluent consent requirements.
Discharges:
No discharges in February 2024.
Odour complaints:
There was one odour complaint in February. Due to the nature of the complaint, a response will be issued through the LGOIMA process.
Items of significance:
UV Performance Issues:
The project team continue to implement process and control system modifications to fine tune the mechanical operation. The UV manufacturer is supporting WWL engineers in this process. Changes made to date have improved UV performance during high flows. The system will continue to be monitored while these ongoing adjustments are being implemented.
Centrifuge mechanical issues:
One of the plants two centrifuges failed, reducing theplants dewatering capability. This led to an increase in suspended solids in the biological process. The failedcentrifuge is undergoing urgent maintenance and isexpected back in service in early March.
Odour Survey Reports
Complaints
Complaints Procedure
Complaints to the Porirua Wastewater Treatment plant can be sent to the following contact details:
Veolia Duty Manager (First Point of Contact): 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.
Wellington Water: Call 04 912 4470 or email customer@wellingtonwater.co.nz.
When a complaint is made, the following information will be recorded:
-
-
Name
-
Contact details of the customer
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Nature of the complaint
-
Date and time
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Location
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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.
Complaints Register
Odour Complaints
|
Date of Complaint Submitted |
Date of Incident |
Complaint description/ Characteristics as per the complainant |
Wind Direction |
Average Wind speed (Km/Hr) |
Inlet Tunnel Vent Fan Operation – 24 hr format |
Plant Operations |
|
24/02/2024 |
24/02/2024 – 9:38 am |
We received a formal complaint letter from one of the Pikarere farm resident relating to odour. |
NW |
31.3 |
OFF |
Normal |
|
18/01/2024 |
18/01/2024 -20:47pm |
I would like to know what is been done about the odour at the plant I haven’t heard back what the plan is but tonight smells bad last night also and Sunday and Monday. |
NW |
16.1 |
OFF : (00.00 – 00:36) , (05:00- 23:59) ON : (00:37-04:59) |
Normal |
|
08/01/2024 |
08/01/2024 – 12:19 pm |
Have just been to the front gate of the farm and the smell of sewage ( human waste) is very strong and frankly unacceptable. Lately in northerly conditions there has been strong odour. What controls are on the fan which I believe is the source of the odour ? Does it turn off automatically as proposed in the Update Memo at the meeting at Porirua on26 October. Please let me know what action is currently being taken as the odour/smell is unacceptable and clearly in breach of the conditions of the resource consent. Please treat this email as a formal complaint to be recorded in the complaints register |
NW |
24.4 |
OFF : (01:05 – 23:59)
ON : (00.00 - 01:04) |
Normal |
|
03/01/2024 |
03/01/2024 – 23:01 pm |
last 2 months has been the smelliest the Tītahi Bay sewer treatment plant has ever been mainly in the evenings .Tonight was really bad up at my house and 3 nights ago I called Veolia and requested that the tunnel fan be turned off the smell was terrible I don’t know what’s going on down there but the smell is the worst it’s ever been. I understand you have things in future for odour mitigation but I’m not willing to wait I think it is in order to get a mist deodorising machine working immediately. The rules clearly state no objectionable odour to cross the boundary and it is right up to my house please come back to me with the solution please. |
NW |
23.9 |
OFF |
Normal |
|
15/12/2023 |
15/12/2023 -16:21 pm |
Sewer smell bad again |
NW |
47.3 |
OFF |
Normal |
|
14/12/2023 |
14/12/2023 – 20:30 pm |
Complainant could smell plant up at his house . Requested the odour assessor to perform assessments in the evening |
NW |
34.9 |
OFF |
Normal |
|
5/11/2023 -9.55pm |
5/11/2023 - 9.55pm |
Smell |
NW |
20.8 |
Off (00:00 to 23:06) |
Normal |
|
1/11/2023 |
1/11/2023 |
Smell |
NNW |
16 |
Off |
Normal |
|
1/11/2023 |
31/10/2023 |
Smell |
ESE |
18.2 |
On (0:00 to 4:58) |
Normal |
|
1/11/2023 |
18/10/2023 |
Smell |
SE (0:00 to 8:35) |
15.1 |
On (0:00 to 8:35) |
Normal |
|
1/11/2023 |
14/10/2023 |
Smell |
NW |
45.6 |
Off |
Normal |
|
1/11/2023 |
13/10/2023 |
Smell |
NW |
32.9 |
Off |
Normal |
Wastewater Discharge Complaints
|
Date of Complaint reviewed by Wellington Water |
Date of Incident |
Complaint description/ Characteristics as per the complainant |
Duration of the alleged event/incident |
Location of the complaint |
Cause of the complaint |
Remedial actions undertaken |
|
10/04/2024 |
7/04/2024 |
On 7/04/2024, the complainant emailed Greater Wellington Regional Council regarding sewage from possibly Porirua Wastewater Treatment Plant going into the ocean near Rukutane point using the FB post uploaded on the Titahi Bay Residents Associations page as reference. |
The complaint indicated that there would have been another discharge incident on 7 April 2024. This is still under investigation. |
Lodged via Titahi Bay Residents Association's Facebook |
Visible discolouration around the coastal marine area and cause is still under investigation. |
Investigations underway to determine the cause. |
|
10/04/2024 |
6/04/2024 |
On 9/04/2024 at 6.20 pm, a formal complaint was lodged to Greater Wellington Regional Council. The formal complaint was lodged for the discharge captured through video for the discharge that occurred on Saturday 6 April 2024 from the Treatment Plant outlet pipe (600m from Titahi Bay beach). |
The discharge started at 2.17pm and lasted for approximately 2 hours and 21 minutes. |
Titahi Bay catchment site |
Visible discolouration around the coastal marine area and cause is still under investigation. |
Investigations underway to determine the cause. |