Moa Point Wastewater Treatment Plant
At the Moa Point Treatment Plant, sewage travels through a series of screens, tanks, bioreactors, clarifiers and ultraviolet treatments before being discharged as liquid into Cook Strait.
It was granted new consents on 11 May 2009. These consents will continue for 25 years (expire 11 May 2034).
In general, the consents allow WCC:
- to continuously discharge up to 260,000 cubic meters per day of treated and disinfected wastewater into the coastal marine area via an existing submarine outfall,
- to discharge up to 4500 litres per second of mixed disinfected, treated and milli-screened wastewater to the coastal marine area during and/or immediately after heavy rainfall, when the quantity of wastewater arriving at the Moa Point Wastewater Treatment Plant exceeds 3000 litres per second,
- to occupy the foreshore and seabed of the coastal marine area with an existing submarine outfall pipeline,
- to continuously discharge contaminants (including odour) to air from the Moa Point Wastewater Treatment Plant ventilation system.
Resource consents
WGN080003 [26182] Land Occupation by Outfall Pipe (Moa Point WWTP)
WGN080003 [26183] Contaminants Discharge to Air WWTP (Moa Point WWTP)
WGN080003 [31505] Discharge of Treated Wastewater to Coastal Marine Area (Moa Point WWTP)
WGN080003 [35047] Discharge of Partially Treated Wastewater to Coastal Marine Area (Moa Point WWTP)
WGN960094 [1471] Contaminants Discharge to Air IPS (Moa Point WWTP)
Resource consent reports
Annual Reports:
Moa Point Wastewater Treatment Plant Annual Resource Consents 2020/2021
Moa Point Wastewater Treatment Plant Annual Resource Consents 2019/2020
Careys Gully Southern Landfill Annual Resource Consents Report 2021/2022
Moa Point Wastewater Treatment Plant Annual Resource Consents Report 2021/2022
Moa Point Wastewater Treatment Plant January March 2023 Quarterly Resource Consents Report
Moa Point Wastewater Treatment Plant FY2022 23 Annual Resource Consents Report 1
Moa Point Wastewater Treatment Plant, GWRC Compliance Monitoring Report 2022 - 2023
Plant performance
Current Status: Non-compliant
Period: May 2024
Commentary:
The plant remains non-compliant for suspended solids, faecal coliforms and Biochemical Oxygen Demand (BOD) (all 90-day, 90th percentile limits). Steps to fix this are being undertaken, however, breakdowns at the plant are impacting a return to compliance. The return to three operating clarifiers in July is expected to improve treatment processes.
Discharges:
On May 1st, untreated wastewater was released into Tarakena Bay because of heavy rain and the reduced pumping capacity of the Inlet Pump Station (IPS) due to the IPS renewal project.
Odour:
There were 16 odour complaints relating to the Southern Landfill site and Careys Gully Sludge Dewatering plant. None were assessed to be offensive and objectionable by GWRC.
Items of significance:
Clarifier #2 Renewal Project
The mechanical repairs to the clarifier, including corrosion protection of the structural components has progressed well and is expected to be completed early June. The next step is to replace the major mechanical components including the main bearing. The clarifier should be back in operation by July 12th.
Inlet Pump Station (IPS) Project
The two new riser pipes have been successfully installed and the wet well is back in service. Four out of 10 riser pipes still need to be replaced and this is planned for early 2025.
Advisory Notice issued
Greater Wellington Regional Council issued an advisory notice to Wellington Water for the sludge carry over discharge via the long outfall pipeline that occurred on 23 January.