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 2023-2024
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 FY2022 23 Annual Resource Consents Report 1
Moa Point Wastewater Treatment Plant, GWRC Compliance Monitoring Report 2022 - 2023
Quarterly Reports
Moa Point Wastewater Treatment Plant July - September 2024 - Quarterly Resource Consents Report
Moa Point Wastewater Treatment Plant January March 2023 Quarterly Resource Consents Report
Appendices
Moa Point Waste Water Treatment Plant Annual Resource Consent 2023/2024 - Appendices
Plant performance
Current Status: Non-compliant
Period: November 2024
Commentary
The plant remains non-compliant for suspended solids (90th percentile limit) and faecal coliforms (90-day geomean and 90th percentile limits). The current daily results for suspended solids are trending back into compliance by end of December for both the 90-day geomean and 90th percentile limits. Daily results for faecal coliforms show occasional spikes in results which is affecting the 90-day geomean and 90th percentile limits and continues to be investigated.
Discharges
There was one unconsented wet weather discharge via the short outfall on 15 November due to the reduced pumping capacity of the Inlet Pumping Station, whilst the riser pipe renewal project takes place (see items of significance).
Odour
There were two odour complaints in November. One relating to Moa Point, the other relating to the Southern Landfill site and Careys Gully Sludge Dewatering plant.
Items of significance:
Clarifier #1 Renewal Project
Physical works have begun to replace the main bearing and renew structural elements on the final clarifier. With only two of the three clarifiers in operation, pumping capacity is reduced. Work is being carried out over the summer/autumn months when effluent flows are expected to be lower. The project is expected to be completed by mid-2025.
Inlet Pump Station (IPS) Project
Physical works for the third and final phase of the IPS project are progressing well and is on target for completion by March 2025. This involves replacing the remaining four of 10 riser pipes, along with four of the 10 submersible pumps, strengthening the IPS’s resilience for high rainfall events.