Tauranga City Council
Project Update: Te Maunga Waste Water Treatment Plant, Mt Maunganui
In 2016 Reaman Industries were contracted by the Tauranga City Council to replace the diffusers in the reactors of their existing waste water treatment plan in Mt Maunganui.
Shows the amount of sludge that had to be removed prior to lifting out of each aeration lateral. Once the sludge was removed and the air supply down-comer was disconnected the lateral was lifted out for cleaning and removal of the existing diffusers.
After the removal of the diffusers the lateral was cleaned and repaired on completion of that phase the new diffusers were fitted to the lateral, checked and awaited replacement back in the reactor.
Upon completion of all of the sludge from the bottom of the reactor, the completed laterals were reinstalled and installation completed – the photo shows installation prior to filling and testing.
Project Description: Te Maunga WWTP Upgrade 2005, Mt Maunganui
The Te Maunga Waste Water Treatment Plant (WWTP) provides wastewater treatment for the domestic, commercial and industrial communities from the Mount Maunganui and Papamoa catchments. The WWTP is located south of Tauranga and was commissioned during 1996. The first upgrade took place in the year 2000, which entailed modifications to the aeration control and distribution system and the installation of additional diffusers. The plant was designed as an extended aeration activated sludge system, utilising an oxidation ditch configuration.
The modifications to the bioreactor and the provision of additional aeration capacities resulted in doubling the organic and hydraulic capacity of the existing plant (from 8,000 m3/d to 16,000 m3/d) and controlling nitrogen removal more effectively.
The design of the aeration system was critical to ensure that minimal disruptions and downtime occurred during the removal of the existing ceramic diffusers and the installation of new banks of diffusers. Divers were used to install brackets on the tank floor. Tube type silicon membrane diffusers were installed in all the aeration zones. The banks of diffusers are removable and can be lifted out of the tanks using a 50-tonne crane.
The removal of the existing diffusers, the installation of the new banks of diffusers and the connection and extension of the existing pipe header had to be carried out progressively, to ensure continued treatment of the incoming wastewater.
This project was completed on time and under budget including:
- 20% overall site power saving, which equates to at least 30% power saving on the aeration system as reflected in lower airflow requirements
- Lower utilisation of blowers which means longer life expectancy
- Doubling the treatment capacity from 32,000 EP to 64,000 EP
Te Maunga WWTP Stage 2 upgrade