Why are improvements needed?
Wastewater from households throughout Taupo township is piped to the Taupo Wastewater Treatment Plant (TWWTP) located in Motutahae Street, Taupo. Here it is treated and pumped to the either the Rakanui Road or View Road Land Disposal areas where it is sprayed onto paddocks of special grass to grow haylage. This operation continues all year round.
The original Taupo Wastewater Treatment Plant in Motutahae Street was built in 1972, and although it has had minor improvements since that time, subsequent population growth has meant that volume of wastewater needing treatment nearly exceeds the amount that the Plant was designed to treat. Parts of the treatment plant are also beginning to age. However, it is financially impractical to build a new wastewater treatment plant on another site. Such a move would cost tens of millions of dollars just to reroute all the pipelines, let alone build a new treatment plant. Accordingly Council needs to improve the existing treatment plant.
Not only will this proposed upgrade enable the plant to cope with past and anticipated population growth and replace tired components, it will also enable Council to introduce new technologies into the treatment process, improving the quality of the treated wastewater. The upgrade may also enable the eventual closure of both Acacia Bay and Waitahanui treatment plants, which will have both financial and environmental benefits for Taupo residents.
What work will the upgrades include?
It is intended that a programme of improvements will be built between late 2009 and 2020. Various components will be expanded or replaced either as the older component reaches its intended operating life; or population growth is such that it reaches its operational capacity. The proposed structures are shown on the aerial photograph Pictorial staged layout of TWWTP
The anticipated time frame to build them is shown below:
Structure Expansion Phase & year of addition
|
Phase 1 - 2010 |
Third primary sedimentation tank, trickling filter tower 1, second thickener, third digester and UV disinfection |
|
Phase 2 - 2015 |
Trickling filter tower 2, second secondary clarifier and tertiary filtration |
|
Phase 3 - 2020 |
Fourth primary sedimentation tank and fourth digester |
|
Potential Effects of the Changes
Council is preparing further information on the effects of the proposed upgrade. This information will be posted here as it becomes available.
The boundaries of the wastewater treatment plant site will not change. While the final design of each of the above components cannot be precisely determined at this early stage, their dimensions and approximate location can be estimated at this time based on similar buildings in other locations. However, Council has undertaken to build and finish all the structures at the site so as to minimise their visual impacts on the surrounding area as much as practicable. Council has prepared a number of montages on how the new structures will look from a distance once landscaping has been completed. To view the montages click on the documents below
Further information on the effects of the proposed upgrade
Resource Consent Applications
Resource consent approval will be required from both Environment Waikato (EW) and Taupo District Council (Environmental Services) for different aspects of the upgrade.
When the WWTP first began operations consent approval was not required to create biogas on the site; or in respect to the plant’s potential to create odour. However, although the potential for odour has recently been reduced, Council has been advised that Consent approval from EW should still be sought under the current Regional Plan given that the plant’s existing use rights will cease in respect to these rules because of the upgrade. A resource consent application will be submitted to EW in late June/early July 2009.
Furthermore, Engineering staff will shortly prepare a resource consent application for Stage 1 of the upgrade with the Environmental Services Division of Council. District Plan matters addressed in the application will include proximity of structures within 25m of the river, network utility structures outside of the road reserve, and potentially earthworks and building size/location. A number of measures to avoid or mitigate any potential adverse effects from these District Plan infringements will be suggested in the application. Many of these mitigation measures have been the subject of the public consultation undertaken by Council in recent months.
The preparation of District Plan designation application (called a “Notice of Requirement”) for the whole wastewater treatment plant has been postponed until 2010.
Community Consultation & outcomes
In March 2009 Council undertook a mail drop in the urban area near the treatment plant advising of the upgrade, which included information and feedback forms about the upgrade. In early April Council also held two open days where the public were invited to meet staff in the old Taupo Library bus, either at the corner of Hindmarsh Drive and Stephensons Way; or at the corner of Rickit and Motutahae Streets. Over the two days about 30 people attended. Fourteen feedback forms were also received. The primary concerns identified through the consultation process include:
- Odour experiences and concerns
- Visual impacts
- Location of the wastewater plant in relation to existing and future housing/subdivision
- Noise.
In response to the odour and noise concerns Council researched and implemented a number of immediate actions which can help alleviate potential problems. These include:
- Installing a new biogas blower fans and silencers, and enclose them in a new noise attenuated room.
- Install acoustically lined internal walls, ceilings and sound curtains to help contain noise from machinery.
- Inspect and replace older pipework and associated lagging and fittings – particularly those sections of pipe that are pressurized and prone to vibration.
- Construct boxes around inlet pipes, manifolds and fittings that may still generate noise.
- Refurbish the “floating” roof / cap on the digesters to help reduce the likelihood of gases that may create odour from escaping.
- Revise the standard operating procedures / maintenance programmes.
The total cost of this work programme is in excess of $100,000. Other measures to mitigate odour or noise potential will be undertaken in Stage 1 of the upgrade in 2010.
A painting and planting programme has also commenced throughout the site to reduce the visual impact of existing and future structures.
Further Discussion
Should you want to discuss the proposed upgrade further with Council staff, please contact either John Davy on 07 376 0801 or Mark Day on 07 376 0638 between 8:00 am and 5:00 pm, Monday to Friday.