Christchurch City Council needs to upgrade Akaroa’s wastewater system. The upgrade reflects our commitment to ensure the Akaroa community is provided with a high quality wastewater system.
A new site has been chosen for technical and operational reasons, and recognises the historical importance of the Takapūneke Historic Reserve, where the current plant is located.
The new plant will be a compact modern facility, making use of recent improvements in wastewater treatment and attractively landscaped to limit visual impact. It will be quiet and will not cause odour. This will minimise the new plant’s impact on the environment and the community.
Please email the project team if you have any questions or would like to sign up for our project e-newsletter.
In June 2017, the flow meter at the Akaroa wastewater treatment plant was found to be faulty. The flow data from the flow meter had been used in the design of the Akaroa wastewater scheme and for the reuse and disposal options. New flow meters were installed and the data from these shows that the flow is much higher than previously thought. Due to seasonal variations in visitor numbers, flow data will continue to be gathered over summer and new design flows will be determined in March 2018.
In addition to the areas previously considered for irrigation of treated wastewater to land, two new areas are being considered (Redcliffe Point and Hickory Bay). Deep well injection is also being considered and more work is being done on non-potable reuse. Work to reduce groundwater infiltration and stormwater inflow into the wastewater network is also underway.
A briefing to the Banks Peninsula Community Board on the Akaroa Wastewater Scheme was given on 30 October 2017 [PDF, 327 KB]. The community board decided to reconvene the Akaroa Treated Wastewater Working Party to consider reuse options in light of the new flow data.
The Environment Court has granted an extension to the appeal and a progress report needs to be provided to the court by 25 May 2018. The Council expects to consult on options in July/August 2018 and hopes to make a decision on which option to pursue by the end of 2018.
The Council has obtained resource consents for building and operating the new Akaroa Wastewater Treatment Plant on Old Coach Road and a new pump station in the boat park at Childrens Bay, and for upgrading wastewater mains and the three existing pump stations. However, the Council's applications for consents to construct a new pipe outfall to Akaroa Harbour, and discharge treated wastewater via that pipe outfall, were declined, on the grounds that the discharge was offensive to Ngāi Tahu and because the Hearing Commissioners considered that alternatives to the discharge to the harbour had not been adequately investigated. For more information, view the Decision of the Hearings Commissioners(external link).
The Council has lodged an appeal against the decline of those consents but will not be making a decision on pursuing that appeal until it has reassessed alternatives for the discharge.
Lincoln University conducted a lysimeter trial where treated wastewater from the Duvauchelle wastewater treatment plant was irrigated onto soil cores taken from the golf course at Duvauchelle and the Takamatua Peninsula.
Lincoln University is also conducting a trial where various native plant species are irrigated using treated wastewater from the Duvauchelle wastewater treatment plant.
The key findings were that wastewater irrigation enhanced pasture growth and tree growth, that treated wastewater could be applied at a rate of 500–800mm per year and that nitrogen leaching was negligible compared to that from grazed pasture.
Consultation has closed on the options for the beneficial reuse, treatment and disposal of treated wastewater from Akaroa. As the flow data on which the options were based is incorrect, there will not be a Council hearing on these options. The consultation booklet [PDF, 15 MB] summarised the options that were considered:
For the detailed information about the options being consulted on, please refer to the report Akaroa Wastewater Investigation of Alternative Sites for Land Irrigation (CH2M Beca, March 2017) [PDF, 4.2 MB] and its appendices:
At the meeting on Monday 30 January, the Banks Peninsula Community Board received a Community Strategy Toward an Acceptable Solution to the Disposal of Akaroa Wastewater, prepared and adopted by the community of Robinsons Bay and adopted by Friends of Banks Peninsula. This included a request that Council takes a collaborative approach with the community on this project and that public consultation is delayed until April to allow this to occur.
In response to this, the Board resolved to establish a Working Party to collaborate with the community and engage on community concerns about the Akaroa Treated Wastewater Disposal Project, and to delay any further consultation on the project until April 2017.
The Community Board prepared terms of reference for the working party [PDF, 32 KB]. The notes from each of the working party's meetings are as follows:
The working party prepared a joint statement [PDF, 2.9 MB] summarising matters the working party members agreed and disagreed on. On 30 October 2017 the Banks Peninsula Community Board resolved to reconvene the working party to consider options in light of the new flow data.
The Akaroa Wastewater Technical Experts Group consists of experts working for the Council, the Friends of Banks Peninsula and Ngāi Tahu.
The terms of reference for the Akaroa Wastewater Technical Experts Group [PDF, 27 KB], their first joint statement [PDF, 88 KB], second joint statement [PDF, 197 KB] and third joint statement [PDF, 1.1 MB] are available.
The Council has been working with Ōnuku Rūnanga, Wairewa Rūnanga, the Akaroa Taiāpure Management Committee and Te Runanga o Ngāi Tahu (the Ngāi Tahu parties) and the community to explore land-based alternatives to the harbour outfall.
In 2016 the Council considered six options for disposal of treated wastewater:
A desktop study was undertaken in May 2016 to identify possible areas for land treatment options. The following criteria were used:
All of the areas identified as possibly suitable for irrigation were on Takamātua Peninsula or in the Takamātua Valley and are in private ownership. Options for access to the needed land are purchase, lease or license. Several of the options required discharge of remaining wastewater in a diffuse way on the coastline, most likely via a coastal infiltration gallery at the end of the Takamātua Peninsula.
Ngāi Tahu strongly supports the options of year-round irrigation to trees and pasture, as they are consistent with their cultural values. The options involving a diffuse coastal discharge were not supported by Ngāi Tahu, as they do not use natural processes to restore the mauri of the wastewater, and continues discharge of it into the harbour. View the Akaroa Treated Wastewater Disposal Options Consultation Booklet [PDF, 1.2 MB] for a description of each of the options that were considered in 2016, and their advantages and disadvantages.
For more detailed information on each of the options considered in 2016, please see the Akaroa Wastewater Concept Design Report for Alternatives to Harbour Outfall (CH2M Beca, May 2016 [PDF, 3.8 MB]) and the appendices to the report:
The Council sought public feedback on these options between 26 April and 12 June 2016. View the questions and answers from the consultation meetings, and the submissions and project team responses:
Following the public consultation, the Council commissioned preliminary geotechnical investigations, including test pits and infiltration testing on some of the possible irrigation sites at the end of May 2016, and a cover letter [PDF, 1.7 MB] and two reports were received (see appendices A and B of the CH2M Beca report below for the reports). The cover letter highlighted the risk of exacerbating instability where the slopes downhill of the irrigation area are steeper than 15 degrees, and their recommendation was that we avoid irrigating those areas.
These land investigations found that Takamatua Peninsula and Blocks F and H are not suitable for irrigation of treated wastewater and so the Council is no longer considering these locations. This meant that there was a risk that insufficient land would be available for irrigation and so the Council decided to consider land that may be suitable for irrigation further afield. The areas that met the revised criteria in the wider area were Takamatua Valley, Robinsons Bay and Pompeys Pillar.
Options 3 to 5, which included a wetland or infiltration basins and a coastal infiltration gallery on the headland of Takamātua Peninsula, were not supported by the community or the Ngāi Tahu parties, so the Council is not considering these options further until land based options have been more fully investigated.