We are upgrading Akaroa’s wastewater system. The wastewater treatment plant was built in the early 1960s at Takapūneke and is in a historically and culturally sensitive place.

A hearings panel recommendation to develop a new system, where highly treated wastewater from Akaroa will be used to irrigate new areas of native trees at Robinsons Bay, Takamātua and Hammond Point, and to irrigate public parks and flush public toilets, was accepted by Council on 10 December 2020.

Next steps

Work is underway in Akaroa to reduce the inflow and infiltration of groundwater and stormwater to the wastewater network. This additional water enters the system through leaky pipes and connections and illegally installed drains on some properties. The target is to reduce the groundwater and stormwater flowing through the wastewater system from 60 per cent to 20 per cent.

The project team will be focusing on the technical work needed to submit a resource consent application for the new scheme, including an assessment of its environmental effects. The team will also work on securing the land needed for the project, and to establish the community reference group, which will comprise people with expertise relevant to the project.     

Latest news

See Newsline: Council approves Inner Bays for treated wastewater scheme(external link).

To keep up with the latest news on the project please sign up for our Akaroa wastewater project newsletter.(external link)

We have consents to build a new wastewater treatment plant on Old Coach Road and a new pump station at the Childrens Bay boat park.

The new plant will be modern and compact, using the latest methods of treatment. It will be quiet, odourless and attractively landscaped. All wastewater leaving the plant will be highly treated.

The following is the wording of the Council resolution supporting the Inner Bays Irrigation Scheme option, passed on 10 December 2020.

The Council:

  1. Acknowledges that many submitters advocated for a sustainable development approach to water in Akaroa and that the Council recognises the value of water as a precious resource and taonga.
  2. Acknowledges that the water supply in the Akaroa area and wider Banks Peninsula will be increasingly under threat as climate change increases and that working towards non-potable reuse is supported by the Hearings Panel and most submitters.
  3. Acknowledges the concerns of the community about the poor state of the wastewater network and recommends that the Council aims for less than 20% inflow and infiltration through its work on the Council network and that it also requires private property owners to repair their pipes.
  4. Increases the promotion of water conservation measures in Akaroa to reduce the volume of wastewater, including the use of Smart Meters funded as part of the Three Waters Reform funding and notes the support by the Hearings Panel and some submitters for excess water charges to assist with this.
  5. Regularly communicates progress on the repairs and of conservation measures to the community, Community Board and the Council and that the name of the project change to the Akaroa Reclaimed Water Treatment and Reuse Scheme.
  6. Requests Council Officers to work with the Community Board to establish a Community Reference Group including members from the local Rūnanga to ensure that community concerns about the approved Akaroa Reclaimed Water Treatment and Reuse Scheme are listened to and, where possible, addressed.

In response to question one of the Akaroa Treated Wastewater Options consultation document, 'should we discharge highly treated wastewater from our new treatment plant to land or should we continue to discharge into Akaroa Harbour?'

That the Council:

  1. Rejects that Akaroa’s highly treated wastewater is discharged from the new treatment plant to the Akaroa Harbour.
  2. Approves that Akaroa’s highly treated wastewater is discharged from the new treatment plant to the land.

In response to question two of the Akaroa Treated Wastewater Options consultation document, 'if it decides to develop a scheme where highly treated wastewater is used on land for irrigation, where would you prefer the Council to irrigate? Inner Bays (Robinsons Bay, Hammond Point, Takamātua), Goughs Bay or Pompeys Pillar?'

That the Council:

  1. Approves that Akaroa’s highly treated wastewater is used on land for irrigation at Inner Bays (Robinsons Bay, Hammond Point, Takamātua)
  2. Requests Council Officers to investigate and incorporate where practical the following into detailed design of the scheme:
  3. additional wetland site options as part of the detailed design, with the goal of reducing the size of the storage ponds.
  4. maximize the planted areas of native bush to both reduce the size of the ponds and increase biodiversity outcomes.
  5. investigate additional areas for irrigation of public space within the Akaroa catchment with the goal of increasing non-potable use.
  6. futureproofing for potential non-potable reuse.
  7. the re-use of the current UV treatment unit in the new treatment plant to enable non-potable reuse.
  8. native tree plantings in Robinsons Bay to avoid key archaeological sites as recommended in the Heritage New Zealand submission and installation of interpretation signage for visitors to the site.
  9. softening the contours of the plantings by following the natural contours of the land, running down gullies where possible and raised boardwalks where appropriate for recreation in new wetland areas.
  10. Notes that water conservation and Inflow and Infiltration reduction measures aim to reduce the size of the pond.
  11. Requests that Council Officers investigate the use of storage tanks instead of storage ponds and if practical discuss the option with the Community Reference Group.
  12. Requests Council Officers to investigate and report back to the Council on the option of a scheme for local employment for the planting and maintenance of the native trees. In response to question three of the Akaroa Treated Wastewater Options consultation document, 'would you support us irrigating public parks in Akaroa with highly treated wastewater?'

That the Council:

  1. Approves irrigating public parks and flushing public toilets in Akaroa with highly treated wastewater as part of the scheme.

In response to question four of the Akaroa Treated Wastewater Options consultation document, 'would you like use to explore the feasibility of a purple pipe scheme for Akaroa, so that residential property owners could use the water for garden watering and other nondrinking purposes?'

That the Council:

  1. Supports and requests Council Officers to explore the feasibility of a non-potable reuse (purple pipe) scheme for Akaroa, so that property owners could use the water for garden watering and other non-drinking purposes.
  2. Requests Council Officers work with the Ministry of Health, the Canterbury District Health Board, Ngāi Tahu and water suppliers that are interested in non-potable reuse to develop non-potable re-use guidelines or standards for New Zealand.
  3. Requests Council Officers discuss options for enabling non-potable reuse of treated wastewater with the Council as soon as practicable, should the regulatory framework change.

That the Council:

  1. Includes consideration of additional budget in the draft Long Term Plan 2021-2031 to implement the approved Akaroa Reclaimed Water Treatment and Reuse Scheme.

Moved: Councillor Templeton

Seconded: Councillor Coker

Carried

(Councillors Chu, Gough and MacDonald requested that their votes against the resolutions be recorded).

  • The scheme recognises the historic and cultural importance of Takapūneke Historic Reserve to all New Zealanders and particularly to Ngāi Tahu.
  • The modern plant will produce extremely clean treated wastewater, which will be used for watering public parks and flushing public toilets. The aim is to use it as a non-potable water supply for residents and businesses once the required regulations are in place.
  • The plant contributes to higher water quality that supports water sports, recreation, tourism and aquaculture in the region.
  • The new site is closer to more potentially suitable land for irrigation.
  • The frequency of untreated wastewater overflows from the network will greatly reduce.

  • New areas of native bush and wetland will enhance biodiversity.

In 2015 we 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, our 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).

In May 2019, we decided to drop our appeal against the decline of those consents. For more information, view the Newsline article(external link).

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. 

The University of Canterbury 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. 

A lysimeter experiment and field trial to determine options for the beneficial reuse of wastewater from Duvauchelle and Akaroa, Banks Peninsula, June 2017 [PDF, 1.6 MB]

A field trial to determine the effect of the land application of treated municipal wastewater onto selected NZ-native plants on Banks Peninsula, September 2020(external link)

For more information see the Kiwi Science webpage(external link).

The Ngāi Tahu parties had a significant role in preparing the consultation document and prepared a joint statement in June 2020 on the options. The Ngāi Tahu parties comprise Ōnuku Rūnanga, Te Rūnanga o Koukourarata, Wairewa Rūnanga, the Akaroa Taiāpure Management Committee and Te Rūnanga o Ngāi Tahu.

Read the Ngāi Tahu Parties joint statement(external link).

At the meeting on 30 January 2017, 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 the Council takes a collaborative approach with the community on this project.

In response to this, the Board resolved to establish a Working Party to collaborate with the community and engage on community concerns about the project.

The working party had a significant role in preparing the consultation document and prepared a joint statement in June 2020 on the three land-based options. As its work was complete, it was dissolved just before consultation began in July 2020.

Read the full joint statement.(external link)

The following information relates to earlier options, investigations, consultations, consents and the new treatment plant.

2017 – Consultation on reuse, treatment and disposal options – 3 April 2017 to 8 May 2017

Consultation took place 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, 1.4 MB] summarised the options that were considered:

  1. Irrigation of trees or pasture in Robinsons Bay.
  2. Irrigation of trees or pasture at Pompeys Pillar.
  3. Irrigation of trees or pasture in Takamātua Valley, in combination with another area.
  4. Non-potable re-use in Akaroa, in combination with another option.
  5. Disposal via a new outfall pipeline to the mid-harbour (the original proposal for which consent was sought).

For the detailed information about the options 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:

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 in July 2017 and the data from these shows that the flow is much higher than previously thought. Data from these new flow meters is being used for design. 

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.

A public meeting was held in the Gaiety Hall in Akaroa on 4 April 2018 to update the community about what has been happening on the project over the previous few months and to introduce a new option of deep bore injection that is being considered. Two presentations were given:

2016 –Six options

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:

  1. Year-round irrigation to trees.
  2. Year-round irrigation to pasture.
  3. Summer-only irrigation, with a wetland or infiltration basin and discharge via a coastal infiltration gallery at other times.
  4. Subsurface flow wetland and discharge via a coastal infiltration gallery.
  5. Infiltration basin and discharge via a coastal infiltration gallery.
  6. Outfall pipeline to the mid-harbour (being the one applied for).

A desktop study was undertaken in May 2016 to identify possible areas for land treatment options. The following criteria were used:

  • not too far from the new wastewater treatment plant on Old Coach Road (a two kilometre radius was used), relatively flat (less than 15 degree slope)
  • at least 25 metres from a residential area or waterway
  • property size of at least 1 hectare
  • not known to have land stability issues.

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.

Consultation meetings November to December 2016

A public meeting was held at the Gaiety Hall on Wednesday 9 November 2016 and a presentation [PDF, 4.9 MB]was given to explain why the Council is exploring alternatives to a harbour outfall for treated wastewater disposal, how these three areas were selected, and to provide the results of land investigations for areas that may be suitable for irrigation of treated wastewater.  View the questions raised at the meeting and the answers from the project team [PDF, 95 KB] [PDF 96KB] and responses to questions tabled at the meeting by the Robinsons Bay community [PDF, 174 KB].

A community consultation workshop was held at the Gaiety Hall on Saturday 3 December 2016.  The community provided responses to four questions; see below for photos of these responses:

For further background information, there are also three historical reports that explored wastewater options for Akaroa:

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 proposed scheme in the consent application included:

  • replacing the existing trunk pipelines, upgrading the existing pump stations, and constructing a new terminal pump station to pump flows to the new treatment plant
  • a terminal pump station to be located in the Akaroa boat/trailer park, which will incorporate fine screens and grit removal, to protect the progressive cavity pumps and to provide primary treatment
  • a new biological nitrogen removal (BNR) membrane wastewater treatment plant located at the site on Old Coach Road, providing a higher quality treated wastewater. The treatment process will likely be the Modified Ludsak-Ettinger (MLE) process, although other alternatives proposed by tenderers will be considered. Solids separation and disinfection will be provided by membrane filtration. High flows will bypass the main treatment process, and will receive ultraviolet (UV) disinfection before being discharged into the outfall pipe. The design of the treatment plant has taken into account the seasonal population by including two parallel treatment trains so that capacity can be increased as needed during peak summer flows, and has been designed to provide full treatment for the peak summer population in 2041. Note that bypass treatment is no longer proposed and that all wastewater will receive full treatment
  • a new polyethylene discharge pipeline along Old Coach Road Treated to the start of a new harbour outfall at Childrens Bay, so that treated wastewater could flow by gravity from the new treatment plant to the outfall
  • a new 2.5km long polyethylene (PE) harbour outfall pipe extending from Childrens Bay, with a diffuser located at 9.5m depth
  • decommissioning the existing wastewater treatment plant on the Takapūneke Historic Reserve.

The whole project was estimated in 2014 to cost about $35 million, including the new treatment plant, new harbour outfall, new terminal pump station and upgrades to the existing pump stations and pipeline that runs through Akaroa.

The project, consent process, harbour outfall and possible effects 

Consents

The resource consent for discharge from the existing treatment plant to the harbour was renewed 2013 for seven years, to allow time to get all the consents for the new plant and to build it. The resource consents for the Akaroa wastewater scheme were lodged in June 2014, as required by the consent for the existing discharge. The consent hearing was completed in May 2015 and the Hearing Commissioners' decision was received in July 2015.

Consents were granted for the wastewater treatment plant, terminal pump station and reticulation, but not for wastewater discharge from the harbour outfall and other associated consents. The Council lodged an appeal to the Environment Court, and the Ngāi Tahu parties joined that appeal. The appeal has since been withdrawn. See the Newsline article(external link)(external link) for more information.  The full consent application and appendices are:

Why the treatment plant is being moved

The current Akaroa wastewater treatment plant is located at Takapūneke Historic Reserve. In 1830, Te Rauparaha, with the help of the captain of the British Ship the brig Elizabeth, captured the Rangatira (chief) of the maori pa, Te Miharanui, and massacred up to 200 of his people on the site.

It is now widely acknowledged that construction of a wastewater treatment plant at this site was an act of particular cultural insensitivity. The Council now recognises the area as an historic reserve, and hopes the site will become a National Reserve, in recognition of its significance.

The Council worked in partnership with Ōnuku Rūnanga to develop the Takapūneke Reserve Management Plan.

The location of the new treatment plant

In December 2011, the Council accepted recommendations from the Akaroa Community Wastewater Working Party and Akaroa/Wairewa Community Board, which reviewed different options for future wastewater treatment and the location of a new plant.

The working party recommended two general locations for the plant – one north of Akaroa and one to the south. The northern site was chosen in October 2012 as it was closer to areas that may be used for irrigating treated wastewater in the future, is closer to Akaroa where reclaimed water could possibly be used in home gardens or toilets, and had better road access and power supply than other sites that were considered. This site was supported by Ōnuku Rūnanga.

The Council has purchased land at the top end of Old Coach Road for the new treatment plant site. Landowners of all suitable sites in the Akaroa vicinity were approached with the offer to negotiate a sale, and only one to the north of Akaroa agreed to do so.

 

Appearance

The treatment plant will include concrete tanks, and a building to house noisy equipment (e.g. pumps) and the membrane filters. The tanks and equipment buildings for the treatment plant will have a very small footprint (approximately 65 m by 20 m) on this small (approximately 1 hectare) site. To minimise the height of the plant, some of the tanks will be partially sunk into the ground. All surrounding areas of the plant will be extensively landscaped with native plants grown from seeds sourced from nearby bush. This will include tall evergreen trees to screen the treatment plant and ensure visibility from Akaroa and Old Coach Road is reduced as much as possible. The plant will be set back into the hillside.

A new pump station will be needed in Akaroa to pump wastewater to the treatment plant. This will be located in the car/boat park next to Childrens Bay, backing onto the mini golf course. The pumping station will also include fine screens and a grit removal system to remove solids from the incoming wastewater before it is pumped up the hill to the treatment plant for further treatment and disinfection. The terminal pump station will be in a building. Landscaping around the terminal pump station will eventually mostly obscure it from view.

Noise

Wastewater treatment plants do have some noisy machinery but this equipment will be inside a concrete building. The treatment plant will meet the noise limits in the Christchurch District Plan, and the nearest house is 250 metres away. The terminal pump station will also be designed to meet the noise limits in the Christchurch District Plan, and to minimise noise as much as possible for the neighbouring mini golf course. There should be no disturbance to any nearby residents.

There will be some noise during construction due to the heavy machinery needed for construction. To minimise the effects of noise, construction work will be generally limited to Monday to Saturday 6:30am to 8:00pm, with no work on Sundays or public holidays. Some work outside of these hours may be necessary to avoid significant disruption to traffic or for contractor and public health and safety reasons (e.g. for sewer connections when flow is typically lower (at night) to limit risk of overflows, or in areas where excavations cannot be left open and is not practicable to temporarily fill in) or for environmental reasons (e.g. to enable critical construction works in relation to stream and groundwater levels due to the tide and a forecast of severe weather). Neighbours to the works will be advised in writing in advance and noise and vibration will be minimised as far as practical.

Odour

Modern wastewater treatment plants don’t produce any offensive or objectionable odours under normal operating conditions. The parts of the treatment plant that can be odorous will be covered and the air extracted and passed through a biofilter to treat the odour. The terminal pump station will be in a building and the air from this will also be extracted and passed through a biofilter to treat the odour. Contingency plans will be developed to deal with any adverse effects if there is a plant breakdown.