What alternative waste-management options were considered?

The Council considered the following alternatives to landfilling as part of the assessment:

Option 1: Closure of the existing Southern Landfill

Option 2: Closure of the existing Landfill and continued operation of the transfer station

Option 3: Extension of the existing Landfill

Option 4: Conventional (mass burn) incineration

Option 5: Advanced thermal treatment

  1. Gasification

  2. Pyrolysis

Option 6: Mechanical heat treatment

Option 7: Mechanical biological treatment.

How did you assess the alternatives?

The Council asked the community to rank the values below in terms of importance, 1 being the most important and 5 being the least important.

  • Environmental

  • Community impacts/values

  • Technology risks

  • Product risks

  • Legislative/Resource Management Act risks

  • Financial.

Community feedback was combined with Council priorities to create an overall weighting (a measure of importance) for each value. This ensured that any weighting used for the assessment would be robust, holistic and balanced and the results would not be skewed towards one particular segment of the community. 

Once the weighting for each value in the assessment was finalised, a waste expert from Tonkin + Taylor was commissioned to score each individual value for each alternative.

Once the assessment was completed, the results of the assessment were presented to Council’s project team to review the score of each value and the reasons the score was given. Any score changes and reasons for the changes during this review process were noted. This ensured that the process remained transparent.


What were the results of the assessment?

Based on the assessment, option 3: extension of the existing Landfill was deemed the most viable option. This was followed closely by option 1: closure of the existing Landfill and then option 2: closure of the existing Landfill and continued operation of the transfer station.

There was a big gap between options 1-3 and options 4-7 due to the inherent risks of the alternatives and the anticipated cost and scale of these alternatives.


The assessment resulted in the extension of the Southern Landfill as the most viable interim solution. How do I know if this assessment was done appropriately and was not just a token gesture?

Council’s waste operation officers are constantly monitoring new developments in the waste sector, particularly in a New Zealand context. As part of the Southern Landfill proposed extension project, we have consistently maintained that extending the Landfill is likely to be the most viable interim solution for waste management for Wellingtonians.

However, in this fast-changing time of technical developments we needed to check that our assumptions were correct and assess the other alternatives.

The project team adopted an unbiased and transparent process, remaining open-minded about what the next steps would be if the results differed from what was anticipated.

During our first engagement process we were pleased to see how passionate the community was about waste disposal, particularly its effects on Ōwhiro Stream, the general environment, traffic and climate change.

We also learned that some communities perceived how we operated differently from how we perceived ourselves. We have already made some changes to our operations as a direct result of this feedback, particularly around preventing litter from the Southern Landfill getting into Ōwhiro Stream.

We are committed to ensuring that community concerns are kept at the forefront of any concept design for and management of the Landfill extension.


What opportunities was the community given to provide feedback on the values?

We held several public information sessions and an online Facebook Q&A session in late September and early October.

Background information on what each alternative meant and what each value covered was available online and at the information sessions. We also had an online survey on Council’s Let’s Talk website to provide another opportunity for feedback. The online survey and information sessions were promoted through the Council website and various online platforms, i.e. Facebook, Twitter and Instagram.

People could fill in scorecards at the information sessions, complete the online survey or provide their feedback via Facebook. This engagement period went from 29 September to 14 October. We collated the feedback and fed this into the alternatives’ assessment.


The Council just declared a climate emergency but the expansion of the Southern Landfill being the most viable solution seems contradictory to this. Aren't you being hypocritical?

The goal of the assessment was to assess the most viable waste-disposal solution considering current government policies, existing regulations, financial impacts, current community values, existing environmental standards, existing technology and the products of each disposal method, as they stand today. This ensures that public funds will be spent wisely towards a credible solution rather than speculatively.

While the extension of the Southern Landfill came through the assessment as the most viable solution, it does not mean it will always be the optimum solution. We are committed to keeping up to date with changes in waste-management techniques, particularly in the New Zealand context, and should viable solutions arise we will explore those opportunities.

Over time, we anticipate that the declaration of a climate emergency will prompt all New Zealanders to shift their attitudes towards waste and the environment, providing government agencies with the mandate to change and set policies conducive to alternatives to landfilling.

We will ensure that the Landfill extension we design is flexible enough to accommodate any changes that may come with the viability of alternative waste disposal options.

I live close to the Southern Landfill and it affects me more than it does other Wellingtonians. Surely my views on it should have a greater bearing on the outcome?

Absolutely. The assessment was geared to take into consideration more localised effects rather than city-wide effects.

We worked to get most of our immediate neighbours, the Brooklyn and Ōwhiro Bay communities, involved by having local information sessions. A large majority of the public surveys received were completed by members of the local community. By design, this meant that the views of the local community heavily influenced the weighting for the assessment.

This feedback from the local community will be used to guide the extension design and subsequent operational principles going forward.


Did Council consider the future impacts, both environmentally and in the costs of maintenance, once the Landfill is closed as part of the assessment?

Our current cost model includes all costs for after-care of the Landfill upon closure, so yes, the costs have been included as part of the assessment.


Why not close the Landfill given that the first three options scored similarly?

The reason for extending the Landfill coming out on top was its high score in all aspects, but particularly cost.

Costs are higher for closing the Landfill (or just keeping the transfer station open) due to the costs of transporting and landfilling 15,000 tonnes per year of biosolids elsewhere, and the loss of generated revenue (currently used for offsetting rates and supporting Council’s waste-minimisation efforts).


Why do we need to consider this?

The existing stage of the Landfill will be full in approximately four years. Our resource consent for the current stage of the Landfill will expire in April 2026. Wellingtonians are invited to join the conversation on how we manage the waste, sewage and contaminated material of our growing city. 

Why did you start this process so late?

The Council applied for consent to extend the Landfill in 2013. The concept looked at starting filling at the top of Careys Gulley and then landfilling down to meet the existing fill site. This committed the whole valley to landfilling. The consent application was publicly notified and received submissions opposing the mainly top-down filling concept. We then placed the consent application on hold. 

We were optimistic that legislative changes, the economics and technological advancements allowing alternatives to landfilling to be viable in New Zealand would take place before we reached the deadline to make a decision on this.


What about alternatives to landfilling?

We have always kept an open mind on alternatives to landfilling by keeping up to date with emerging and existing technology and trends in waste-management solutions in New Zealand. 

All current alternatives still produce some form of waste, albeit in smaller quantities but with higher concentrations of pollutants that ultimately require landfilling.

Currently we think that technological limits, the legislative environment, public attitudes to waste and commercial realities make it too risky to apply any landfilling alternatives in New Zealand. We believe that alternatives are probably still a decade away and that landfilling is still the most appropriate option for now.

We need to test this assumption with a robust assessment of the viability of other alternative waste-disposal options. The alternatives include closing the Landfill, building a waste-to-energy plant or using biological processes.

All options will be tested by scoring against a set of concerns/values.  We will be engaging the community to understand which concerns/values are most important. The results of this assessment will allow us to check if we are going down the right path.

Looking forward, we believe that things will change and landfilling will no longer be the most appropriate option in the future. It is unfortunate that our consent expires at the cusp of a change in the way we think about waste; we believe that if landfilling is still the most viable solution, it will only be an interim step towards a future without landfills. 

How does this fit with our climate emergency or goal to be a zero carbon capital?

Nationwide, waste produces approximately 5% of New Zealand’s carbon emissions. In 2016, 89% of carbon emissions came from agriculture, energy production and transport.

From a waste point of view, we will need to change how we live, how we behave as consumers and how we view and treat the waste we produce to achieve our ambitions as a city.

This will take a concerted effort by all, requiring time to implement incremental steps to get there. While these changes take place, it is prudent to still have the waste-management and sanitary infrastructure necessary to keep the city resilient and its residents healthy.

How long will this project take?

We need a solution for our waste management up and running by the end of 2023 at the latest.  Ideally we want resource consents applied for by April/May 2020 and a decision on our proposal within three to 12 months of lodging the consent applications. This gives us a window of three years to complete the necessary infrastructure for the proposed solution.

How much will this cost?

We have set aside $16 million under the Long Term Plan to consent and construct the proposed waste management infrastructure.

Where is the money coming from?

The funds to construct the necessary infrastructure will be borrowed, with the payments covered by future waste-disposal fees. 

Will there be significant disruption to the area due to this project?

We anticipate very minor disruption. Most of the work would likely occur at the Southern Landfill well away from residential properties. 

Will the local residents be affected in any way – noise, smell, traffic?

We do not expect any major increase in traffic volumes during the construction phase, as any material excavated for the construction of the proposed solution will not be transported out of the area.

We are conscious that the community has concerns about the number of large trucks that visit our facility and will do our very best to minimise any additional traffic movements to the site during the construction phase of the preferred solution.

The intention is not to generate any more traffic. We want to be flexible enough to accommodate any waste-minimisation initiatives that become viable that ultimately could reduce the amount of waste disposed of at our facility, and therefore the number of vehicles. 

How will the natural environment be protected during the development?

Protecting the environment is a priority for us. All work will be done within the constraints of the Resource Management Act and any consent requirements. More specific details on how this will be achieved will be supplied once we know what the proposed solution looks like.

Will it be future proofed?

Any solution proposed will be flexible and robust enough to accommodate future changes to the volumes, types and amounts of waste received, or complement alternative waste-disposal technology.

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