News | 17 March 2023
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Emissions slashed at Southern Landfill

Emissions at the Southern Landfill reduced by 62 percent between 2021 and 2022 – an encouraging step towards Wellington City Council’s Te Atakura – First to Zero goal.

Pipes at Southern Landfill for the biogas capture system which converts the gas into electricity
The biogas capture system

The total emissions are down from 75,797 tonnes of CO2 equivalent in 2021 to 29,125 tonnes of CO2 equivalent in 2022. 


That’s the same amount of carbon as driving from Wellington to Cape Reinga and back in a petrol car 140,000 times, or charging 5.6 billion smartphones. 


This was mostly achieved through the Council’s new landfill biogas management agreement with LMS Energy, which started in 2022. 


Council invested in an improved biogas capture system which converts the gas into electricity that is injected into the local electricity network – powering the equivalent of 1,100 homes a year. 


Mayor Tory Whanau says the reduction in emissions from the landfill is great news as the city works towards being a net zero carbon city by 2050. 


“It shows what can be achieved when we adopt better solutions to help reduce our emissions. While this is a huge reduction, we still have lots of mahi to do, and need to stay focussed on other initiatives like the implementation of the Paneke Pōneke bike network, greening our city, and investing in environmental groups and organisations.” 


Site at Southern Landfill for the biogas capture system which converts the gas into electricity
Biogas capture system site

The Council’s draft Zero Waste Strategy, for which public feedback is now being considered, provides a framework for many initiatives that will help reduce the amount of waste going to landfill, and further reducing emissions.  


One focus for the draft strategy is diverting food waste from landfill – food waste accounts for 409,000 tonnes of carbon emissions in New Zealand annually.  


Manager of Council’s Climate Change Response team Alison Howard says landfills are responsible for about half of the Council’s emissions. 


“Reducing those emissions is a huge step in the right direction. Through Te Atakura – First to Zero, we have the blueprint that will keep us on track as we work towards our net zero carbon goals.” 


Manager of Waste Operations Stefan Borowy says this year the Council will continue to improve the generator and install a more efficient flare, which will further improve the destruction of methane gas. 


“We are already seeing more gas being extracted from the landfill. Daily gas flows went from 7,600m3 in 2021 to 12,000m3 in 2022, and the Council and contractors are looking at the potential to use heavy machinery at the landfill powered by electricity generated from landfill gas.” 


In other landfill news – Council officers today lodged resource consent with the Greater Wellington Regional Council to extend the Southern Landfill, by constructing a new landfill on top of an old one.


The current landfill’s resource consents are due to expire in 2026, the same time the landfill is expected to be full, so a solution for the city’s waste that can’t be recycled, re-used or composted (residual waste), is needed by then.


The resource consent will be publicly notified by the regional council in due course.


A decision on the application is expected within 12 months. The new landfill is expected to be operational by mid-2026, and the Council’s priority is waste minimisation, which may prolong the landfill’s life or allow it to close early.