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Caring for our Environment and Community

As part of the lead-up to our Pūrongo Toitū, 2023 Sustainability Report, we're highlighting our five sustainability initiatives that fall under our WM Porohita (To be circular) sustainability strategy.

Our Interations with Te Taiao (The Environment)

WM New Zealand only invests in technology and solutions that protect the environment. Our state-of-the-art landfills and energy parks are among the best globally, exemplifying our dedication to sustainability. We prioritise the recovery of materials, ensuring that what remains is safely and efficiently disposed of in modern, engineered landfills designed to protect te taiao.

Our landfill innovations

Although recovery of materials is always our priority, what remains must be safely disposed of, and for New Zealand the best solution is a modern, engineered landfill. These are nothing like dumps of the past and are designed and operated by engineers to protect the environment while extracting remaining value from the waste.

WM New Zealand’s landfills capture more than 90% of biogas naturally created from organic waste as it decomposes, stopping harmful greenhouse gases from entering the atmosphere, and either destroy it, use it as fuel for landfill operations or convert it to electricity to feed back into the national grid. Redvale Landfill & Energy Park remains Auckland’s largest renewable energy creator.

Class 1 landfills (which take household waste) have reduced their biogenic methane emissions by 17.9% since 2017 – well ahead of the NZ target of a 10% reduction in biogenic emissions from 2017 to 2030. In terms of NZ’s commitments under the Paris Agreement, Class 1 landfills reduced their CO2e emissions by 53.1% since 2005 – achieving the NZ target 9 years ahead of schedule. The rest of the country’s gross emissions (excluding class 1 landfills) have only reduced 8.3%. Class 1 landfills emissions as a percentage of NZ’s total gross emissions have reduced from 3.0% in 1990 to 1.4% in 2022.


Kendra the BeneVap: Revolutionising Leachate Treatment

The wondrous power of the BeneVap has been introduced to Kate Valley Landfill & Energy Park. This incredible machine, named Kendra, was installed at Kate Valley in 2023 and now treats most of the leachate produced at the landfill.

It uses landfill gas to evaporate water from leachate, with the concentrated leachate then returned to landfill. The plume you see in the image is steam as the water content within the leachate is evaporated.

Like Redvale’s BeneVap Irma, Kendra has many benefits, including:

  • Evaporating up to 50m3/day of landfill leachate at approximately 300m3/hr landfill gas consumption rate, making her one of the most efficient leachate evaporators in the world
  • Because she uses landfill gas which may otherwise be flared
  • Reducing transport emissions when leachate levels have required transport to the Bromley wastewater treatment plant in the past.

The technology is so environmentally friendly and efficient, that there are plans to install another BeneVap at Kate Valley over time. BeneVaps will also be introduced to our other landfill sites.

Project Manager Mike Beretta says each BeneVap that is ordered from Australia comes with a name, which is why we have Irma at Redvale and Kendra at Kate Valley.

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Remediation of old tips

There are at least 300 old dumps scattered around Aotearoa, many of which are at risk of spilling into waterways and the ocean.

It means decades-old rubbish, which has simply been thrown into a hole in the ground, could increasingly cause massive pollution events – and the risk is getting worse as extreme weather events ramp up due to climate change. 

WM New Zealand is increasingly becoming involved in old dump cleanups and remediation. We are currently partnering with Waitaki District Council to stop three coastal tips falling into the sea. Two of the dumps are located on Beach Road, three kilometres south of Oamaru, where people have been flytipping (illegally dumping) for years. The third is the now-closed Hampden landfill that was operated by the council from 1970 to 1996 and is located next to the beach.

The waste is removed to a newly built engineered cell at Palmerston Landfill. Part of the work involves capturing and relocating the tussock skinks that make their home at Hampden tip. Once the skinks have been safely moved rubbish from the Hampden tip – which is currently falling into the sea – will be taken to the new cell at Palmerston Landfill. There is around 30,000m3 of waste that needs to be relocated before it washes out into the ocean.

Amazingly this was once an official council disposal site - something that would never be built or allowed today. The project, named Project Reclaim, is widely supported by the public, and regular updates are published online.


Regeneration and Biodiversity

We are committed to planting and improving biodiversity outcomes around our landfills. Our annual planting programme at Kate Valley saw over 1,000 kahikatea trees planted in nearby Tiromoana Bush in 2023, to add to the regenerating native forest of black beech, five finger, kahikatea, kanuka, kōhūhū, lacebark, manuka, ngaio, ribbonwood and tōtara.

Bird numbers have been bolstered by an ongoing pest eradication programme, as well as the overall bush regeneration and tree planting. Rare native birds including the shining cuckoo (pīpīwharauroa), kererū and tomtit (ngirungiru) spotted in the bush.

Other native birds like silvereye (tauhou) and fantail (piwakawaka) continue to be common in the reserve. The nationally “at risk-declining” spotless crake (pūweto) and marsh crake (koitareke) have also been sighted in the wetlands. Both species are very secretive and rarely come out into the open.

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Supporting our Community through Climate Challenges

In 2023, Auckland was hit hard by the Auckland Anniversary Weekend flood events, and then just weeks later the country, particularly the East Coast, was battered by Cyclone Gabrielle.

It was a hugely difficult time, and our teams stepped up. Our Auckland Inorganics crew worked with the Defence Force to clean up the streets of Tāmaki Makaurau, removing debris and flood-damaged furniture, and other household items. What was supposed to be a 1-in-200-year weather event, but just a few weeks later Cyclone Gabrielle arrived, devastating Gisborne and Hawke’s Bay.

At WM New Zealand we had patchy contact with the Hawke’s Bay and lost contact altogether with our Gisborne team for almost four days. It was with great relief we were finally able to confirm everyone was unharmed – although many had damaged homes and property.

What followed next, was the clean-up efforts from both our teams in the Hawke’s Bay and Gisborne, the support they gave to their communities and the care and aroha for each other was inspirational. Our teams prioritised servicing aged care homes, prompting Ryman NZ CEO Cheyne Chalmers to write a letter of thanks for “incredible help and support”. She said: “Please know that your actions have helped hundreds of our most vulnerable residents.”

When they were able to, residents came to the transfer station at Gisborne in droves with trailers of flood-damaged goods – many of which were uninsured and irreplaceable. Our team treated everyone with kindness, even coaxing some smiles in very difficult times. Later they gave out chocolate packs and wrote messages of support to everyone who came across the weighbridge. One woman was in tears as her whole house load was on two trailers and she had no insurance – but she was touched and left with a smile.

Both the Gisborne and Hawke’s Bay teams turned up to work immediately following the cyclone and mucked in to try and get services up and running again as fast as possible. This was despite having just lived through a very traumatic time that affected everyone they knew. That’s just the way we do things here, a team member explained.


WM Porohita Updates

These stories paint a wider picture of our WM Porohita (To be circular) sustainability strategy, which is also our company strategy.