Managing director of Waste Management, Evan Maehl (left), and chief engineer of Waste Management, Lawrence Smith (right) Photo: Sharon Brettkelly
At an Auckland landfill, modern technology turns waste into energy. But despite being 'world-leading', staffers say we've got miles to go in waste management.
Lawrence James hates to even say 'rubbish dump', even though he works at a place where more than half of Auckland's waste is tipped.
"It is a modern day engineered landfill," the chief engineer of Waste Management tells The Detail.
Standing next to a noisy cannon spraying an odour-killing bleach over the waste mound at Redvale Landfill and Energy Park, Smith explains how the organics from householders' red top rubbish bins and industries are turned into gas that feeds into thousands of homes.
On the surface, this looks like any landfill. But it is what happens underneath that sets it apart from the old fashioned dumps that are still found in many parts of the country and are blamed for high methane emissions from rotting organic waste.
The Detail was invited here after its podcast last month about Ecogas, the company that collects Auckland's food waste and converts it to energy, saving it from landfill.
Waste Management, the country's largest landfiller, was keen to point out that this landfill at Dairy Flat in north Auckland also turns organics into gas and electricity and on a much larger scale.
James points to yellow gas wells sticking out of the ground around the site and explains how an underground network captures 95 percent of the landfill gas at Redvale.
"It's like a vacuum cleaner, so you're vacuuming the gas out of the landfill and it is taken to our energy park where we destroy it through the generators which generate electricity or we flare it off."
But that deals only with the organic waste from households and businesses. Waste Management's managing director Evan Maehl says the ubiquitous soft plastic goes nowhere.
"This is what people put into their red bins because they don't perceive there being an option to recycle it. We do need to get better at what we do with our recycling in this country," he says.
Managing director of Waste Management, Evan Maehl, standing in front of the energy plant at the Redvale Landfill and Energy Park Photo: Sharon Brettkelly
He calls the landfill the backstop.
"We try to recover what we can out of the waste before it gets here and then when it is here we recover the energy from the gas that we collect. Could we do better? Absolutely. But that requires people to care and to make the right choices."
Up to 30 percent of the waste at Redvale is building and construction rubbish that is dealt with separately because of the potential hazard of materials such as asbestos. Very little gas is captured from that waste, but Maehl says his firm is working on recyclable solutions, including a new plant in Penrose to deal with PVC guttering and drainpipe.
"PVC is number three plastic and that's a problem because it doesn't really have a suitable home."
Waste Management is working with the plumbing company Marley to collect the old PVC pipes, shred and pelletise them and turn them into new piles and guttering.
"That's the circularity we want. But that will take one type of plastic, we need to think about what we can do for the rest."
And it has to make money for the recycling business or it won't be sustainable, says Maehl, pointing to the closure of Auckland's Oji paper recyling plant last year.
"We want as many onshore solutions as possible so New Zealand can deal with its own waste and recycling and recovery and not having to export it," he says. "Otherwise we're spending carbon miles sending stuff overseas and we're bringing back the opposite way the finished product."
But keeping the recyclable material in New Zealand is getting more difficult.
"We don't have the manufacturing base that we used to have."
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