Green MP Eugenie Sage is backing the idea of building roads out of plastic waste despite the New Zealand Product Stewardship Council voicing concern about the long-term implications.
Sage, the Associate Environment Minister in charge of addressing New Zealand's plastic waste problem, told Magic Talk it "does make sense to consider melting [plastic] down and replacing the oil used in roading".
The minister pointed to a trial by New Zealand infrastructure company Fulton Hogan - in partnership with Christchurch International Airport - to produce road surface by mixing asphalt with recycled plastic waste.
The company collects around 2.5 million litres of used oil each year from businesses such as workshops and garages and reuses them to create PlastiPhalt, described as a "proprietary asphaltic product".
"There are quite a number of trials happening in Canterbury and elsewhere about how well that wears," Sage said. "Because plastics are oil-based, it does make sense to consider melting them down" and use the by-product for roads.
But the New Zealand Product Stewardship Council (NZPSC), an independent organisation, has voiced concern about the long-term environmental implications of using plastic waste in roading.
NZPSC spoke out in mid-2019 after a New Plymouth street was resurfaced with asphalt partly made of plastic, echoing similar trials in India, Australia, Indonesia and the UK.
David Langford, infrastructure manager for New Plymouth District Council, said at the time: "Testing has shown the new material is stronger and should perform better than standard asphalt while also being cost-effective."
But NZPSC member Warren Snow said the initiative was "touted as a revolutionary means of 'recycling' our low-grade plastic packaging, but this isn't recycling, it's just another form of landfilling or dumping a material that is actually toxic".
The group said it cannot be guaranteed that plastic roads will not detrimentally affect the environment as the road surface undergoes wear and tear from use or is damaged by possible natural disasters.
"There's a danger that false solutions like turning our plastic waste into roads makes us feel better about continuing to manufacture and consume toxic plastic products," Marty Hoffart, chair of the Zero Waste Network and member of the NZPSC, said.
Sage voiced a similar concern when she was asked why New Zealand doesn't just burn rubbish in low-carbon incinerators like Sweden does, and using food waste to make climate-friendly biogas fuel.
"Waste to energy where you're burning municipal waste encourages people to put more in their bins and is just disguised as a dump."
The minister said she sees a "future" for what's called anaerobic digestion, a process where bacteria breaks down organic matter, and as the bacteria works, it generate biogas.
The US Environmental Protection Agency explains: "The biogas that is generated is made mostly of methane, the primary component of natural gas. The non-methane components of the biogas are removed so the methane can be used as an energy source."
Sage said the plants in Sweden that burn rubbish in low-carbon incinerators "have a very high capital investment cost, and there is also a toxic residue that is often leftover from the burning process".
In New Zealand, she said, "tech and development has gone into high quality, modern landfills".
"We want to reduce the need for new landfills and capture more materials to reprocess them into new packaging and products so we're not putting stuff in landfill."
The minister's comments follow the release of a report by WasteMINZ that looked into what's ending up in household rubbish and recycling bins around the country.
It found an estimated 181 million containers showed no plastic identification code or recycling information, and 39 percent of household plastic bottles and containers are being sent to landfill, despite being fully recyclable.
"This is one of the first times that we've had a real audit... Often stuff is going to landfill that could actually be recycled," Sage said.
The Government has proposed introducing a product stewardship scheme making companies responsible for where their stuff end up.
It's also looking at increasing the levy rate for landfills by up to $50 in three years.
Single-use plastic bags were banned by the Government in July 2019, and Newshub revealed last month that despite almost 400 alleged breaches of the ban, no one has been prosecuted.