Huge plastic bladders, each weighing as much as 20,000 plastic bags, are being dumped in landfills with no controls and no record-keeping.
Government and other agencies are largely blind to the growing problem of flexitanks used to import and export everything from wine, to paint and pharmaceuticals.
One North Island trucking company alone has dumped 450 of the bladders in tips in the last year - the equal in weight to nine million plastic bags. The company asked not to be identified.
Each bladder had been used just once.
A supplier of tanks to exporters, that also requested anonymity, said demand was growing.
They protested that the tanks were fully recyclable, but did not know what their customers did with them after they are used.
"So if they are ending up in landfill, well, there's absolutely no reason why they are going into landfill.
"I can't really tell you what my customers do. I hope most people use their common sense and do the right thing."
However, the county has no infrastructure to recycle the tanks.
One recycler, Canterbury's Plasback, has tried, and found washing out the flexitanks was often "a challenge" and "difficult".
No data, no action
The problem undermines consumer-led attempts to phase-out single-use and non-recyclable plastics, such as plastic bags and straws, and authorities have no visibility and no data on the problem.
"Flexitanks do not feature in current proposals to phase out single-use plastic items," the Ministry for the Environment said in a statement to RNZ.
"There are currently no work programmes looking at flexitanks, or documentation on our website about this product. The Ministry... does not currently track the use of flexitanks ... we do not have a record or figures on their import, use or disposal."
The tanks are up to the size of a shipping container when filled, and are transported inside shipping containers so as not to rip them. They range in size from 12,000-26,0000 litres.
Importers use thousands each year for just a single trip, and exporters use hundreds more, at least. The New Zealand use is a fraction of a global market for the cheap and lightweight flexitanks, which are mostly China-produced, and are taking over from hard-plastic and steel containers.
A distributor offered a rough estimate of who's using what:
- big food companies each import between 300 and 500 flexitanks per year
- wine companies import 20 to 30 tanks of wine at a time to blend
- waste oil is exported in the bladders, and transformer oil for power stations is imported in them
- paper manufacturers often import FennoSize compound this way
- pharmaceuticals are increasingly transported in them
A main driver in demand for the bladders has been growth in the global trade of beverages, said analysts.
No data was forthcoming from New Zealand's peak waste minimisation body; "Sorry, flexitanks aren't a subject area we have any expertise on," Wasteminz said by email.
Lobby group Zero Waste also had little to go on when RNZ asked about the tanks.
"It needs to be on the radar, only because of the scale and the weight and the volume of this material," the group's chair Marty Hoffart said.
"We don't see it, it's not the face of waste, like plastic bags and coffee cups."
The tanks are not on the radar at industry body Plastics New Zealand.
"There's really not a lot of data on that," said chief executive Rachel Barker.
"It is one of those things that we probably haven't reached yet.
"There's some areas that need more urgent attention, such as kerbside packaging, recycling, and making sure that we can actually deal with some of that waste onshore.
"We can only basically eat one bite of the elephant at a time."
The scarcity of data is matched by a scarcity of muscle to take the issue on: the country's lack of recycling infrastructure has been painfully shown up since China stopped taking foreign waste in 2018.
The consumer push to ban single-use supermarket bags has not touched the sides at the industrial end, where the market for the Gulliver-sized bags is a billion-dollar global market which is expected to triple in size by 2027.
Demand for the bladders is dominated 93 percent by single-use bags.
Weighing up the alternatives
But despite the challenge flexitanks pose, whether to use them or not, isn't straightforward.
"If you think about the alternative, you're going to have either a fairly hefty tank of metal or plastic that is going to use much more fuel to actually ship," Barker said.
Reusable flexitanks are a growing niche market, and "would definitely be the optimum", she said.
Some tanks have a single layer of polyethylene, often made from recycled plastics. Increasingly however, the tanks have triple layers, which include polypropylene.
Multiple layers provide more oxygen and humidity barriers, important for transporting beverages and protecting against rips inside a container.
If a tank had a mix of plastics, that could make recycling difficult, said Plasback manager Chris Hartshorne.
And that was not the only problem.
"We have collected some of these in the past," he said.
"Largely [reuse or recyclability] depends on what product's been inside these tanks.
"If they're food grade, you're dealing with kinds of things like syrups and sticky materials - you do get problems if they're not washed out properly, they're very difficult."
There was no existing set-up that could handle them, he said.
"You've got to come back around to this idea of the product stewardship schemes to make sure that people who are creating all this waste take some responsibility for it," Hartshorne said.
Plasback's experience recycling dirty plastic waste from Canterbury farms showed it could be done.
Some farm plastics suppliers supported the scheme financially, so the cost to end-user farmers had been kept steady for 15 years.
"The Government is working towards that, with a regulated product stewardship scheme for other plastic packaging," Hartshorne said.
Consultation wrapped up earlier this month for the proposed national product stewardship scheme, which considers reducing harm from waste in six priority products, including plastics.
However, the Environment Ministry had just a single staffer working on product stewardship as recently as mid-2019, council records showed. It now has about four.
The government's focus, reiterated in Labour Party election campaign policy, is on phasing out small non-recyclable plastic items like cutlery, produce stickers and cotton buds
"We do a lot of work around plastic packaging, but it tends to be retail-centred," said Rachel Brown who heads the Sustainable Business Network.
There was "absolutely" a blind spot at the industrial end that must be dealt with, she said.
"You start where the energy is, and the energy has started the face-to-face consumer stuff, because wholesale is quite a hidden story."
The first step was to find out how many flexitanks were being used by who, and for what, Brown said.
Greenpeace perceived some cynicism at work.
"Flexitanks represent a failure of care and imagination by packaging and transport companies," the environmental protest group said.
"The pattern we are seeing in this space is that industry says 'don't worry we've got this' ... and then we find it turning up in landfill."
Local Government New Zealand had not been approached by any councils around issues with flexitanks, LGNZ told RNZ.
However, any national product stewardship scheme might have to be widened as "preferences and products" changed, it said.
"Many producers of packaging and other goods claim their goods are recyclable, when in fact ... most are only recyclable with millions in ratepayer and taxpayer-funded infrastructure," LGNZ said.
This demanded that cutting down on plastic use be the first step, it said.
Marty Hoffart of Zero Waste weighed in on the need to widen and toughen up the proposed stewardship scheme.
"We've been making plastics since the 1950s; it's one of the least recycled products out there, we need to step it up."
"Let's not pretend it's not going to landfill."
Demand for flexitanks fed the front end of demand, he said; "If we don't stop digging oil out of the ground to make all this plastic we'll never stop climate change".
He is pushing for:
- compulsory recycled quotas in products to provide an incentive to recycle
- building the cost of recycling into the purchase price
- regulated, mandatory product stewardship
With consumer pressure setting the priorities, Plastics NZ's Rachel Barker found it understandable flexitanks were not on the agenda - but imagines they would be.
"We are starting to see a lot more product stewardship across the consumer space, the same sorts of things we will also eventually see in the industrial" field, she said.
Wasteminz, while silent on flexitanks, chimed in: "Any company that is bringing a new product onto the market should be thinking about its end-of-life disposal options."
Manufacturers should consult with the recycling sector during the design phase "to make sure their product can be recycled", it said.
Hoffart said public polls showed one thing: "We're all sick of plastic."