IT MOSTLY happens at night; every night.
Once street lights flicker on, a procession of trucks leave Sydney and head north. Never east, west or south - only ever north.
They wind their way up the M1 and, 12 hours later, cross the border into Queensland, the vehicles unmarked and their contents unseen.
However, what's in the back of these often decrepit trucks has been dramatically revealed following a spate of crashes. Motorists are lucky to be alive as these 30-tonne behemoths spill their filthy loads across the road.
Inside is waste, some of it dug up from its landfill grave in NSW and sent interstate to be buried once again. This bizarre cross-border business is made possible due to a financial incentive that, perversely, was supposed to promote recycling.
It's likely some of the rubbish comes from your home. And it's costing public coffers $114 million a year.
"The waste system is broken when it has become possible to dig up your own waste, truck it to Queensland in dirty, dangerous trucks and still make money," Penny Sharpe, NSW Labor's environment spokeswoman told news.com.au.
"The impact is hundreds of millions of dollars lost to NSW and thousands of dangerous trucks going up and down the Pacific Highway under the cover of darkness."
Recently, a container of waste, on the way to be loaded onto a train, disgorged its load all over a Sydney street. In the past two months, at least six trucks - full to the brim with waste and so lacking in maintenance they have been described to news.com.au as "s**tboxes" - have toppled over. Often just a thin piece of tarpaulin covers their dirty cargo.
One waste management firm, which doesn't transport waste, said the situation was "absurd" and was due to other companies wanting to "make an easy dollar,"
Last year, approaching a million tonnes of NSW waste ended up in the sunshine state. Much of it is reburied around the Brisbane fringe city of Ipswich whose outskirts are pockmarked with landfill sites.
Tony Khoury, the Executive Director of the Waste Contractors and Recyclers Association, which represents the waste industry in NSW, told news.com.au that, "Queensland has become NSW's dumping ground".
The NSW Government levies a charge of $138.20 for every tonne of waste buried in the state.
The waste levy is nothing new, in fact it's been in place, and had worked well, for decades. North of the border, the Campbell Newman-led Queensland Government abolished a similar levy in 2014.
"The idea of the waste levy was to divert from landfill in NSW but now that levy is subsidising the cost of transporting waste to landfill from NSW to Queensland," Mr Khoury said.
"When the levy got past $90 a tonne and Queensland got rid of their levy that was the straw that broke the camel's back."
Even with the cost of trucking the waste north, it has become cheaper to bury NSW's rubbish levy-free in Queensland than keep it within the state.
Perishable rubbish can't be transported but that's about the only bar. Other materials, like plastic and cardboard as well as waste generated from the public infrastructure construction boom in Sydney, is finding its final resting place far from the Harbour Bridge.
"The Environmental Protection Agency (EPA) and the NSW Government has created a secondary market for waste to be trucked from NSW to Queensland," said Ms Sharpe who sits on a NSW parliamentary committee looking into the issue.
Last month, the EPA told the committee they had underestimated how much waste was heading north - it now amounts to 830,000 tonnes annually.
That equals $114 million of lost levy for the NSW Government and, potentially, up to 27,000 truck movements a year or 75 a day.
With counting continuing in the Queensland election, the Government remains in caretaker mode. But in August, Premier Annastacia Palaszczuk said she was "horrified" at the sheer amount of waste crossing the border.
Waste Management Association of Australia (WMAA) chief executive, Gayle Sloan, told news.com.au the Queensland Government needed to reintroduce its waste levy to stop the trade.
"The industry wants this practice to stop. It is unsafe, irresponsible and damages the trust that the community places in industry."
The WMAA has pushed industry members to pledge to not ship waste long distances. Not everyone has signed.
The companies shipping the waste might be quids in but they aren't spending much on their transport operations, said Mr Khoury.
"No one is investing in appropriate equipment to get the waste to Queensland because it could stop at any time (if that state reintroduced its levy).
"It's just low standard equipment, maintenance is not a priority and drivers are pushed to work long hours."
One source who spoke to news.com.au put it more succinctly. "The trucks are s**tboxes, there's no other way to describe them. It's a race, they can't get to Queensland fast enough."
The police are becoming increasingly frustrated at cleaning up the mess from overturned waste trucks.
"Officers from NSW Police Traffic and Highway Patrol Command have attended a number of crashes involving vehicles transporting waste, where various defects were detected, and infringements were issued," a NSW Police spokesman said.
"These types of incidents often cause significant congestion on arterial roads. NSW Police will continue to work with other government agencies to focus on issues surrounding the transport of waste."
Suez Australia, one of the country's largest waste management companies told news.com.au it was "absolutely opposed" to shipping landfill from one state to the other and had signed the WMAA pledge.
"Transporting waste unnecessarily over many hundreds of kilometres is simply an absurd outcome," company spokesman Luke Schepen said.
"The sole motivation for moving all this waste by road and rail is profit. It is hypocritical and quite frankly irresponsible, just to make an easy dollar, rather than doing the right thing."
Mr Schepen said Suez was ready to invest in new waste infrastructure in NSW but was discouraged by the "market uncertainty" created by the levy.
In a statement, a spokesman for NSW Environment Minister Gabrielle Upton said NSW Labor should tell their "Queensland comrades" to introduce a similar levy.
"The long-distance transport of waste is a national problem requiring a co-ordinated national approach," he told news.com.au.
Mr Khoury said he didn't hold out much hope for action as nothing had been done for years.
He wanted the way the charge was levied to be changed to make it less attractive to truck the waste away.
"I shake my head in disappointment at the NSW Government and the EPA. They are devoid of answers. The Government is asleep at the wheel.
"The Government needs to sit down with industry and this whole thing needs to be knocked on the head."
Until then, as the sun sets, another truck crammed with Sydney's rubbish will make its way north.