The din is nearly deafening as Dunedin's new recycling plant roars at its task.
An elevated network of conveyor belts - stretching the 63m-length of a new Green Island warehouse - rattles an assortment of paper, cardboard, plastic, steel and other items off to be sorted.
Mechanical filters and about a dozen busy Cargill Enterprises workers separate one material from another as the never-ending supply of recyclables rushes past.
Down below, trucks reverse into the building and dump the next load of recyclables on to the floor, to be scooped up by front-end loaders and deposited on to the conveyor belts with a crash.
Then, abruptly, the noise stops.
Something has triggered the emergency stop, and the culprit is quickly identified - a dead cat, which someone, somewhere, has decided to try to recycle.
The sight leaves Dunedin City Council solid waste manager Ian Featherston shaking his head, as a worker clambers on to the now-silent machinery to collect the battered remains.
"That just shows you the wide extremes of Dunedinites," he says.
Unfortunately, it is not the worst thing found buried in the city's recycling. That prize goes to two syringes so far spotted by workers and gingerly plucked from the passing stream.
Then there are the old computers and stereos, machinery-clogging plastic bags and even the odd bit of dog faeces.
"We get things we don't want, and you can stress that," Mr Featherston says.
However, dead cats and needles aside, the council remained happy with the results three weeks after the new plant's commissioning, Mr Featherston said during a tour of the facility yesterday.
The facility had been due in time for the launch of the city's new $26 million kerbside recycling system in February.
However, difficulties funding the plant's construction experienced by Hall Bros - one of the companies involved in the council's new system - meant its construction was delayed, and non-glass recyclables were shipped to Christchurch for sorting instead.
The plant was eventually built on Hall Bros land by another Doug Hall company, Antzide Properties, equipped by Carter Holt Harvey and operated by the company's subsidiary, Fullcircle Recycling.
The building also provided administration space for both EnviroWaste and Fullcircle.
Fullcircle Recycling territory manager Taane Royce said the development had cost "several million dollars", although the exact amount remained confidential.
However, the benefits of a purpose-built facility were considerable, particularly when it came to efficient and safe work, he said.
The plant's conveyor belts sorted the non-glass recycling into seven separate streams, increasing their value, before it was compacted into bales - each weighing up to 1.4 tonnes - ready for buyers.
Steel and aluminium was destined for Dunedin buyers, while paper and cardboard headed north to Carter Holt Harvey's North Island mills, which needed 230,000 tonnes of both each year, Mr Royce said.
Anything left over was on-sold to other buyers within New Zealand, or exported, he said.
Glass was handled separately, away from the plant, having been sorted on trucks before shipment to glass bottle manufacturer O-I in Auckland, Mr Featherston said.
About 25 tonnes of non-glass recyclables each day - or up to 500 tonnes a month - were expected to pass through the new plant, and a weighbridge to be installed later this month would help accurately calculate that, Mr Royce said.
Each piece of plastic or paper took just 60 seconds to pass through the screening plant before being compacted and ready for shipment, he said.
Quarterly reports to councillors would in future show how much was being recycled, and where it was going, Mr Featherston said.
