What happens to your recycling after it goes in the bin?

When you put your recycling out for collection it disappears and your job of being a tidy Kiwi is done.

However what you have just done is given a gold mine to councils to process.

Dr Sharon McIver from Our Daily Waste consultancy in Christchurch told RadioLIVE's Mark Sainsbury that every council in the country has or is in the process of investing in recycling infrastructure.

"There is market value in recycling, and they are getting returns on sorting the recycling and selling it and sending it overseas where it does get recycled," she says.

Councils can make big money if their recycling is done right.

Plastics are taken to recycling plants where they are separated as much as they can be, instead of into one big pile of plastic.

"[The] better separated, the better the return," she adds. 

"Aluminium and cardboard get really high returns so recyclers really want those items."

Plastics are either sorted electronically or by hand into different categories before they find buyers off-shore.

"We could be investing more in being able to find ways to recycle our plastic [in New Zealand]," she says.

Glass is more difficult to deal with than plastic and processes vary between councils.

It can be recycled back into glass when it is colour separated, for example, into brown bottles, clear bottles and green bottles.

In Canterbury the glass is co-mingled and tends to get crushed.

"With a lot of roads being built in Christchurch they can find buyers to use the crushed glass as fillers for new roading," Dr McIver says.

However other councils have issues with glass and what to do with it. Dr McIver suggested New Zealanders need to look at reusing glass instead of recycling it into new glass which costs money.

"It's going to be much cheaper to clean and sterilise glass and reuse it than it is to make it back into glass," she says.

"This is where we need to get smarter.

"It would be great if we could start processing a lot more on-shore and that we didn't have to send it overseas because that in itself is expensive."

However sometimes using glass bottles for other purposes can cause a headache for recyclers.

"I love people for putting their cigarette butts in a bottle and not on the ground but I wish they wouldn't Dr McIver said.

"I know of skips of recycling that have been rejected that have been all bottles because they've had a lime wedge in them."

That comes with a message from her to Kiwis.

"The real message is apparently topless, clean and loose is how we like our recycling in Canterbury."