Wriggling out of waste problem

Waiariki Institute of Technology professor Ian Mclean says home "organic processing centres", such as worm farms, are a great way to deal with organic waste. Photo / File

The phrase "organic processing centre" may conjure images of complex machinery and heavy-tech industry.

But for Waiariki Institute of Technology professor Ian Mclean, it is an accurate description for something very simple - and effective.

"A compost bin is an organic processing centre," he says.

Worm farms, composters and even bathtubs can all be used to turn organic waste to good use - and it's something people should be doing a lot more of, according to Dr McLean.

The professor recently spoke before Rotorua Lakes district councillors about the myriad benefits of organic processing centres.

Making his comments on proposed changes to the city's refuse and recycling systems, Dr McLean quoted his colleague Craig Morley, saying "we need to stop talking about waste, and start talking about a resource".

It's a mindset he believes has always been more prevalent in the rural community, where waste disposal has traditionally been the responsibility of residents, rather than any municipal authority.

And Dr McLean thinks it's something that could translate easily to urban environments, with great benefits for city dwellers.

The first thing, he said, was to get over any worries about worms.

"There are a lot more options than worm farms," he said, noting alternatives such as the Japanese Bokashi-style bins, which only work with food scraps.

But he stressed the slithery creatures were nothing to fear; once installed in a simple worm-farm environment, these natural-born composters are happy to be left to their own devices.

"The wonderful thing about any kind of worm-based system is that they are incredibly robust," Dr McLean said. "They will look after themselves, and just get on with their lives."

The lowly worm has been enjoying some good PR in New Zealand recently.

Beef and Lamb NZ is supporting "The Great Kiwi Earthworm Survey" being conducted by AgResearch, which hopes to determine the national distribution of worms in New Zealand's soil.

AgResearch scientist Dr Nicole Schon has estimated that "up to 6.5 million hectares of pastures in New Zealand may benefit from the introduction of the deep burrowing earthworms alone".

Dr McLean said that in most cases, digging out the worms once or twice a year would be enough to maintain a small home worm farm.

"People also worry about the smells - just keep a piece of carpet over it," he said.

This also had the benefit of trapping moisture in the processing centre, helping decomposition.

Those in rural communities used to dealing with large quantities of organic waste were unlikely to be using home processing centres for material such as hedge clippings, he said.

But even household waste could sometimes pile up.

For him the answer didn't lie in municipal collection for organic waste, as this could be "messy" and unhygienic.

Instead, an old bath tub was a good way to accommodate large amounts of waste.

Just keep it out of the bathroom.