by Jan McCarthy
New Zealand has an international reputation as a clean, green environment, but it faces the same issues as other countries in disposing of its waste. Additionally, the country’s relatively small population of 4.2 million – and therefore small internal markets for recovered product – as well as its distance from international markets, creates a unique set of challenges.
The New Zealand Government made an early commitment to reducing the waste stream in 2002, by launching the New Zealand Waste Strategy: a plan which aims to minimize and more effectively manage waste. One of the more ambitious targets is to divert more than 95% of garden waste from landfill by December 2010, so local authorities are now busily reworking their waste management collection and processing systems.
 An illustration of the new urban composting facility designed, built and operated by Living Earth |
As of the time of going to press, Christchurch (New Zealand’s second largest city located on the South Island) will be introducing the largest three-bin kerbside collection for domestic waste in the Southern Hemisphere. Christchurch is home to 382,000 residents and up until now had employed a weekly black bag and green recycling crate collection system. Despite the fact that the crates were overflowing with recyclables, there was problem in that 40% of the black bag items were also recyclable and almost 50% was organic compostable waste.
For years, the city’s residents only had three options for disposing of garden and food waste:
- to compost at home – this is difficult for many residents with small gardens or those that live in apartments/townhouses
- to take their green waste to an ‘eco-depot’ for commercial composting. (This service currently diverts 30,000 tonnes per year from landfill and will continue to operate under the new collection service)
- to place their garden and food waste in a black plastic rubbish bag for landfill disposal.
Faced with the Government’s stringent new guidelines, Christchurch City Council launched its own Waste Management Plan, and this year the Sustainability Policy. Both are designed to make Christchurch the most sustainable city in New Zealand as it moves towards the ideal of ‘zero waste’.
The new kerbside collection plan
As of March 2009 every household in Christchurch will have to dispose of its waste in three wheelie bins:
- a 240-litre wheelie bin for a new fortnightly recycling collection
- a 140-litre wheelie bin for an alternating fortnightly rubbish collection
- an 80-litre wheelie bin for a new weekly organics collection.
More than 400,000 wheelie bins are needed to operate the new service. The bins have been produced in Auckland by a new joint venture company, SULO Talbot, in a partnership between SULO MGB Australia and Christchurch-based Talbot Plastics.
Christchurch currently sends 125,000 tonnes of domestic waste to landfill each year which is equivalent to 327 kg per person. Christchurch City Council Waste Manager, Mark Christison, says the new system should reduce the amount of domestic waste going to landfill by a third, or 42,000 tonnes. The city will also be making a greater contribution to the reuse of valuable materials.
‘This is achievable with the expanded recycling collection and introduction of a kerbside organics collection. We are asking our residents to take responsibility for the waste they generate and help recycle and recover it to protect the environment for future generations,’ he says.
A new Materials Recovery Facility is also being built to process up to 30 tonnes of recyclables an hour, separating cardboard, newspaper and mixed paper, glass, steel, aluminium and mixed plastics.
The Living Earth composting facility
With the introduction of the new organics collection, the city is also building a state-of-the-art composting plant – the largest of its kind in Australasia. Located within the city, the new plant annually processes 65,000 tonnes of the city’s food and garden waste into high-quality compost. Christchurch is well-known internationally as New Zealand’s Garden City and Mark Christison says this is reflected in the disproportionately high amount of green waste generated per household.
The new plant has been designed, built and will be operated by Living Earth – New Zealand’s major supplier of compost to the country’s rural and domestic markets. The company operates throughout New Zealand, it is 50% owned by private investors including the three founders Rob Fenwick, John Tapper and Roger Wark, along with publicly listed company Transpacific Industries. Living Earth currently diverts more than 70,000 tonnes of organic waste per annum from the country’s landfills.
‘Living Earth had the expertise which Christchurch needed to design a plant that would be able to be built and operated within the city,’ says Christison. Furthermore, Living Earth has a proven record of operating successful composting plants within an urban environment and technically advanced systems which will enable the city to compost kitchen waste.
Recent months have seen stringent testing of all equipment to ensure compliance with the required specifications, ready for the launch this month.
A high quality output
Living Earth General Manager George Fietje says the new composting plant represents the latest in proven composting technology, tailored to New Zealand conditions.
‘Compost from the plant will initially provide farmers and horticulturalists, and eventually domestic gardeners, with a high-quality alternative to traditional fertilizer,’ he says. ‘There is strong demand in the agricultural industry for a price-competitive fertilizer substitute. Fertilizer prices have risen steeply due to rising fuel costs and demand from rapidly expanding markets in Asia. A quality product is the driving force. What many growers don’t know is the high nutritional value of the compost that will be produced from this facility.’
Mr Fietje says recent research shows the nutrients in the annual output from the Christchurch plant will be equivalent to 3000 tonnes of fertilizer.
‘Farmers are beginning to realise that chemical fertilizers are not the sustainable answer for future growth. Fertilizers are still needed, but combined with organic material,’ he says.
What happens to the waste?
The domestic waste will be collected at the kerbside by the Council’s contractor, Transpacific Industries, which will deliver the raw material to the new 3000 m2 plant at Bromley. Here it will be sorted, shredded and blended ready for processing in the 18 enclosed tunnels.
The controlled process is divided into two phases. The first process is indoors, within the tunnels, during which time conditions are controlled to maintain optimum temperature, oxygen and moisture. This phase transforms the raw organic materials into a pathogen-free and biologically stable dark-coloured and earthy smelling compost. During the 21 days it takes to complete this phase, all materials are subject to temperatures of 55ºC to destroy any harmful micro-organisms. This ensures the product is safe to use.
 One of Christchurch City Council’s new collection vehicles |
After phase one, the compost is removed from the tunnels and transferred to outdoor windrows to mature. This second maturation phase is about aging the compost to improve quality – similar to storing wine in barrels, it gets better with time! During maturation, nutrients are mineralized into plant available form. Compost is then screened to remove any remaining large particles and quality tested for distribution.
‘In essence, we are bug farmers; it is about ensuring the micro-organisms have a good life to turn the city’s waste into a valuable resource. High-quality compost is produced when you look after the bugs – feeding, aerating and watering them for the best results,’ says George Fietje. ‘You are bringing products with high nutritional value back to the land to restore the fertility of the soils, which in turn will improve farmers’ profit lines.’
Collection without contamination
The real success of the operation, however, rests with the city’s 382,000 residents who will provide the raw material from which Living Earth will produce the high-quality compost. Contamination is the biggest issue facing the city and it could be costly. Mark Christison says the Council has begun implementing an extensive marketing and education campaign, based on highly visual graphics and the brand Love Christchurch; Love Your Rubbish.
 The back wall of the composting plant showing the ventilation ducts and water supply pipelines for the enclosed tunnels |
‘The Love Your Rubbish brand is designed to get residents to think differently about their rubbish. We want them to love their rubbish so they will stop, think, and act responsibly regarding its disposal.’
Mr Fietje says every resident has a vested interest in ensuring the plant produces high-quality compost, as beyond a certain threshold, there is revenue sharing with the city. ‘This new service is not just about diverting waste from landfill but it is about returning the benefits back to the land, and also to the Christchurch ratepayer.’
Fietje believes that Christchurch is leading the way with its new three-bin kerbside collection. ‘A number of other local authorities throughout New Zealand and Australia are watching the introduction of this service with plans to introduce similar models to manage their own waste better,’ he says. ‘Christchurch has to be congratulated for not only future-proofing its city but for also making it easy for its residents to recycle and compost.’
 The branding for the education campaign is designed to make residents take a greater interest in the correct separation of their waste |
Jan McCarthy, Senior Communications Adviser, Christchurch City Council.
e-mail: Jan.McCarthy@ccc.govt.nz
