Organic Waste Collection

Issues to consider

A local authority, community or individual looking into organic waste collection and processing will have to consider:

• The waste stream
  What types of organic waste are being produced and in what quantities?
• Collection
  Best available collection systems, dependent on size and location of waste stream
• Processing
  Best available processing systems, dependent on type of waste stream and market or uses for end product
• Market
  Uses or market for end product, dependent on size and type of waste stream.

A number of factors will influence decisions in these areas, and these will vary widely from location to location.

Recommended steps

When investigating options you should:

• Establish best practice - research what’s available.
• Analyse present waste flows - where does waste come from, in what quantities, who is generating it, what problems might arise, what opportunities are there?
• Take account of current practices - what systems do you already have in place, what operators are already providing services?
• Solutions will then begin to become clear - use existing companies, personnel and systems and incorporate a newly designed system into existing waste management practices.

Composting facilities in New Zealand

There is a growing number of composting facilities now handling food and green waste in New Zealand.

These range from in-vessel systems to simple worm bins and include:

• Waitakere City Council - residents bring their separated green waste to the transfer station in Waitakere. The Vertical Composting Unit (VCU) system is the central tool in the green waste recycling programme and collected 800 tonnes of green waste in it’s first year.

• Mackenzie District Council was the first Zero Waste Council in New Zealand to implement a three bag collection system to include the weekly collection of food and green wastes (from households and businesses) in green bags. Council has invested in a 25m³ VCU called J.O.A.N (Just Organic And Natural) that is installed at one of the three resource recovery centres.

• Innovative Waste Kaikoura diverts 2800m³ of greenwaste from landfill each year. They have built a Horizontal Composting Unit (HCU) that is fed green waste and putrescibles from restaurants in Kaikoura.

• Rodney District Council uses a Hot-Rot system to process screenings of sewage sludge (mixed with green waste to reduce moisture content).

• Wastebusters Trust Canterbury’s Education Centre is home to a range of worm farms and composting systems. These enable the public to see these systems in action as well as come and ask the experts about problems with home composting units. Over 50 schools in the Selwyn and Ashburton district have worm farms.

Technologies & contacts

There are a number of methods for processing organic waste. These include:

• Composting
• Active Pile Systems
• Windrow Composting
• Drum or "Dano-type" systems
• In Vessel Systems
• Modular In-Vessel systems
• Tower Systems
• Anaerobic Digestion
• Swine/Animal Food
• Vermicomposting
• Bokashi and effective micro-organisms

Experts in the field:

• The New Zealand Earth Worm Association
• VCU Technologies
• Waste Not Consulting
• Global Vermiculture Limited
• Earthmaker
• W.O.R.M.S
• The University of Canterbury has produced a website, UC Composting, for composting research and practice in New Zealand and the South Pacific. Go to www.civil.canterbury.ac.nz/compost  for more details.
• For more information about Bokashi and Effective Micro-organisms (EM), go to www.kiwiorganics.co.nz/bokashi .

Reports

Kerbside Collection of Domestic Kitchen Organics by Christchurch City Council - August 2002

This report investigates the feasibility of collecting domestic kitchen organics (food scraps) at the kerbside in Christchurch. An eight week trial was conducted. The report analyses the costs, operational issues and community acceptance and participation in the scheme.

To see the report, go to www.ccc.govt.nz/Compost/KitchenOrganicsCollectionTrial.asp

Composting Report - Zero Waste New Zealand Trust, June 2002.

This report highlights some of the approaches taken by councils and community groups throughout New Zealand in dealing with the organic fraction of our waste stream, as well as case studies from around the world.
It demonstrates there are many strategies available for diverting organic waste to beneficial uses.

Composting techniques in NZ (PDF 133 KB)