With an increasing number of facilities operating and planned, the composting industry may still be in its infancy but it knows what's needed for sustainability.
IT IS an exciting time for all of us involved in the Organic Recovery Industry," observed Edmund Horan, who is president of the Waste Management Association of Australia and coordinated the International Composting Conference held in Melbourne last September. The following excerpts of papers presented at the Conference give an excellent overview of projects and research underway in Australia and New Zealand:
Composting in Victoria
From Ian Coles and Libby Chaplin, EcoRecycle Victoria: In Victoria, there are no legislated waste reduction targets and landfill prices are quite low. This situation means that recovery of organic materials needs to be based on strong market demand. Over the next three years, this will require action to increase infrastructure for organics reuse; facilitate expansion of organics markets; facilitate attitudinal change to best practice green organics operations within the industry and government; and increase awareness and usage of organics reuse and recovery issues in the community.
There are a number of specific initiatives taken or planned through private sector operators, Regional Waste Management Groups (RWMG) and EcoRecycle Victoria. These include: RWMGs implementing green waste collection, drop-off and processing facilities; an audit of green organics activities in Victoria; conducting industry partnership field trials with the vegetable industry, nurseries, orchards and landscaping contractors; and many other programs.
Through these approaches, it is anticipated that over the next three years, we will see: Reduction in green organics disposed to landfills by at least 30 percent; reduction in food organics-disposed to landfills by 60,000 metric tons, primarily through establishment of a food waste processing facility in Melbourne; an extensive network of drop-off facilities for green organics in Melbourne and regional areas; product specifications for composts and mulches.
Managing woody materials and yard trimmings in New South Wales
From Hannes Partl of Nolan ITU Pty Ltd: Within the Greater Sydney Region, the issue of garden and woody waste is of particular importance since a ban on landfilling garden waste was proposed during 1998 under Action 1 of the State's Green Waste Action Plan. For the Region, annual quantities of garden wastes entering the waste stream are 628,000 t/yr, expected to increase to 657,000 t/yr in 2000, and 688,000 t/yr in 2006. In 1996, 112,000 t/yr of municipal and 20,000 t/yr of nonmunicipal garden wastes are estimated to have been recycled. An additional 24,000 t/yr of woody materials are currently recycled, predominantly from the nonmunicipal sector.
An estimated additional 53,000 t/yr of yard trimmings do not enter the waste stream as it is managed on-site, mainly through home composting - an activity that saves the community between $5 and $6 million annually in waste management costs. Residential yard trimmings collection systems of various frequency and container types have been implemented in 30 of the 54 Local Government Authorities (LGAs) across Greater Sydney. According to Regional Waste Plans, that figure will soon increase to 90 percent of the population who will be provided with a frequent collection (i.e., minimum of one collection every six weeks) or an at-call collection service.
Regarding food waste management in the NSW Regional Plans, on-site (smaller scale) recycling systems have been considered. Reduced food wastage, together with home composting and vermiculture systems, are projected to avoid 48,000 t/yr by 2001 and 77,000 t/yr by 2006. By 2006, commercial and industrial on-site processing systems are projected to manage roughly 37,000 t/yr. Assuming an average commercial on-site system processing 300 t/yr, a total of 125 such systems (comprising composting systems, worm farms or combinations) would need to be established. At present, one large-scale food processing facility with initial capacity of 30,000 t/yr will be established by Waste Service NSW by the end of 1999.
Large-scale organics processing in New Zealand
From Roger Wark of The Living Earth Company Ltd: Established in 1994, The Living Earth Company has been operating a facility in Auckland that composts 35,000 metric tons of yard trimmings annually and will, in the near future, be resited and rebuilt to include biosolids. The Wellington biosolids project -- which will use an enclosed agitated/aerated bed (IPS) system - will be fully operational by January, 2000 producing approximately 40,000 m^sup 3^/yr of compostbased products.
When it comes to the choice of compost technology, selection can be completely different for each community. As our population base is low, large regional facilities appear to be most cost effective. The technology must be market driven to obtain a reasonable return for end products. It is of no value to introduce a plant to create a product that is low quality and subsequently no market value.
Every avenue of sales has to be explored in each community. In some cases, a producer/wholesaler role can be the adopted position, although in smaller communities, a straight retail position direct from the facility can be taken. In Christchurch with "Envy" products, both retail and wholesale arrangements are used. Range of outlets is large - from a single bag to the home gardener, to pallets to the small garden center, to truck and trailer loads to commercial growers.
Opportunities for new products for specific uses need to be identified. Many areas of New Zealand require good quality growing media to replace poor or unavailable topsoil. A large percentage of compost production can be turned into a topsoil substitute product. Additives will vary depending upon base product, availability and cost. Typically they require bark, pomace and sand; basic mixes may require special fertilizer additives for different end uses.
Composting developments in Melbourne
From Michael Strickland of WM Waste Management Services Pty Ltd: Since 1996, each of Melbourne's four RWMGs have awarded contracts for green organics composting that total over 100,000 metric tons annually. There has also been strong growth in curbside collection of organic materials. In the last three years, the proportion of Melbourne municipal districts receiving some sort of curbside green organics collection has increased from 54 percent to 81 percent. The most common service is a twice yearly bundled collection. Increased collection has meant that a large supply of organic materials for composting is now available.
The composting industry in Melbourne is still in its infancy, with much interest being expressed about its longterm sustainability. The industry obviously has come a long way in a short period of time, going from no regional composting facilities in Melbourne three years ago to three plus another close to commencement. Regulations, guidelines and standards are now in place to provide a framework from which compost operators can work. The sustainability for the industry could be further enhanced through: Greater awareness by markets of the benefits of using composted products; Better strategic coordination of state government funding for infrastructure; and Provision of recognized training for compost operators.
For a list of the composting facilities operated by different contractors in different regions of Melbourne, see the report on page 73 of December, 1998 BioCycle.