Greenwaste Compost Plan Not Viable
'Regional Scale Operation Would Be Required'
October 5, 1999 Tumut & Adelong Times
A report outlining potential horticultural markets for reprocessed greenwaste as compost has found a centrally located composting site for the Riverina is needed to make the process viable.
Tumut Shire Council has recently completed a study investigating potential markets for reprocessing greenwaste in the Riverina as a possible way of diverting the material away from landfills.
A grant of $23,555 was awarded to council last year froth the NSW Government Waste Reduction Grants Program, with funding for the project also provided by Kurrajong Recyclers.
The research project was undertaken by Justin Houghton, a final year student in Environmental Science at Charles Sturt University, Wagga.
Trials were run using compost at orchards in Tumut and Batlow, with the aim to see if compost used in the local area had the same beneficial effects on the soil and tree growth as trials conducted elsewhere.
The project also aimed to establish application methods and costs involved in applying compost to orchards.
Council's manager of development and environment, Paul Mullins, said the results were very encouraging, with good moisture retention and weed suppression recorded throughout, however, initial application costs were high.
"We found that the initial application costs were quite high; around $3.50 per tree applied to intensive orchard systems (1600 trees/ha) and $7 a tree applied to semi-intensive systems (800 trees/ha)," Mr Mullins said.
"These costs are not likely to make compost products a serious option for use on orchards."
The main cost to the process was chipping, almost half the purchase price of the compost, and transport to a composting site.
"If these expenses could be offset by a redirection of landfill handling costs, the overall process would become more viable," Mr Mullins said.
"Taking into account landfill handling, if the greenwaste was to be buried, the reviewed costs were about $130/tree for intensive orchards and $2.60/tree for semi-intensive.
The final stage of the research involved a survey of orchardists.
Seventy-four percent of growers said they would use composted products on their orchards; 40 percent indicated they would be prepared to pay for the product, with a further 52 percent saying they needed more information. Only 10 percent gave a definite no.
"From the results of this project it was found that in order to supply the amount of compost needed, it would be necessary to have a centrally located composting site for the Riverina," Mr Mullins said.
"This would need to be easily accessed by the largest number of councils in order to receive the most greenwaste composting."
The report will be forwarded to the Riverina Eastern Organization of Councils (REROC) waste committee.
"Our scale is not viable," Mr Mullins said, "but who knows, in the future we could end up with a regional composting centre."