The value of composting

March 25, 2008

"Australia’s soils typically contain between half to one percent of organic matter. It should be 5%," according to Craig Hartin of Bio Tech Recycling, which is the biggest composting company in agriculture in NSW.

Operating from Hillston in the south, to Moree in the north of NSW, the company has been working primarily with cotton trash, turning it into valuable compost. The company which started two years ago, is now working at five sites in the Gwydir Valley and looking to establish operations in Dalby and Emerald next year.

Mr Ross Munro and Mr Craig Hartin, who is a nutritional consultant, addressed the Community Services and Planning committee meeting held in Warialda, last Thursday. They contacted the Gwydir Shire Council after being advised of Council’s interest in composting waste by a reader of The Bingara Advocate who read the article in the Feb 19 edition.

Mr Hartin and Mr Munro made a presentation to the committee about their company, explaining how it could contribute to Council’s future plans to take over recycling of the Shire’s waste. Mr Hartin told the meeting that the future for his company is in municipal waste where "the big boys" wouldn’t find it viable, the size of their machinery being way too large for operations that Bio Tech Recycling undertakes.

Mr Hartin said he didn’t expect to make any money out of this initially, but "what we are hoping to do is to establish a cluster of Councils to work with us." Bio Tech Recycling has sold 20,000 tonnes of compost produced from cotton trash and manure in the last 18 months.

The major demand for the product comes from two large farming operations in the north west. The biggest problem for the company is accessing a continual supply of compostable matter. Mr Hartin said he would be looking at utilising waste from feedlots and chicken sheds in the near future.

Composting is a biological process. The mechanical aspect maintains the environment and ensures that the ratios of additives are correct. The value of the product for fertilising soil ranges from none to extremely valuable, depending on its composition.

Municipal waste is at the lower end of the value scale but it can be supplemented with fertiliser or minerals, or mixed with a higher grade of compost, for agricultural use.

Mr Ross Munro said that he wanted to look firstly at the waste which is easily usable. He advocated starting small with the obvious things like paper and cardboard, in fact any cellulose product. Trees are also in this class, but they need to be chipped.

It may be necessary to store this resource until there is an amount which would be economically feasible to chip using a contractor, Mr Munro suggested. "This is the direction the farmers and the community wish to go. We have no difficulty in disposing of compost… particularly with the cost of synthetic fertilisers going through the roof." Mr Munro stated.

The company is interested in profit sharing and in giving something back to the suppliers, particularly in agricultural areas. Councillor Wearne suggested that "if we can receive a benefit from waste, we can reward ratepayers who co-operate with the recycling."

Mr Hartin said that the quality of the raw materials will influence the nutritional value of the compost. The ratio of nitrogen, typically found in manure and the ratio of carbon, supplied by the tree chipping, affect the fungi and bacteria in the compost. The company is seeking a diversity of waste, as this leads to a diversity of microbes which eventually make better, healthier soil.

Gwydir Shire Council would need to provide an area of land where windrowing of the organic matter could take place. This may be up to about 4 hectares of land. The site must be on a slight slope for drainage, however, no run-off can enter the water supply. A lot of water will be required, however, the water from the sewage plant would be acceptable. Food scraps are not being considered at this stage, as they require treatment using a "digester", otherwise it attracts vermin and could be a source of unpleasant odours. Digesters, however, do not exist on a small scale, at present.

The company would be composting paper and cardboard in the first instance, which leads to a very good product, according to Mr Hartin. "You can value add with urea or sulphate of ammonia," he said. In response to a question from Cr Pankhurst, Mr Hartin said that the waste takes about 12 weeks to compost into a usable product. This time frame is influenced by the weather and daily temperatures. Mr Hartin said that the co-principals of Bio Tech Recycling had a history in recycling and that the company would be looking to do much more with Council than simply composting but that it was a starting point.

Mayor, Peter Caskey said that the Council could save transport costs by not having to take recyclables to Inverell. He also believed that there would be a market for the end product within a 30 km radius of the composting site. Cr Wearne concluded from the presentation that "ideally, we would be able to generate enough income from this to significantly reduce our waste management bill."

Council officers were asked to present a recommendation from the proposal to the next Council meeting. Cr Caskey advised the meeting that the council needs to make a decision on which direction it is going to take with regard to waste management and then put the necessary plans in place.

Compliments of The Bingara Advocate