Visiting UK academic Professor Stephen Smith notes many similarities between the Australian and British recycled organics industries. The drivers for getting organics out of landfill and onto land are the same, but unfortunately so is the reluctance of regulators to let this happen – despite the science suggesting this reluctance is misplaced. In NSW, however, there has been some recent progress surrounding an exemption for the outputs of AWT facilities.

Organic outputs from alternative waste treatment (AWT) plants are considered waste and cannot legally be applied to land in NSW until an exemption is granted through the government’s 3F “gateway” legislation. Industry frustration with the slow pace of gaining such an exemption boiled over late last year.

But WMAA President Ron Wainberg told Inside Waste that the industry group had a “very positive” meeting with officials from the Department of Environment Climate Change and Water (DECCW) two weeks ago, and while “there were still items of differences, the mood was good”.

He maintains DECCW is being very conservative in its approach, but said there had been “give and take” and industry is confident there will be a workable set of guidelines in the near future. Industry lodged its response to the draft guidelines this week, and expects to see a response from the regulator by the end of this month.

Professor Stephen Smith from Imperial College London, meanwhile, is currently in Australia, and will make a timely presentation on “International Perspectives and Research on Land Application of Recycled Organics” to a WMAA breakfast meeting in Sydney on Tuesday, February 9.

He told Inside Waste the principle driver for looking at new ways of managing the biodegradable fraction of waste – both here and in the UK - is the contribution it makes to climate change through methane emissions.

Some three million tonnes of material (mostly greenwaste) is now being composted in the UK each year, and he said there is “an increasing move to look at mixed residual waste and apply sorting technologies and [mechanical biological treatment]”.

“At the moment, [organic outputs from MBT plants] comes out in various qualities and isn’t really currently deemed as an acceptable output for land application,” with contamination the major concern.

“But I think in Australia there has been significantly more experience in that type of practice and in producing extremely high quality mechanically sorted, stabilised compost residuals.

“There has been considerable progress here to produce high quality products, and to develop quality standards to underpin that.

“The composting sector has been extremely proactive in supporting quantitative research to asses the significance of those contaminants in mixed residual waste compost… [and] the output from that research is entirely consistent with other international research.”

“The [published] research is showing time and time again that the presence of [contaminant] compounds is not a concern… they have no consequence for human health or the environment and should not be a barrier to the use of these materials for soil improvement.”

“There really isn’t a scientific case not to recycle [organics using mechanical biological processes].

“The materials do need to be refined to a high level of quality, but I think the operators I’ve seen here in Australia, and particularly in NSW, are producing material that is of pretty good quality [from a contaminant point of view] and I know they are continually improving that.”

He argues it would be beneficial for the international organics recycling movement if the latest Australian research was published in peer reviewed scientific journals, “and was influencing our [global] understanding of the behavior of these materials, so it might feed into the policy making process”.

“I certainly think the work that has been performed in NSW [through WMAA]… is a unique study in terms of its detail and the breadth of the assessment that was undertaken. That work is certainly of international standing.”


Stephen Smith is Professor of Bioresource Systems in the Department of Civil and Environmental Engineering at Imperial College London. He has 25 years experience investigating the treatment and agronomic properties of sludges and organic residual resources recycled to land and their environmental impacts, including nutrients, potentially toxic elements, organic contaminants and pathogens. Register to attend his WMAA NSW breakfast seminar presentation on February 9 by clicking here.

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