ACT Minister for City Services Chris Steel has released an information paper about producing power and fuel from household waste. It’s a topic that warrants a serious conversation. But if we want to sort the trash from the treasure in the paper, and make sure we’re not just recycling bad ideas, we need a rigorous cost-benefit analysis of the options presented. Without that, the information paper is only fit for the waste bin.
The discussion paper is based on a “waste hierarchy” that gives priority to re-using materials over recycling, and recycling over disposal. If waste must be disposed, incineration and gasification are preferred over landfill, which is considered to be the worst option. The government’s stated aim is to increase the level of resource recovery from the ACT’s waste stream from about 70 per cent today to 90 per cent by 2025.
Waste management is a highly complex issue, with no easy answers. Different approaches have pluses and minuses that differ between regions and over time as the population grows.
High temperature incineration of household waste, for example, requires expensive infrastructure and air pollution control, but reduces the need for landfill sites. However, carcinogenic dioxins and furans as well as fine particulates are produced during incineration. Pollution control equipment can capture a proportion of these by-products, but the toxic fly ash produced still needs to go to specialised landfill sites, where leaching of toxins can occur.
Heat and oxygen can also be applied to various materials to convert them into gases that are then used as fuel (gasification). Heat can also be applied in the absence of oxygen (pyrolysis) to produce liquid and gaseous fuel, as well as charcoal (biochar). Neither of these two techniques has yet been developed on a large scale.
The Refuse Derived Fuel (RDF) technique is already used commercially. In this, combustible waste like wood, non-recyclable plastic, car tyres, carpet and paper are shredded and used to supplement fuel used in kilns during the production of concrete. Residual ash is used in the manufacture of the concrete, and any noxious emissions from burning the fuel become someone else’s problem if RDF is exported to a facility outside the ACT. But without sufficient market demand for the fuel, the widespread production of RDF in Australia could threaten the viability of an ACT facility.
Anaerobic digestion involves composting biodegradable waste. In the absence of oxygen, microorganisms can produce biogases and organic material that can be used for fuel or fertiliser in pellet form. While attractive as a purely ‘organic’ solution, this method depends on the removal of toxic materials and plastics, before treatment. Because of this, a high level of long-term commitment by households is essential. Not only is the infrastructure expensive, but the availability of a market for fuel and fertiliser will determine the viability of the scheme.
The fundamental flaw in the government’s information paper is that it fails to provide a comprehensive analysis of all feasible waste management alternatives in a way that allows valid comparisons. It is therefore impossible for ACT residents to make informed choices between them.
For example, the use of incineration plants in populous cities in Europe and America is advanced in support of using the technique in Canberra. The paper also claims that “emission limits are strict and regularly monitored”, and that no significant health effects “have been reported”.
In truth, peer-reviewed, long-term research into the health effects of incinerators is limited. However, a comprehensive study by the British Society for Ecological Medicine reports birth defects, cardiovascular disease and lung cancer due to emissions of particulate matter in toxic fly ash and gaseous emissions. Modern incinerators produce less air pollution but at the cost of generating more toxic fly ash, which is also released into the atmosphere during maintenance and start-up procedures. The study also points out that the bottom ash and fly ash produced during incineration is only about half the volume of compacted waste, so that any saving on landfill sites is not as significant as is commonly assumed.
Government monitoring of incinerators has typically lacked rigour, been infrequent, measured only a small number of compounds, and lacked biological monitoring as a backup. Like asbestos and cigarette smoke, it may take time to definitively identify any health effects of incineration plants. Is it justifiable to risk the health of future generations in the absence of sufficient knowledge?
Moreover, Minister Steel’s information paper cherry-picks its techniques. Towns in Sweden and the UK, for example, harvest the heat from local crematoriums to heat swimming pools and buildings. Given that a new crematorium is currently being proposed for the outskirts of Narrabundah, the paper is surprisingly silent on the energy-saving possibilities for the ACT.
Despite being on the nose with many residents, the option of landfill is not considered at all, save for noting that some methane can be captured. But land is relatively more plentiful and cheaper in Australia than Europe.
Without justification, preference is given to expensive infrastructure solutions such as incineration and anaerobic digestion, both of which, incidentally, also require land in or near major cities.
Maximising the extraction of recyclable material before dumping rubbish makes sense if the social benefits exceed the social costs. If a credible and sustainable waste management policy is to be implemented in the ACT, it needs to be evidence-based. A comprehensive and rigorous social cost-benefit analysis of all the feasible alternatives would be a good first step. Without it, any recommendations should be trashed.
Leo Dobes is an honorary associate professor at the ANU Crawford School of Public Policy, where he teaches cost-benefit analysis. He is also president of the Griffith Narrabundah Community Association.