Every alternative investigated
The councils and their joint venture private sector partners considered alternatives to developing a new landfill, including incineration, greater waste reduction through recycling, reusing, composting, and bio-digestion. Though the councils were actively pursuing waste reduction initiatives, and achieving some good results with recycling, it was recognised that there would continue to be some waste that couldn’t be recycled for many years to come and needed to be managed. Waste to Energy (WtE) was proposed and thoroughly investigated.
The research into WtE revealed substantial cost differences compared to developing and operating a landfill. In 1999 when the research was conducted the capital cost for constructing an incineration plant capable of receiving and processing the predicted volumes of waste was $200-250M, compared to the $20-30M for a landfill. Worse still the incineration plant capital development costs have to be paid upfront, compared to the landfill where the cost of development can be spread out over time as the landfill expands to meet demand. The operating cost was also significantly higher for an incineration plant.
Incineration is complex and costly
Building an incineration plant doesn’t remove the need for a landfill because the plant produces large quantities of ash, which can be hazardous, that requires careful handling and burying in a landfill. The incineration plant also produces air borne pollutants that must be monitored and controlled and all carbon associated with the waste, including the carbon within plastics is emitted on the day of incineration. By comparison, modern highly engineered landfills have high environmental security, and almost no risk to water or air quality and the landfills Greenhouse Gas emissions are delayed over many years. To operate efficiently an incineration plant requires a constant supply of waste to burn, which if volumes drop can mean recycling programmes are threatened, as the waste is required to keep the incineration plant operational.
To deliver adequate return on the investment in WtE plants, a specific volume of continual waste (often including potentially recyclable materials) is needed for efficient operation of the plant. Without that ongoing volume, the WtE plant will not be financially or operationally sustainable. This is generally called the “feed the beast” effect, and it does not support New Zealand’s goals for managing and minimising waste, namely “reducing the harmful effects of waste” and “improving the efficiency of resource use”.
Landfills are the best option
Investigations globally, including in Australia, USA, China, and across Europe, indicate the costs associated with WtE are significantly higher than current methods of waste disposal to landfill. If WtE were to be considered, it would need government intervention (that is, government protection for these facilities) as there is in European and other countries, to make it a viable proposition for commercial investment.
The high cost and environmental consequences of WtE meant it was ruled out as an option for Canterbury in the foreseeable future.