Despite a successful start at the beginning of implementation, South Australia's first five-year zero waste strategy (2011–2015) has been experiencing the consequences of the global economic downturn. There has been a significant government investment of about AUD4.5 million for waste infrastructure, which boosted an additional AUD10 million in industrial ventures and stimulated an increase in tonnes of material diverted from landfill and, in some cases, resulted in additional employment in South Australia (ZWSA, 2013b). The core zero waste goals are a 35% reduction (with a milestone of 25% by 2014) in landfill disposal from the 2002–2003 level by 2020, and a 5% reduction in per capita waste generation by 2015. The waste strategy has two milestones for municipal solid waste diversion: a 60% reduction by 2012 and a 70% reduction by 2015 (ZWSA, 2011a). In addition, for C&D waste, targets for diversion from landfill were set to 85% by 2012 and 90% by 2015.
Using time series waste generation and management data and by considering the projected targets in the waste strategy, waste data for the years 2015 and 2020 were projected, adapted and are presented in Table 3. The following four assumptions have been made to project waste generation and management in the Adelaide metropolitan area:
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the waste generation rate increased 42% in 2010 compared to the previous year because municipal waste streams include C&D waste and a massive infrastructure development project has started in Adelaide, hence the overall generation of waste has increased significantly;
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the waste generation rate is assumed to have increased by 25% (the same as in the past 5 years) during 2015 and 2020;
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waste composting is assumed to have increased 12% (the same as in the past 5 years) during 2015 and 2020;
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waste sent to landfill is assumed to be meeting the targeted 35% reduction in landfill disposal from the 2002-03 level by achieving the 2020 milestone of 25% by 2014 as per Zero Waste SA's strategy.