Figure 6: Major hazardous wastes generated (tonnes) - reported nationally for 2012

Figure 6 shows the largest generated amounts are of biosolids, followed closely by contaminated soils. Although these respective quantities are very similar, biosolids are estimated for all jurisdictions, whereas contaminated soils data is notable by its absence from Western Australian data which, if it was measured, would likely bump it above the national figure for biosolids. Technically Western Australia does report generation of some contaminated soil, but it is so small compared to other jurisdictions as to be negligible. This issue is illustrated by reference to the collection of the largest states’ contaminated soils data in the column graph of Figure 7.

This national comparison of major wastes by quantity is split further by each of the largest states: New South Wales, Queensland, South Australia, Victoria and Western Australia, in Figure 7.

• 
  Some waste types follow generation rates that mirror population-based patterns of consumption (and therefore waste production). These include animal effluent and residues, grease trap waste, biosolids and to some extent asbestos and oils, although the South Australian oils figure is notable due to its extremely low quantity relative to other states.
  
• 
  Alkalis and inorganic chemicals follow a less distinct pattern, which suggests their generation is likely to be from a smaller number of distinct industrial operations present in some jurisdictions but not others, or there are different management or legislative arrangements in place across these states.
  
• 
  Contaminated soils are unusually high for South Australia, compared to other states’ data.
  

When the tonnages of Figure 7 are converted to a per capita basis (Figure 8) this accentuates some of the observations above. The South Australian contaminated soils “outlier” has been removed from the data and recast as Figure 9, to allow closer relative inspection of the remaining per capita data.