The NEPM 15 levels have limitations for data analysis in that they group important waste categories together. For example N Solid/ sludge waste is comprised of such important and different wastes as :
Contaminated soils
Asbestos
Biosolids (recorded as N205 Residues from industrial waste treatment/disposal operations)
Drilling beyond the 15 high-level NEPM categories to the 75 provides much more utility. Analysis of this more detailed code set shows that 94% of all reported NEPM-classified wastes generated in Australia for 2012 can be captured by focusing on the following nine wastes:
