4.2 Categorisation and Classification

In order to integrate and align waste information, it is essential that a consistent and coherent system for classifying and categorising waste is developed. The current hazardous waste classification system, based on the DWAF Minimum Requirements for the Handling, Treatment, and Disposal of Waste, is in the process of being revised by the Directorate: Waste Stream Management within DEA. The outcomes of this process need to be integrated into the NWMS, since its outcomes are vital to the implementation of the strategy.

 
The document, “Draft Framework for Discussion: Revised Waste Classification and Management System” distinguishes between:
  • Waste Classification: assigning hazardous waste to hazard class and category based on properties, characteristics, and components
  • Waste Characterisation: description of the non-hazardous physical and chemical properties of waste
  • Waste Categorisation: defining groups of waste for the purposes of monitoring and reporting.
An initial draft waste categorisation system, based on the definitions in the Waste Act, has been proposed and was discussed at the research conference. The proposal categorises waste in terms of:
  • General and Hazardous waste
  • Inert and Non-Inert waste
  • The origin of particular waste streams i.e. domestic, health care, commercial, industrial, construction and demolition, power stations, mining, and eWaste.
While the categorisation was broadly supported, there are practical difficulties in distinguishing between waste streams, particularly commercial and domestic general waste. In terms of mining waste; it is not clear whether or not slag is defined as a residue stockpile (which is excluded from the Waste Act). The categorisation of sewage sludge is also a key issue as the management and reporting of this waste stream is currently inadequate. Properly treated, sewage sludge with a purely domestic origin can be considered a general waste. However, when it is mixed with industrial effluent it becomes a hazardous waste. The characterisation of sewage sludge in terms of moisture content is essential to defining appropriate waste management guidelines.
 

The categorisation system needs to be aligned with proposals emerging from the DEA project on the classification of hazardous waste, and a final proposal will be included in the NWMS. All waste information and management systems will be required to use a common categorisation system, which will be described more fully in the NWMS.