In accordance with the ESD Guiding Principles, it has been suggested that waste management strategies must be designed to reduce the net flow of materials and energy associated with the entire waste management system if these efforts are to translate into reduced environmental impacts and prove to be cost effective.
In order to measure if waste management systems reduce the net flow of materials and energy associated with the entire waste management system, Environmental assessment of waste management options should be based on an understanding of the physical system that characterises the waste stream or material management option, as well as all significant changes associated with the management option (from a cradle-to-cradle, cradle-to-grave or life cycle perspective).
Available Assessment Methods
Materials accounting approaches that may be used to define the physical waste system are based on the techniques of mass balance and input-output assessment. Depending on nature of the decision and the system boundary of the study, materials accounting methods employed to undertake this work include:
Life Cycle Inventory Analysis and input/output analysis;
Greenhouse gas assessment (this equates to a scope-limited LCA); and
Energy balance and entropy indicators (this equates to a scope-limited LCA).
Further, if enough is known about the fate of materials through a treatment option, then elemental composition analysis may be sufficient on its own to assess the environmental performance of processing options.
The recommended method for environmental assessment of waste management options is Life Cycle Assessment. In Australia, LCA has been used to assess the environmental performance of national and state based waste management options for more than 10 years. Similarly in Europe, it is generally accepted that LCA concepts and techniques provide solid waste planners and decision makers with an excellent framework to evaluate MSW management strategies (Obersteiner, 2007).
The LCA approach recommended for the environmental assessment requires the decision maker to conduct or oversee the development of life cycle inventory data. This may be requested from the waste industry, LCA software providers or waste management assessment models. Data should be collected in accordance with a data collection protocols and may need to be peer reviewed and independently validated. After inventory data is complete, impact assessment is performed. Categories used to conduct this vary. Multicriteria analysis and economic valuation or CBA is recommended.
The Assessment Method is summarised below and more information is provided in Appendix A.
Physical system defined in an inventory
The recommended approach for identifying physical data flows in an inventory is life cycle inventory analysis. Other materials accounting tools may be used to develop inventory data as long as a system-based approached is used and data sets are gathered for the physical system in terms of material and energy inputs and pollutant outputs.
Inventory data assessed for impact categories of:
Global Warming Potential (CO2-e); Measured in accordance with a life cycle framework and national greenhouse energy and reporting guidelines, NGERS (DEC, 2008)
Water Use (fresh water delivered kL)
Air Toxicity (critical volume Nm3 - measured as the critical volume of air required to dilute pollutant loads to regulatory standards using National Ambient Air Quality, National Environmental Protection Measure (NEPC, 2000) and the Approved Methods for the Modelling and Assessment of Air Pollutants in New South Wales (DEC, 2005).
Water Toxicity (critical volume Nm3- measured as the critical volume of water required to dilute pollutant loads to regulated limits using Australian and New Zealand Guidelines for Fresh and Marine Water Quality (ANZECC/ARMCANZ, 2000)
Solid Waste – amounts to landfill (m3)
Optional data interpretation by normalisation of data or economic valuation
Relative ranking of assessment options or economic valuation.
Environmental Performance Assessment Tables
The following tables (Table 8, Table 9, Table 10, Table 11 and Table 12) provide energy benefits, water and greenhouse gas emissions savings for various material types from recycling.