1. Prevention
This is the most preferred step in solid waste management hierarchy. It includes using less materials in design and manufacture, manufacturing long lasting products and using less hazardous materials for manufacturing of materials. This step ensures lesser waste generation. This step also focuses on cleaner and environment friendly production. This step is also referred to as Refuse. Refuse to obtain waste creating goods in the first place.
2. Reduction
This step includes checking, cleaning, repairing, refurbishing whole items or spare parts. This is the most important step for minimizing waste generation. Here the waste is not allowed to enter into the disposal system. The wastes are collected in the middle of the production and then fed back along with the source to aid in production processes. This reduces the amount of waste generated. This also includes reducing the amount of waste creating goods you obtain and reusing the waste creating goods that you can. For example: refilling water jugs with clean water from a local water supply location.
3. Recycling and Composting
Recyclable wastes that cannot be reused is recycled by turning waste into new substance or product. This step also includes composting of organic wastes into products that improve fertility of soil.
4. Recovery
This step includes anaerobic digestion, incineration with energy recovery, gasification and pyrolysis which produces energy (fuel, power and heat) and other useful materials. This step ensures conversion of waste into useful energy sources.
5. Disposal
This is the least preferred step in solid waste management hierarchy. This step includes landfilling and incineration without energy recovery.
The main purpose of solid waste management hierarchy is to provide solid waste policymakers, managers, planners and the public, the most environment friendly methods of managing solid waste.
References:
1. Waste Management Hierarchy
2. Waste Management Hierarchy Guidance (PDF)