2.3 The Waste Hierarchy Guideline Modern methods of managing municipal solid wastes in cities should be the focus of municipal waste authorities in pursuing their sustainability goals. One vital element that should form the basis of sustainable waste management policy is the waste hierarchy guideline, which has now become globally accepted, irrespective of the interpretation given to it in various locations (ISWA, n.d.). The waste hierarchy is the ranking of the options for waste management inline with what is environmentally-friendly (Defra, 2011). The guideline proposes a priority order (in an inverted triangular format) for achieving waste prevention from the source of generation (ISWA, n.d.), and seeks to reduce the loss of resources that can be recovered from materials before being lost into the waste stream (Gharfalkar, et al., 2015).