Urban Solid Waste Management

Urban solid waste refers to industrial, commercial, institutional (collectively known as ICI waste), residential, and construction/demolition waste generated in urban areas. Current waste management practices emphasize approaches such as recycling that attempt to divert waste from landfills as much as possible. This is a significant reversal from practices that existed during most of the 20th century, when the main role of the waste management professional was to collect and dispose of waste as efficiently as possible by burning or burying it. Waste diversion has been increasing at a steady pace since the mid 1980s, when governments in most industrialized countries responded to landfill shortages and growing environmental concerns about excessive waste production by introducing municipal recycling programs.

Another significant change in urban waste management since the late 20th century is that it is no longer just a local issue. Because of economies of scale at large waste management facilities, the consolidation of private sector waste management companies, and the lack of local facility capacity, waste disposal and treatment can occur hundreds of miles from the point of generation and even in adjacent countries. Recyclables, particularly waste electrical and electronic equipment (WEEE) and recyclables found in the residues from mechanized material recovery facilities, can be shipped even further for processing. These may end up in lower-income countries, where the labor-intensive separation of different types of recyclables from one another, the removal of contaminants, and the breakdown of recyclable items into their component parts are considerably less expensive but often more environmentally hazardous than in industrialized countries. This entry discusses the waste hierarchy, waste generation, and composition; integrated waste management; the informal sector composed of self-employed individuals who participate in waste collection, separation, and recycling; urban waste management facility siting; and policy tools.

Although recycling is probably the most common waste diversion technique in use today, nearly all urban waste management policies subscribe to the waste management hierarchy, of which recycling is only one element. The ordering of elements in the hierarchy is seen as problematic by some, but most governments have adopted the following ranking, in order of environmental performance from best to worst: (a) waste prevention activities (also referred to as source reduction or waste minimization) that reduce the mass, volume, or toxicity of a product or material at source; (b) reuse; (c) recycling and biological treatment; (d) thermal treatment (typically with energy recovery); and (e) disposal. Despite the enormous effort being put into diversion of wastes by governments, a disappointing aspect of current urban waste management practice is the lack of attention paid to the root cause of waste production, namely, consumption.