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The informal sector
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plays a significant role in waste handling and
sorting processes in developing nations. The informal recycling
sector may be saving cities as much as 15 to 20 per cent of their
waste management budget. At the same time, if revenues for
some materials decrease, collection is no longer secured. Workers
in the informal sector often work in extremely unhygienic
conditions, with a high risk of accidents and disease (Binion and
Gutberlet, 2012; Jerie, 2016). This can extend social inequalities if
these workers are not included in a formalisation programme.
The typical management of solid waste includes service delivery
– sweeping, collection, transportation and disposal of solid
waste – and treatment and resource recovery, mainly of organic
waste (through composting) and of recyclable waste (through
recovery, sorting and sale). The level of recycling remains basic
because it has not been possible to implement integral systems
to produce recycled products on a large scale. Generally, the
proportion of organic matter exceeds recyclables by a ratio of 2:1.
However, municipalities are working towards a greater emphasis
on recycling waste that can be used in industry. SWM options
are prioritized in an order known as the Waste Management
Hierarchy.
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In general, landfill sites are used for disposal, although
in some mountain cities there are still many open dumping sites.
Challenges and risks
SWM in large mountain cities, as in other cities in developing
countries, is often inadequate or poor. While most countries
have legislation on SWM, it is generally only partially
implemented.
Insufficient and poor SWM manifests itself through low
levels of collection coverage, mixed waste collection without
separation at source, informal recycling of waste on the streets
and disposal of solid waste in open dumping sites (as opposed
to sanitary landfills). In most cities in developing countries,
including large mountainous cities, collection coverage is
relatively low, ranging from 30 to 60 per cent in low-income
countries and from 50 to 80 per cent in middle-income
countries (Scheinberg, Wilson and Rodic-Wiersma, 2010).
The accumulation of solid waste in streets or in open
dumpsites has significant negative impacts on human
health and the environment. When waste in open dumps is
not covered, it can produce unpleasant odours, biogas and
leachate contaminants that can adversely affect air quality,
rivers, underground water sources and soils. Water bodies
A waste dump on the edge of the Bagmati River, Kathmandu.
Photo
©
Flickr/az zut