Newsletter and Technical Publications
<Municipal Solid Waste Management>
|Types of special wastes
- medical waste from hospitals, clinics, and laboratories
- hazardous waste in the household waste stream (e.g., oil-based
paints, paint thinners, wood preservatives, pesticides, household
cleaners, used motor oil, antifreeze, batteries)
- used oils
- wet batteries
- construction and demolition debris
- sewage sludge, septage, and slaughterhouse wastes
- industrial waste
Special wastes are those that need special handling, treatment, and disposal
because of their hazardous potential or large volumes. Ideally, these wastes
should not enter the municipal solid waste stream, but quite frequently they do,
particularly in developing countries.
Special wastes can cause significant health and environmental impacts when
managed inadequately. Those who come into direct contact with the wastes, such
as waste pickers, are at great health risk. Toxic components of these wastes can
enter the environment, poisoning water bodies. Hazardous materials can also
degrade MSW equipment.
Special wastes are discussed in this book because of the potential negative
impact they can have on the MSWM system. Still, it is important to point out
that this section only reviews the topic of special wastes superficially; if the
reader is involved in any part of the management process of special wastes,
further reference materials and training are extremely important.
There are a number of special wastes that are generated in an urban area (see
box). These wastes are very different from each other, so they must be handled
Proper management of special wastes is quite difficult in most developing
countries, particularly in those where regular MSW is not managed adequately.
Three issues are always relevant: First, jurisdictions for special waste
management are seldom clear. Second, available resources to manage solid waste
are scant and priorities have to be set. Third, the technology needed to manage
special wastes is seldom available.
In the absence of countervailing reasons, the development of sound practices
in the management of special wastes should follow the integrated waste
management hierarchy applied in other areas of MSWM: waste minimization,
resource recovery, recycling, treatment (including incineration), and final
disposal. The proper application of this hierarchy depends on available
technologies, as well as human and financial resources.
The effective management of special wastes begins with an assessment of their
impacts on human health and the environment. The environmental benefits of
properly handling hazardous wastes can be very large, since in some cases small
quantities of hazardous wastes can cause significant damage. However, even
though all hazardous wastes present some risks, the quantities are not always
high enough to warrant separate collection and disposal. As points of reference,
OECD guidelines and US regulations suggest minimum quantities of material that
need special treatment as hazardous waste. Obviously, specific decisions
regarding the management of special wastes will necessarily depend on the
capabilities of individual countries to carry out such programs.
A number of alternatives for the handling of special wastes have been or are
in the process of being devised in response to the various needs of developing
and industrialized countries. These practices are summarized in this section for
the most frequently encountered special wastes.