Newsletter and Technical Publications
<Municipal Solid Waste Management>
1.7.7 Construction and demolition debris
|Construction debris should be kept separate from MSW.
(credit: Warmer Bulletin)
Construction and demolition debris are generated regularly in urban areas as
a result of new construction, demolition of old structures, and regular
maintenance of buildings. These wastes contain cement, bricks, asphalt, wood,
and other construction materials which are typically inert. In addition, and
mainly in industrialized countries, they may contain some hazardous materials
such as asbestos and PCBs. Very large volumes of demolition waste are generated
in earthquakes and during wars.
City authorities need to avoid disposal of these wastes in the streets, since
these locations can become mini-dumps. On the other hand, MSW landfills cannot
receive these wastes as space can be rapidly overwhelmed. Thus, other
alternatives must be considered.
Sound practices for demolition wastes are based on the concept of prevention,
reuse, and recycling of waste (see box). When these practices cannot be
implemented, proper disposal must be considered. Since these wastes are inert,
they can be used for fill, for example in former quarries, as road base, or, in
coastal cities, to gain land at the ocean front.
Special construction and demolition landfill sites are also an option. Siting
of these landfills is less difficult than for regular MSW landfills since the
potential environmental impact is relatively small.
|Sound practices for reducing construction and demolition wastes
- Waste prevention can be promoted through inventory control and
return allowances for construction material. This ensures that
unused materials will not get disposed of unnecessarily.
- Selective demolition. This involves dismantling, often for
recovery, selected parts of buildings to be demolished before the
wrecking process is initiated.
- On-site separation systems, using multiple smaller containers
in place of a single roll-off or compactor.
- Crushing, milling, and reuse of secondary stone and concrete
materials. There can be a tie-in to approved road construction