Civil Engineering Reference
In-Depth Information
Case study 1: selection of a municipal waste
treatment system
This example deals with a major ecological issue of concern for sustain-
able development: the problem of municipal waste. This generally con-
sists of organic substances, paper, metals, textiles, glass, synthetic
materials and small quantities of a large variety of toxic substances.
Municipal waste is generally collected in most European cities,
although in deteriorating neighbourhoods, removal systems do not
always work adequately because of a lack of public funding.
In Europe, between 150 and 600 kg of municipal waste is produced
per person each year. On average, each European produces more than
500 kg of waste per annum or 1.5 kg of waste each day. Estimates pro-
vided by the OECD for western Europe indicate an increase in the pro-
duction of municipal waste at the rate of 3% per annum between 1985
and 1990 (OECD, 1994; CER, 1996). In addition, a major shift is occur-
ring in the composition of municipal waste, with an increase in plastics
and packaging materials.
A large proportion of municipal waste from cities is taken to land-
fills. Tipping, which is the most common method of disposing of urban
wastes in landfills in Europe, is not always controlled. An alternative
system for disposing of municipal waste is an incinerator. In western
Europe it is used, on average, for 20% of produced waste. Incineration
of municipal waste causes a reduction of up to 30% in the weight of the
initial quantities of treated waste and can be designed to recoup the
energy content of the waste. At the same time, this can cause notorious
problems of air pollution, and harmful and toxic waste products. In
addition, it is very costly and extremely difficult to manage (Stanner &
Bourdeau, 1995).
Efforts are now undertaken in many European cities to set an exam-
ple of good practice by recycling, with the aim of reducing the unneces-
sary import of materials as well as the volume of waste that leaves the
city (EEA, 1995).
The present case study concerns the problem of selecting a new
municipality waste treatment system for the city of Turin. At the
moment, a public company called AMIAT manages the municipal
waste through a system of controlled burial. Although the system is
still operational, the problem of finding new technical solutions for the
future will remain after the closing of the current system.
The disposal of urban waste by means of a new landfill raises the
problem of finding suitable new sites with suitable hydrogeological
characteristics, so that this will not add to underground water or soil
pollution. In addition, the landscape can be blighted by unsightly
views and smells during the life cycle of the tip and a considerable
increase in dust, rats, insects and fire hazards may occur. These
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