Environmental Engineering Reference
In-Depth Information
During the Balkan War in 1999, strategically important targets were destroyed,
but also collateral damage (e.g., treatment facilities for waste and wastewater, fer-
tilizer plants) was of importance. Regardless of the nature of the targets, a release
of hazardous substances into the environment, particularly into the soil, had to be
expected. Furthermore, attention must be paid to unexploded bombs and landmines
indicating a serious redevelopment problem. In agricultural land, a rapid refill of
bomb craters with distinct and partly unknown materials had to take place in order
to grow staple food crops. A single 500 pound explosive bomb is able to cause a
bomb crater up to 14 m wide and 9 m deep. No one knows the number of bomb
craters in European countries resulting from the Second World War, but most of the
craters were refilled rapidly without any knowledge about the materials that were
used. The number of these craters could be high. For instance, it is assumed that in
the Indochina conflict 25 million craters were caused by air raids (Genske 2003 ).
The frequency of technogenic materials occurring in deposited soils (termed
Deposols ) is variable, but some general principles are possible to report. The
frequency decreases with increasing distance from the urban agglomerations, in par-
ticular city centres. Nevertheless, even in the countryside former excavated areas
had been refilled with anthropogenic materials in order to level the soil surface or to
improve the physical soil quality in wetlands, for construction purposes. Therefore,
deposited soils that contain transported technogenic materials from other sites far
away can be present in almost every area.
Considering the soil inventory of the German city of Muenster (Fig. 2.3 ), soils
in the city centre as well as in industrially and administratively used areas reveal
a lot of deposited materials, while garden soils dominate the residential areas, and
particularly allotments. Furthermore, soils from deposited material can be found in
parks (refilling processes after the Second World War) and sports fields consisting of
man-made, compacted soils to enable sports activities (Meuser 2007 ). Craul ( 1992 )
reported that in the U.S. capital Washington D.C., located in a coastal area, approx-
imately 81% of the area is disturbed and 14% must be classified as fills. A park
soil survey in the city of Hamburg, Germany, showed 26.5% deposited soils, 26.5%
containing natural material and an additional 20.5% with a mixture of both natural
and technogenic material (Däumling 2000 ). In the city of Stuttgart, Germany, 53%
of the upper 100 cm of the systematically investigated soil revealed more or less
technogenic ingredients (Stasch et al. 2000 ).
In parks and lawn areas that surround houses, often beautifully landscaped with
flowers and ornamental shrubs, deposited soils may only be covered by a thin humic
topsoil layer. In parks of Washington D.C., the thickness of the humic top soils range
between 6 and 35 cm (Craul 1992 ). It is easier to understand that contaminated
sites are associated with derelict and abandoned areas. These areas are normally
recognisable by visible ecological and social impacts such as unvegetated soils, sub-
sidence, ruined buildings, absence of infrastructure, unsightly neighbourhood, and
poor housing, respectively.
The example of man-made, compacted soils on the sports fields, mentioned
above, demonstrates the different soil functions found in urban areas. Apart from the
natural functions of soil, such as providing a medium for plant growth, a recycling
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