Geoscience Reference
In-Depth Information
What were the effects of this massive transformation on the environment, how
did it change urban metabolism? For reasons of practicality and economy in most
cities the sewage system was implemented as a
“
mixed
”
or
“
combined
”
system,
where all
uid wastes and rain water coming down in a city were to be collected in
a single system. Moving solid feces in the tubes needed large quantities of water as
a carrier, so besides the water
ushed down the water toilets, rain water was quite
welcome to
ush through the tubes and prevent solid fecal matter from getting stuck
inside. Originally Chadwick had envisaged a recycling system: after being collected
and transported out of the city, the waste waters would be dispersed on land outside
the city and the nutrients contained in the waste water would fertilize the soil thus
improving agricultural yields. This arrangement, highly plausible under the aus-
pices of a threatening food shortage in the early 19th century, was to counter
arguments advanced by agricultural chemists such as Justus von Liebig who
warned against robbing the soil of its necessary dung by building sewers. However,
in most cities such a system of sewage farms was not implemented, either because
of lack of suitable land
or
because other cheaper solutions were at hand such as the dumping of waste waters
into rivers and the sea. In London as well as in Hamburg, two cities where sanitary
systems had been set up fairly early, the discharge into the river was preferred
which led to considerable pollution downstream.
55
On the input side of urban
metabolism, the modern sanitary systems brought a massive increase in per capita
demands of water. Up to mid-19th century 15
—
only sandy soils quali
ed well for this practice
—
20 l per inhabitant and day had
-
normally been suf
ll the water needs of urban dwellers. With the water
closet in place and an increasing range of water-consuming amenities
cient to ful
lling houses
200 l per day.
56
Cities, particularly larger cities thus could no longer rely on their local water
resources but had to bring water from further a
and apartments, daily per capita consumption jumped to 150
-
eld, tap into water resources of
distant and frequently rural regions. Paris under Haussmann built impressive
aqueducts which transported water from tributaries of the Seine at a distance of over
200 km.
57
Thus, whereas cities became cleaner, epidemics such as cholera and
pandemic diseases such as typhus were checked, The overall environmental effects
of the
which undoubtedly took place in the later 19th and
early 20th century, were to externalize pollution, to transfer much of the dirt to the
periphery, to pollute the land of sewage farms, rivers and the sea with the
'
cleaning up of cities
'
lth
of urban populations and to massively increase water extraction from far away,
frequently with considerable ecological as well as social consequences. These
consequences could be even more pronounced in arid regions of Europe or in those
parts of other continents, where European migrants established modern urban
societies and implemented these sanitation technologies. Thus in Southern Cali-
fornia a very complicated system of water provisioning emerged to provide water
55
Breeze (
1993
) and B
schenfeld (
1997
).
56
Schott, Urbanisierung, Chap. 9.
57
Hall, Cities, 724.
ü
