Newsletter and Technical Publications
<International Source Book On Environmentally Sound Technologies
for Wastewater and Stormwater Management>
6. Europe (West)
6.0.1 The countries of Western Europe
The overriding reasons
for the division of Europe into East and West were the availability of
information and the routes to access it, the current situation and practices,
the standards to be met, and the immediate priorities for action. Western
Europe includes all State Members of the European Union plus five non-Member
countries, viz.: Cyprus, Liechtenstein, Malta, Norway, and Switzerland. The
State-Members of the Union make up the bulk of Western Europe. They had a
population of 372 million in 1995. With the other 5 countries, the total
estimated population by the year 2002 will be about 395 million.
Taking the European Union alone, population
density in 1995 was 115 inhabitants/km˛. There were almost 150 million
households, and more than 15 million foreign residents. The Gross Domestic
Product (GDP) was 6192 bn ECU in 1994. Some 55% of the population is actively
employed, of which 5.5% in agriculture, forestry and fishing; 30.6% in
industry, and 63.9% in services. As an average, there are 2.54 person per
household, and in 1994, there were more than 150 million automobiles or more
than 420 per 1000 inhabitants, more than 45000 km motor ways, and a rail
network of more than 150000 km.
6.0.2 The situation at a glance
The region is rich in important river systems some of which are very large.
On the Continent, the rivers are often long
and fed by many tributaries. Large cities and industries are often located
upstream. The most outstanding examples are the Rhine, the Danube, Elbe, and
Oder in Germany, the Warta and Vistula in Poland, the Rhone, Garonne, Loire
and Seine in France, the Ebro, Duero, the Guadiana and the Taco
in Spain, and the Meuse in Belgium and the Netherlands. Several of these rivers
cross one or more international borders and call for concerted international
action, e.g. the Rhine, Danube, and the Meuse. The water pollution and the
consequent effects on water uses downstream are high in most cases.
River systems in England, Italy Norway and Sweden and Finland are comparatively
short. The major polluters are often located near their mouth or close to the
sea, or on estuaries. Yet, in England and Italy, large polluters are also
There are only two sizable lakes in the region, the Lake of Constance and the lake of
Geneva. They both receive Alpine water, are about 350 m deep and have moderate
flowthrough rates. Both receive a fair load of domestic sewage but limited
industrial wastes. The lakes have several riparian states; international
coordination for the management of wastewater and stormwater exists. The
smaller lakes in Switzerland, Germany and France and most of the other
countries are of local and/or sub-regional importance. All pose problems of pollution
both domestic and industrial.
Groundwater is considered a special case in Europe. More than in some other regions of the
world, groundwater is an important source for public, industrial and
agricultural water supply and its protection against pollution is of paramount
importance. The high density of population and industry in some of the
countries poses important threats to groundwater quality.
Water pollution became a public and political priority in the 1950s and 60s in all of
the European countries soon after the reconstruction following World War II was
aggressively initiated. The authorities concerned and the operating agencies
maintain records and statistical information to the best of their capabilities.
Initially, the information was not complete and not of a high reliability,
often spotty and not comparable between countries. Nevertheless, the data
demonstrated that many people were still not connected to sewerage and that the
discharge of the sewage to rivers or lakes was generally unsatisfactory.
Perhaps one third of the sewage collected in communal systems was discharged
without any treatment. Of the remainder, perhaps half was treated by
sedimentation and the rest by biological methods, often trickling filters.
Activated sludge treatment was the exception rather than the rule.
The Commission of the European
Communities and the former Committee of Mutual Assistance in Eastern Europe
promoted improved monitoring and recording of information.
But full European cooperation in wastewater
management was not possible until the late 1980s. Since then, surveys
concerning wastewater management and water pollution control were undertaken as
part of comprehensive studies of the European environment, i.e.:
- The so-called Environmental Performance Reports
by the OECD and the ECE. They examine the burden and the control of pollution
in air, water and other environments, policy and legislation, administration
and international cooperation. Fourteen such reports were available as of 1998.
- The so-called "Assessments" of a wide range of environmental conditions,
including those of inland waters. The First Assessment was compiled jointly
by the European Commission, the ECE, the OECD and WHO, and published in 1995
(EEA 1995). The Second Assessment was published in 1998 by the European Community
(EEA 1998); the underlying information was compiled jointly by Eurostat and
the newly established European Environment Agency (EEA). The third report
was published by the EEA in 1999 and is entitled "Environment in the
European Union at the turn of the Century" (EEA, 1999).
From the above review it will be understood that Europe-wide information on
wastewater management is gradually becoming "harder" though the information
is still variable and incomplete, and in some cases confusing. The Second Assessment
referred to above contains information of considerable interest: it shows that
the percentage of the population served by wastewater treatment varies from
about 50% in the Southern to about 80% in the Northern and Western countries.
It concludes that wastewater treatment has improved in many countries during
the past 10 to 15 years, especially in the South of Europe where the backlog
was large. A larger proportion of the population has been connected to treatment
plants and the treatment level has changed. There has been a pronounced change
from primary to secondary treatment and with it, a substantial reduction of
the organic degradation of European rivers. Moreover, in Western and Northern
Europe, the introduction of tertiary treatment, usually with phosphorous removal,
has grown substantially in the past decade.
It is also observed in the Second Assessment that in the majority of the European
cities, wastewater is still collected together with rainwater and discharged to
water bodies and, accordingly, that eutrophication resulting therefrom is
particular severe in urban estuaries where the input form cities is large. For
instance, the Baltic Sea receives the effluents of more than 70 million people
and from their industrial and commercial activities, and is showing increasing
signs of stress.
6.0.3 Lessons of the past
Western Europe of the
Nineteenth Century was the cradle of todays technology and organizational
approach for the management of waste water and stormwater, while, of course,
many much earlier examples of sewerage, and stormwater disposal have been
recorded as part of the history of the great ancient cultures and city states
of the Far and the Middle East and the Mediterranean. Yet, in the case of
Europe, it was the combined effect of urbanization, industrialization and
enlightened local and central governments which not only called for action but
also enabled the planning and implementation of projects of hitherto unknown
magnitudes in the terms of the size of the population served, public health
purpose, water pollution control and environment protection.
Area-wide drainage systems were introduced in England
during the second half of the Nineteenth Century. They became indispensable
following the rapidly increasing use of the water flush toilette. They relieved
the city of its stormwater and sewage without the nuisances created by the
discharge of foul water in open street drains. But they polluted the River
Thames and many others of the English rivers. The emerging industries were
often built on the shore of the rivers and added their own share to water
pollution. British engineers were called to replicate drainage systems in
Continental Europe, e.g. Paris, Hamburg, Vienna, and many others. Soon, water
pollution became a problem with a European dimension.
In 1858, the Local
Government Act prohibited the cities and towns in England to pollute rivers
whenever other uses were thus impeded. Only 3 years later, in 1861, the Act was
amended to the effect that sewage must be purified if otherwise the quality of
rivers was degraded. River Pollution Commissions were established beginning
1868 and 1875. The Rivers Pollution Prevention Act became law. The lesson of
these developments in England, the first country to undergo rapid
industrialization, stipulates that without a political will and legislation,
water pollution from sewage and stormwater cannot be prevented - even today.
Three other lessons emerged from the English experience:
- The most rational method to combat water
pollution was the river basin approach.
- New technologies were needed.
- Industrial liquid discharges needed specific attention.
As regards the
technology for the purification of sewage and industrial effluents, the English
experience is also noteworthy. Soon is was recognized that land disposal of
untreated waste water was not to be recommended. The putrescence of the organic
matter in sewage and industrial waste was better understood as well as its
effects on lagooning and sedimentation.
Research with filtration soon pointed to intermittency and than to biological
treatment. Efforts were made to study chemical methods for coagulation. Among
the most important developments was the research to measure and estimate the
pollution load originating from a population, its composition and its
environmental effects. Today, this sounds trivial. But before the turn of the
Century, and for some time thereafter, this type of information was lacking,
and the construction of sewage treatment plants were subject to many
The first steps
towards today´s sewage treatment technologies involved the invention of
methods, and often machinery, for the removal of grit and settleable solids.
Only thereafter, was the digestion and the drying of sewage sludge given the
same degree of attention. Many designs were tried, often on a large technical
stage. Some of the designs involved structures combining sedimentation in an
upper chamber and the anaerobic digestion in a lower chamber. A breakthrough
was the invention of the Imhoff tank by Karl Imhoff in 1906, a design adopted
throughout the World .
Next on the agenda
were filtration, bio-filtration and trickling filters. Chemical coagulation was
tried but generally not found satisfactory at the time. In 1914, Lockhett
invented the activated sludge process.
During the last 150
years, many things have changed, i.e. the problems, the scientific base, public
perception and priorities, the amount money and other resources available for
the proper management of waste water and stormwater, the availability of
trained personnel, and technology itself and its cost.
There are many other
lesson to be learnt from the European experience with respect to the gradual
extension of wastewater and stormwater systems from the bigger cities and towns
to the smaller communities; the evolution of the environmental standards to be
met, especially now that much progress has been made in the reduction of the
organic load discharged into rivers after biological treatment of the
wastewater; the reconstruction after World War II; the handling of industrial
wastes; the best ways of reducing stormwater overflows; the effectiveness and
efficiency of treatment technology; standardization; surveillance; and, ultimately,
operation and maintenance and the training of the many personnel needed for the
planning, implementation and operation of wastewater and stormwater systems.
A unique lesson offered by Western Europe
relates to wastewater management in the context of the integration of Europe
and the role of the European Union (EU). While perhaps not of immediate and
direct application to the developing countries, this lesson is nevertheless
relevant in many ways. It is therefore discussed in some detail throughout this