D-BAUG - Departement Bau, Umwelt und Geomatik - ETH Zürich

Field Trip
Field Trip to Vienna’s Water Supply and Waste Disposal Plant
Organised for the second consecutive year, the study excursion to Vienna’s Water
Supply and Waste Disposal Plant, which is an official course in the Master pro-
gramme, was scheduled from 30 April – 3 May 2009.
by Michael Margreth (MSc Geography) / IfU
and Christian Maslo (Ing. Mag. [MSc in Engineering]), AQUA-PR and senior lecturer at the University of Vienna
Excursion overview
About 30 students studying environmental sciences and
engineering at ETH Zurich, or geography at the University
of Zurich, had the opportunity to visit Vienna’s Water Supply
site, its sewerage treatment plant, units and technical
facilities, as well as its headwaters.
Stop in Vienna, the federal capital (30 April 2009)
During our one-day visit of our eastern neighbours’capital
city, the students had a tour of the sewerage treatment
plant, which was upgraded in 2005. Located to the southeast
of Vienna in Simmering, the 11th Viennese district,
the plant treats the entire effluent of the city’s 1.8 million
inhabitants. With a cleaning capacity of around 96%, this
plant is the most modern of its type In Europe.
In the afternoon, we visited the water tower on Wienerberg
in the 10th Viennese district, “Favoriten”. Built between
1898 and 1899, the tower, which from 1910 was only used
occasionally once the second Viennese mountain spring
water line (German acronym: HQL) came into operation,
was finally closed down in 1956. It is considered as a building
of industrial historicism and is under monumental
protection. The pressure for supplying the surrounding
houses was enabled by the principle of “communicating
vessels”. Most impressive of all, visitors may look around
the originally built technical facilities. In the evening of the
first day of our visit, our entire delegation from Zurich was
invited by the City of Vienna to a reception hosted by the
mayor followed by dinner in the basement of the Viennese
City Hall. Not only was this an ideal opportunity to interact
socially and professionally with our colleagues from the
Viennese water supply works, but our students could also
relish the many delights of Viennese cuisine.
14 ▪ D-BAUG Annual Report 2009
Stop at Vienna’s Headwaters located in the provinces of Lower
Austria and Steiermark (1–3 May 2009)
Vienna’s drinking water supply is largely based on spring
water which, considering its type and quality, is unique
for a city with a population of one million people. Depending
on whether the year was dry or wet, the percentage
of spring water is between 92 to 98%. The remaining 2 to
8 % is groundwater in porous media and comes from
ground water works (Lobau and the third Viennese water
supply line in Moosbrunn). Spring water is extracted in
the east Karst region of the northern Kalk Alps in the provinces
of Lower Austria and Steiermark and is piped to
Vienna via the first and second Viennese mountain spring
water line.With the exception that the Pfannbauern spring
water has to be pumped, drinking water from all the other
springs flows to the Austrian metropolis only with the
help of gravity along the ducts of the first and second
Viennese mountain spring water line. About one sixth of
the Austrian federal territory is covered by landscape shaping
processes which are generally referred to as karst formation.
During our three-day visit of the City of Vienna’s headwaters,
the students were shown different types of springs:
dolomite springs with a relatively constant delivery and
lime springs with high fluctuating delivery.The connection
between spring delivery and karst formation system in
lime or dolomite inside the mountain is crucial. Since, before
seepage in the karst rock, the water is filtered mostly
only through a relatively thinly covered soil layer, the danger
of contamination in the spring water catchment area
is high. For this reason, the protection of the spring water
catchment area – from the plateau to the spring water immersion
points in the valleys – is of major importance.