Contaminated site remediation
Strategies for decontaminating soil,
buildings and landfills
Decontamination of toxic waste
Contaminated sites are turned into valuable assets
Novartis, Roche, Syngenta, Clariant, Lonza: The Swiss chemicals industry is one of the
strongest competitors in the global marketplace. The production of well-known medicines,
additives and other synthetic materials has, in the past, generated waste which was not
disposed of appropriately. Since the 1990s, the chemicals industry and public sector bod-
ies have been examining this residual contamination in great detail, analyzing the content
of the old deposits of toxic waste, monitoring the quality of ground water and putting in
place remediation strategies tailored to each particular site and its issues. A further fac-
tor is that, since 2000, waste from residential areas can no longer be placed in landfills but
has to be incinerated and used to generate energy. The experience gained in this field over
a number of years has led to the creation of a remarkable cluster of specialist companies
which provide professional solutions for managing the disposal of contaminated material.
The need to monitor and clean up landfills containing both residential and industrial and
commercial waste is another challenge to be mastered.
The relatively small land-area available for use in Switzerland is another reason for tackling
chemical pollution with such determination. As a result of strong population growth and in-
creasing demands in terms of living space and residential accommodation, Switzerland has
seen a significant amount of construction activity in recent years. There has also been
a trend to utilizing former industrial sites for new residential and commercial purposes.
However, for that to happen, the brownfield sites have to be examined and decontaminated
– a challenge which a number of experienced Swiss companies are now able to take on.
Swiss companies can offer
the following technologies:
• Risk assessments
• Generation of site maps
• Ecological building consultancy services
• Recycling of construction material
• Decontamination of railway track
ballast, construction bulk material and
• Soil washing equipment
• Decontamination of material polluted
with chlorinated hydrocarbons
• Decontamination of buildings
• Hazardous waste incineration
• Radon measurement
Switzerland is systematically redeveloping its industrial sites, which are often in central locations,
for new and high-value uses. A key part of the process is examining the sites for contamination and,
where necessary, carrying out remediation work.
Cover: Advanced safety technologies are
deployed during remediation of the toxic
waste site at Kölliken/AG.
This page, top left: Decontamination of
the waste disposal site at Bonfol/JU requires
one of the largest self-supporting structures
Top right: The toxic material excavated
from the waste disposal site at Bonfol/JU
is processed and rendered harmless in
Asbestos removal from buildings
The fibrous structure of asbestos makes it an ideal material: pliant, water and fire resistant,
chemically inert and relatively cheap. Those benefits led to huge volumes of asbestos being
used in buildings for decades all over the world. Now it has been established that the milli-
meter long fibers split into minute particles too small to see. If inhaled, they can cause lung,
chest and peritoneal cancer. Overexposure to asbestos in the workplace risks asbestosis.
Switzerland was quick to react to the dangers: the production, sale and import of products
containing asbestos has been banned since 1990. Based in Basel, Switzerland, Carbotech
is highly experienced in asbestos decontamination. The process begins with an assessment
of the building followed by the development of a decontamination schedule which details the
steps to be taken from the remediation concept stage to tendering and contract award. De-
contamination work is then carried out by local contractors, under the direction of Carbotech
experts. This role extends beyond mere supervision of the works and includes final inspec-
tions and sign-off. Over the past 25 years, Carbotech has carried out several thousand build-
ing inspections and risk assessments, including on power stations in China, Chile and Brazil.
The use of asbestos is still permitted in many countries and in others the ban on its use has
only recently been introduced. As a result, demand for Swiss expertise in the correct handling
of asbestos contamination remains strong. Carbotech has been providing expert advice on
the appropriate handling of buildings and building components contaminated with asbestos
for a number of years to businesses both at home and abroad. The company also provides
training in the correct handling of asbestos for companies with high levels of manual labor and
with particular attention devoted to the protection of employees.
Cleaned up gravel from contaminated sites
Recent decades have seen a building boom in Switzerland. The process of creating new
buildings means old ones are demolished, resulting in huge quantities of building rubble and
a shortage of suitable disposal sites. At the same time, there has been an increase in opposi-
tion to opening new gravel pits. These factors led Swiss businesses to develop a process for
creating high-quality concrete using rubble and they have been doing it for a number of years
now. With this experience and constant development, the technologies for separating rubble
and removing contaminants have become more advanced. Eberhard Bau AG, based close
to Zurich airport in Kloten, Switzerland, has developed equipment which ensures that over
90% of demolition material can be re-used in new buildings. What started out as a pioneering
project in 1993 has now become established practice across Switzerland. An interesting
example which illustrates the approach is the current redevelopment of the St. Johann harbor
at Basel on the River Rhine, where the new campus for Novartis is being built.
Joined up thinking on
In Switzerland, more and more sites con-
taminated with CHCs are being discovered.
Chlorinated Hydrocarbons were used ex-
tensively in the last century as solvents for
degreasing metal components, for cleaning
textiles, in processing animal carcasses and
in the paper industry. The widespread use
has left a legacy of contamination which
threatens groundwater supplies. In 2007,
the Federal Office for the Environment re-
sponded by setting up Project Chloronet
to facilitate the exchange of knowledge and
create a hub of expertise on the subject.
Exchanges and information shared via
Chloronet find their way directly into the
practice of research institutes and busi-
nesses. One company which has been
involved in CHC decontamination since
the early 1990s is Geotest, based in Zol-
likofen, Switzerland. The company provides
a full range of support, from testing soil
and ground water to historic investigations,
analysis, and the development and man-
agement of the remediation plan. Geotest
has been involved in over 500 deconta-
mination projects, with a quarter of these
including CHCs. Although the compounds
are difficult to tackle, intervention is crucial
since the presence of even small quantities
in groundwater can lead to toxic effects.
This page, top left: Eberhard Bau AG is re-
developing the St.Johann harbor in Basel which
will become home to the Novartis Campus.
Top right: The decontamination process at the
toxic waste site in Kölliken/AG involves analyzing
the different hazardous substances removed and
ensuring that each is disposed of appropriately.
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High-tech solution for toxic legacy
What happens to toxic waste which has
been stored underground for decades?
How can you safely recover and dispose
of poisonous material? Switzerland can
provide an answer as it is currently using
leading-edge technology to clean up
a hazardous waste landfill in Kölliken where
475,000 tons (300,000 cubic meters) of
toxic material were deposited by the Swiss
cantons of Aargau and Zurich, as well as
the chemical industry in nearby Basel,
between 1978 and 1995.
Work to secure and analyze the waste has
been on-going since 1996. Three air-tight
halls were constructed over the site and
any potentially contaminated fumes are
passed through activated charcoal filters
to avoid any danger for the tightly popu-
lated surrounding area. Drainage systems
have been installed to prevent seepage into
ground water. Contaminated water is pro-
cessed via a specially-designed plant. Op-
erations to systematically excavate, analyze
and dispose of the material, which is loose,
in barrels or in bags, started in 2007, and
to date 158,000 tons have been removed.
Recovery of the buried material is due to
complete by 2016, with the base of the
landfill then examined for contamination.
Only when it is clear that no hazardous
residues are present, will the site, which is
situated in the middle of a residential area,
The total costs of the clean-up operation
are likely to be 980m US $. On the upside,
a number of Swiss companies have been
able to demonstrate their capabilities and
develop ground-breaking approaches.
That expertise is in demand around the
world and, in future, thousands of hazardous
waste sites all around the globe will have
to be decontaminated and made available
for new purposes.