Indicator Contaminated sites

Contaminated sites

Substances that are dangerous for the environment can enter the environment from landfill, decommissioned industrial plants or accident sites. In Switzerland there are approximately 38,000 such contaminated sites, of which about 13'700 have been assessed for remediation. The current drop in the number of sites requiring investigation is a measure of the progress made so far in the remediation of contaminated sites.

Assessment of the state
good good
Assessment of the trend
unsatisfactory unsatisfactory
requiring remediation: 5% requiring monitoring: 2% requiring investigation: 11% requiring neither monitoring nor remediation: 29% no harmful or unwanted effects: 53%
Contaminated sites in % (end of 2023)

Data for the graph: Excel
Source: FOEN
requiring remediation: 3% requiring monitoring: 5% requiring investigation: 26% requiring neither monitoring nor remediation: 7% no harmful or unwanted effects: 59%
Contaminated sites in % (2010)

Data for the graph: Excel
Source: FOEN

Of the almost 17,800 sites needing investigation, the authorities were able to investigate and classify around 13,700 by the end of 2023. Of these, no further measures were necessary at nearly three-fourths of them. About 700 sites require periodic monitoring and currently a good 1,800 sites proved to be contaminated and require remediation. A comparison between the year 2023 and the year 2010 shows that the number of sites awaiting investigation has fallen significantly. Therefore, the state is assessed as good. If the pace of work cannot be stepped up, the goal of completing the investigations by 2028 will not be achieved. The trend is therefore assessed as unsatisfactory.

The remediation of contaminated sites will be largely finished in around 20 years. This means that over the next few years there will be a continuous reduction in the number of sites needing investigation. At the same time, the number of sites assigned to other categories will increase in the medium term as the sites that have been inspected are definitively classified. In the long term, the number of sites requiring monitoring and remediation will fall until the only sites remaining can be classified either as “no harmful or unwanted effects” or as “requiring neither monitoring nor remediation”.

International comparison

As the site classifications are specific to Switzerland, no international comparisons can be made for this Indicator.


Statistical evaluation of annual data from the registers for contaminated sites at canton and federal level (VBS, BAV, BAZL, FEDRO).

Last updated on: 31.05.2024

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