Legal and environmental context


Legally, the rejection of chemical pollutants in the clear or sewage waters is prohibited in Switzerland*1, but due to a lack of available solutions this law has thus far not been applied. Today, the surveys of surface water quality, which were financed by different cantons, have revealed the extent of the problem. As solutions are available now, several federal (FOAG and FOEN) and cantonal (departments for the protection of waters and agricultural departments) organisations are trying to develop a common strategy to solve this problem. Some producers and managers of green spaces have already assumed their responsibility and adapted their phyto-pharmaceutical practices and have installed biobed systems. If everyone possessed such a system, the pollution of the surface waters with these products could be reduced by 50 to 90%*2.


In and outside of Switzerland, numerous cultivated or natural soils are threatened by phenomena, such as acidification, salinization, compaction, erosion and pollution. As these modifications cause biological depletion and can even lead to its sterility, many agronomes demand a reorientation of the agricultural practices, thus assuming a certain part of the responsibility concerning this problem.

The qualitative protection of the soils is anchored in the Swiss legislation*3 and its implementation is controlled by the order on the pollution of the soils (Osol). The latter tries to guarantee the fertility of the soils in the long term due to different recommendations and measures. It appoints a frame for the evaluation of the biological, chemical and physical disturbances of the soil, even if until today it treats essentially the chemical disturbances. For the physical and biological impairments, the Osol does not propose any reference values and thus cannot order measures in the event of overstepping.

However, on certain construction sites the impact is examined*4 in order to limit the physical and biological degradation of the relocated or manipulated soils. Therefore, precise measures are determined that have to be planned and supervised by a construction site’s soil supervisor, who is accredited by the Swiss soil science society. Furthermore, a technical document has recently been submitted by the departements for soil protection of different cantons*5, in order to facilitate and standardize the measure of soil compaction, what in the long term could lead to an updating of the Osol.

Concerning the erosion, the Osol determined that the producers must not exceed a value of erosion between 2 and 4 tons of dry soil material per ha and year, depending on the depth of the soil. In order to achieve this, they have to adopt appropriate rural engineering and farming techniques.

Concerning the biological disturbances, which are more complex to characterize, the different implied actors have not yet defined biological indicators that allow a definition of suitable measures. However, certain measures that reinforce the biological activity of the soils are recommended since several year by the proof of ecological performance (PEP).

*1 : EPA Art.28 ; Water Protection Law Art. 1, 3, 6 and 7 ; WPO Art. 8 and 10 ; ChemO Art. 71 b

*2 : De Wilde, T., Spanoghe, P., Debaer, C., Ryckeboer, J., Springae D. and Jaeken, P., 2007. Overview of on-farm bioremediation systems to reduce the occurrence of point source contamination. Pest Management Science. 63, 111-128.

*3 : EPA Art. 7 , 33, 34, 35

*4 : Ordinance on Environmental Impact Assessment

*5 : AG, AI, AR, BE, BL, BS, FR, GE, GR, JU, LU, NE, NW, OW, SG, SH, SO, SZ, TG, TI, VD and ZG