In Switzerland - as in other countries - nitrogen emissions due to human activities lead to problems of water, soil and air pollution.

Some of this pollution  spreads via the Rhine to the North Sea: in coastal and estuarine waters with limited or no connections to the open sea, excessive nutrient inputs may cause eutrophication, which is considered to be one of the main factors contributing to the alarming levels of pollution of the marine environment. It also has adverse effects on human health and on the use of coastal areas for recreational purposes.

OSPAR strategy

As a result of the clear signs of overfertilization that emerged in the 1980s, the countries bordering the North Sea and the International Commission for the Protection of the Rhine (ICPR) agreed to reduce nitrogen and phosphorus inputs into the North Sea by 50% between 1985 and 1995 (OSPAR strategy).

As a member of the ICPR, Switzerland undertook to take appropriate measures to achieve this target. An evaluation conducted in 1995 indicated that, unlike for phosphorus, the 50% reduction target for nitrogen had been missed by a substantial margin. 

Federal Nitrate Strategy

With the aid of a national programme for the reduction of nutrient inputs to water, including a combination of measures in the areas of agriculture, air pollution control and wastewater management, together with ICPR-related efforts, Switzerland should manage to achieve the goals set by the OSPAR Convention.

In the wastewater management sector, the cantonal authorities have prepared plans to reduce the amount of nitrogen discharged from wastewater treatment works in the Rhine catchment area below the lakes by 2,600 tonnes in 2005, compared with 1995 levels. The facilities specified in these plans are required to implement nitrogen removal by no later than 2005.

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