At a glance
- The European Nitrates Directive places Germany under the obligation to prevent exceedances of the threshold of 50 milligrammes per litre.
- Since 2008, this threshold has been exceeded every year by at least 16.9 % of the measuring points.
- On June 21, 2018, the European Court of Justice found Germany guilty of violating the EU Nitrates Directive (case C-543/16).
- Agriculture is the most important source of high nitrate concentrations in groundwater.
In agriculture crops are given the necessary nitrogen via fertiliser. However, the fertiliser is often not applied correctly for the specific site and use. If the amount of fertiliser is too high the plants do not absorb it completely. Excessive nitrogen is leached out and ends up as nitrate in the groundwater and other water bodies. This leads to eutrophication in rivers and lakes (cf. ‘Ecological status of rivers’ and ‘Ecological status of lakes’ indicators), and to nitrogen enrichment and exceedance of the threshold in ground water.
Nitrate can be converted to nitrosamines in the human body. This can result in disruption to the oxygen transport in infants (methemoglobinemia). The Drinking Water Ordinance therefore stipulates a maximum value for nitrate of 50 milligrammes per litre (TrinkwV 2001).
The threshold is very rarely exceeded in drinking water (cf. drinking water quality, in German only). It is complex and expensive to remove nitrate from groundwater in water treatment plants.
Assessing the development
The aim of the European Nitrates Directive (EU Directive 91/676/EWG) is to prevent the groundwater being polluted by nitrates. Governments are obliged to develop action plans to prevent nitrate concentrations above 50 mg/l. On 21 June 2018, the European Court of Justice found Germany guilty of violating the EU Nitrates Directive. The reason therefore was that the directive had not been implemented adequately and the measures taken so far were not sufficient to achieve a significant reduction in nitrate pollution. Since 2008 the proportion of sampling sites which exceed the threshold value lies between 17 and 19 %. The proportion of sampling sites with a nitrate concentration above 25 mg/l has also stagnated since 2008 at 35-38 %. Since 2016 meeting the nitrate limit has also become part of the German Sustainable Development Strategy (BReg 2016).
The most important instrument for achieving the Nitrates Directive targets is the German Fertiliser Application Ordinance (DüV). This was revised in a long-term process by the Federal Government and adopted in spring 2017. The effects of this new regulation will only become apparent in a few years. However, it is already foreseeable that they alone will not be sufficient to achieve the objectives of the Nitrate Directive.
Germany has to send data on the condition of the groundwater to the European Environment Agency (EEA) on a regular basis. The Federal States therefore selected representative sampling sites to add to the EEA groundwater network. These are reported to the EEA through the German Environment Agency. The indicator compares the sampling sites where the limit value is exceeded with the total number of sampling sites.
More detailed information: 'Grundwasserbeschaffenheit' (in German only).