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Protecting waters against pollution caused by nitrates from agricultural sources


Nitrogen is a crucial nutrient that helps plants and crops grow, but high concentrations are harmful to people and nature. Pure, clean water is vital to human health and to natural ecosystems. Excess nitrogen from agricultural sources is one of the main causes of water pollution in Europe.

Nitrates and organic nitrogen compounds from fertilizer and manure enter groundwater through leaching and reach surface water through runoff from agricultural fields. A high level of nitrate makes water unsuitable as drinking water.

In rivers, lakes and marine waters, nitrogen and other nutrients, in particular phosphorus, stimulate the growth of algae. At moderate levels, algae serve as food for aquatic organisms, including fish. However, excessive nutrient concentration in water systems will cause algae to grow excessively. This affects the natural ecosystem and can lead to depletion of the oxygen in the water. This phenomenon, known as eutrophication, has negative consequences for biodiversity, fisheries and recreational activities.

Both phosphorous and nitrogen play a role in eutrophication, but while the main cause of eutrophication in fresh water is phosphorus, it is mainly caused by nitrogen in marine water.


The Nitrates Directive aims to protect water quality across Europe by preventing nitrates from agricultural sources that pollute ground and surface waters and by promoting the use of good farming practices.

The Directive aims to reduce water pollution caused by nitrates used in agriculture by

  • monitoring nitrate concentrations of water bodies
  • designating nitrate vulnerable zones
  • establishing codes of good agricultural practices and measures to prevent and reduce water pollution from nitrates

In the EU

€70 billion
annual cost of nitrogen losses
agricultural nitrogen input to aquatic systems caused by livestock production
ammonia emissions from agriculture to atmosphere caused by livestock production


The Nitrates Directive requires EU Member States to monitor the quality of waters and to identify areas that drain into polluted waters or at risk of pollution. These concern waters that due to agricultural activities are eutrophic or could contain a concentration of more than 50 mg/l of nitrates. Those areas are defined as Nitrate Vulnerable Zones (NVZs).

The Nitrates Directive forms an integral part of the overarching Water Framework Directive and is one of the key laws protecting waters against agricultural pressures.

Evaluation of the Directive

The Commission has launched a public consultation on the evaluation of the Nitrates Directive. Interested parties such as farmers, industries, NGOs, citizens, public administrations, water authorities and others are invited to share their views until 8 March 2024. The evaluation will assess if the Nitrates Directive remains fit for purpose. Find out more about the evaluation.

On 19 April 2024 the Commission launched a public consultation lasting until 17 May on a Commission Directive amending Annex III of the Nitrates Directive.


EU countries must:

More information on the aims, implementation and impact of the Nitrates Directive can be found in the Factsheet on the Nitrates Directive, in the Questions and Answers document and on the following infographics:

Monitoring and Reporting

Every four years, EU Member States are required to report on:-

  • nitrate concentrations in groundwaters and surface waters
  • eutrophication of surface waters
  • assessment of the impact of (an) action programme(s) on water quality and agricultural practices
  • revision of NVZs and (an) action programme(s)
  • estimation of future trends in water quality

These four-yearly reports produced by Member States are used as the basis for a four-yearly report by the European Commission on the implementation of the Directive.


For questions about EU environmental policy, please contact Europe Direct.