Nitrates

Overview

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 fertiliser and manure enter groundwater through leaching and reach surface water through runoff from agricultural fields.

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 affects natural ecosystems, leading to the depletion of oxygen in water, a phenomenon known as eutrophication, which has negative consequences for biodiversity, fisheries and recreational activities.

Animal manure on the field — © Yevhen Smyk | Getty Images

Background

The Nitrates Directive (Council Directive 91/676/EEC) is one of the EU’s earliest legal frameworks dedicated to protecting water quality from environmental degradation.

It applies to all water types across the EU, including groundwater, surface freshwaters, and saline waters, and focuses specifically on preventing nitrate pollution from agricultural sources.

It requires Member States to monitor waters systematically, designate Nitrates Vulnerable Zones (NVZs) for land draining into polluted waters, and implement action programmes that enforce good practices for the application of fertilisers and manure to land.

Why do we have this law?

The directive was born in 1991 out of growing alarm over the ecological and public health impacts of post-war intensive farming. The explosive growth in livestock densities and synthetic fertiliser use had triggered widespread eutrophication (excessive nutrient enrichment causing oxygen-depleting algal blooms) in rivers, lakes, and seas.

At the same time, rising groundwater nitrate levels threatened human health — particularly infants, in whom high exposure can cause methemoglobinemia ('blue baby syndrome').

Alignment with other EU policies

The Nitrates Directive is a foundational pillar of the EU’s broader water protection architecture. It acts as a basic policy for achieving the ‘good status’ targets mandated under the Water Framework Directive and for attaining the objectives of the Marine Strategy Framework Directive.

Strategic basis

On a strategic level, the directive supports the European Green Deal, including the Biodiversity Strategy for 2030 and the EU’s Zero Pollution Action Plan. The Nitrates Directive is essential to the attainment of the EU's nutrient reduction commitments under the UN Global Biodiversity Framework and the objectives of the Water Resilience Strategy.

The directive also contributes to the EU’s Vision for Agriculture and Food by supporting its core aim of making agriculture more sustainable, resilient and environmentally responsible.

Legislation: Nitrates Directive (91/676/EEC)

Status: In force since 12 December 1991

Application date: 20 December 1993

Summary of legislation

Objectives and aims

The objective of the EU's Nitrates Directive is to prevent and reduce water pollution caused by nitrates from agriculture to protect human health and the environment.

What's included in the law?

The Nitrates Directive creates a structured, preventative regime that targets pollution directly at its terrestrial source and is critical to achieving the objectives of the Water Framework Directive. It requires Member States to identify and manage environmental risks using the following framework:

Nitrate Vulnerable Zones (NVZs): Member States must designate NVZs — agricultural lands draining into waters where nitrate concentrations exceed or risk exceeding the legal threshold of 50 mg/l, or which are eutrophic or at risk of becoming eutrophic.
Fertiliser and manure application caps: Within these NVZs, fertiliser should be limited to crop demands and to available nitrogen in the soil. The application of livestock manure is limited to a maximum of 170 kg of nitrogen per hectare per year to prevent nitrate losses.
Good agricultural practices: The law enforces strict farming rules in NVZs (and voluntary guidelines outside). These regulate when and where fertilisers can be spread, prohibiting their use, for example, during winter, on frozen or waterlogged ground, and near watercourses.
Storage: Farmers must build sufficient storage capacity to hold manure safely during months when spreading is banned.
Reporting: Member States must report water quality trends to the Commission every four years.

RENURE

On 9 February 2026, the Commission adopted a targeted amendment of the Nitrates Directive regarding the use of processed fertilising materials derived from livestock manure (RENURE).

Commission Directive + Annex amending the Nitrates Directive as regards the use of certain fertilising materials from livestock manure

Evaluation

On 15 July 2026, the Commission published its first comprehensive evaluation of the Nitrates Directive, covering more than three decades of implementation since its adoption in 1991. The evaluation assesses the performance of the Nitrates Directive against the criteria of effectiveness, efficiency, relevance, coherence and EU added value. It also identified potential for simplification.

The evaluation found that the directive is overall effective and relevant, but identifies scope for smarter implementation.

It is published together with the latest country reports for the 2020–2023 period, which include recommendations to support Member States.

You can find more information on water quality in Member States on the European Environment Agency page.

See here for more details of the evaluation.

Implementation

For more information on the directive's implementation, visit our dedicated page.

Contact

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