River Pollution in Europe by Country
Across the European countries that report data, rivers averaged a biochemical oxygen demand of 2.24 mg/L in 2023 and 0.081 mg/L of phosphate. Organic pollution has fallen by 18% since 2007. This page compares 27 countries on both measures.
Data year 2023 · Source: Eurostat, based on European Environment Agency monitoring data (January 2026)
Map of river pollution in Europe
Darker countries have higher average concentrations in their rivers. Switch between organic pollution (BOD) and phosphate. Grey countries do not report that measure. Select a country to open its page.
River water quality by country
National averages for 2023, ordered from lowest to highest BOD. Select a column heading to sort. A dash means the country does not report that measure.
| Country | BOD in rivers (mg/L) | Phosphate in rivers (mg/L) | Nitrate in groundwater (mg/L) |
|---|---|---|---|
| Slovenia | 0.83 | – | 15.5 |
| Ireland | 1.16 | 0.025 | 12.7 |
| Cyprus | 1.20 | 0.030 | 19.3 |
| Austria | 1.25 | 0.030 | 20.9 |
| Estonia | 1.47 | 0.022 | 7.0 |
| Finland | 1.55 | 0.012 | 4.9 |
| Latvia | 1.57 | 0.020 | 1.8 |
| Croatia | 1.59 | 0.028 | – |
| Germany | 1.82 | – | 22.2 |
| Belgium | 1.93 | 0.194 | 30.0 |
| Lithuania | 1.93 | 0.165 | 5.7 |
| Slovakia | 2.16 | 0.063 | 16.1 |
| Serbia | 2.39 | 0.066 | 9.1 |
| Poland | 2.47 | – | 8.6 |
| Bulgaria | 2.48 | 0.123 | 29.2 |
| Czechia | 2.51 | 0.089 | 19.6 |
| Italy | 2.59 | 0.098 | 18.8 |
| Romania | 3.13 | 0.090 | 15.5 |
| Portugal | 3.14 | 0.036 | 15.7 |
| Spain | 3.34 | 0.547 | 31.7 |
| Kosovo | 12.49 | – | – |
| Denmark | – | 0.053 | 23.9 |
| France | – | 0.060 | 17.5 |
| Netherlands | – | 0.064 | 8.3 |
| Norway | – | 0.003 | – |
| Sweden | – | 0.008 | 2.4 |
| Switzerland | – | 0.021 | 14.4 |
What these measures tell you
Biochemical oxygen demand (BOD)
BOD is the amount of oxygen that microorganisms need to break down the organic matter in a water sample over five days. High values point to organic pollution, usually from sewage, farm run-off or industrial wastewater. They also mean less oxygen is left for fish and other river life.
Phosphate
Phosphate is a nutrient that reaches rivers from fertilisers, sewage and detergents. Too much of it feeds algae, which can choke rivers and lakes and strip oxygen from the water.
Nitrate in groundwater
Nitrate comes mainly from fertiliser and manure that seep through the soil. It is measured in groundwater, which feeds rivers and supplies much of Europe’s drinking water. The EU limit for drinking water is 50 mg of nitrate per litre.
Frequently asked questions
Which European country has the most polluted rivers?
By biochemical oxygen demand, the highest national average in 2023 was in Kosovo (12.49 mg/L), followed by Spain (3.34). By phosphate, the highest was Spain (0.547 mg/L). Not every country reports both measures.
Which country has the cleanest rivers in Europe?
On these two measures, Slovenia had the lowest BOD (0.83 mg/L) and Norway the lowest phosphate (0.003 mg/L) in 2023. These are national averages and say nothing about individual rivers.
Is river pollution in Europe getting better?
It depends on the measure. Across the countries that report data, BOD in rivers has fallen by 18% since 2007, which points to less organic pollution. Phosphate fell until about 2011 and has risen since, and the European average is now 31% higher than in 2007. Trends differ a lot between countries.
Why is there no data for individual rivers?
Eurostat publishes national averages across each country’s monitoring stations. Station-level data exists at the European Environment Agency, but rivers are named and reported differently in each country, so it cannot yet be compared river by river in a reliable way.
About the data. Each figure is a national average across the river or groundwater monitoring stations a country reports to the European Environment Agency. It describes rivers in general, not any single river, and countries differ in how many stations they report. Not every country reports every measure.
Source: Eurostat datasets Biochemical oxygen demand in rivers, Phosphate in rivers and Nitrate in groundwater, updated January 2026. Latest year available: 2023.
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