Nutrients in water bodies in the EU-27

Methodology

Annual mean concentrations are used as a basis in the indicator analyses. The aggregation to annual mean concentrations is done by the EEA, unless the country has reported aggregated data only.

Automatic quality control procedures are applied both to the disaggregated and aggregated data, excluding data failing the tests from further analysis. In addition, a semi-manual procedure is applied, focusing on suspicious values having a major impact on the country time series and on the most recently reported data.

Only complete series after inter/extrapolation are used. This is to ensure that the aggregated time series are consistent, i.e. including the same sites/groundwater bodies throughout. Inter/extrapolation of gaps up to 3 years are allowed, to increase the number of available time series. At the beginning or end of the data series missing values are replaced by the first or last value of the original data series, respectively. In the middle of the data series, missing values are linearly interpolated. The selected time series are aggregated to EU-27 level by averaging across all sites/groundwater bodies for each year.

For more information see supporting information here: https://www.eea.europa.eu/ims/nutrients-in-freshwater-in-europe

Units

River nitrate chart:  milligrams of nitrate-nitrogen per litre (mg NO3-N/l)

Groundwater nitrate chart: milligrams of nitrate per litre (mg NO3/l)

River phosphate chart: milligrams of phosphate-phosphorus per litre (mg PO4-P/l)

Lake total phosphorus chart: milligrams of phosphorus per litre (mg P/l)

Additional information

River nitrate chart. The number of river monitoring sites included per country is given in parenthesis (2000-2020): Europe (1182), Austria (41), Belgium (34), Cyprus (14), Czechia (22), Denmark* (38), Estonia (36), Finland** (70), France** (241), Germany (122), Ireland** (17), Italy (25), Latvia (16), Lithuania (22), Poland (16), Romania (89), Slovakia (8), Slovenia (8), Spain** (250), Sweden* (113).

Groundwater nitrate chart. The number of groundwater bodies included per country is given in parenthesis (2000-2020): Europe (954), Austria (14), Belgium (37), Bulgaria (40), Cyprus (6), Czechia (64), Denmark (4), Estonia (18), Finland** (8), France (437), Germany (175), Ireland (66), Italy (10), Latvia (15), Malta (2), Portugal (10), Slovakia (16), Slovenia (6), Spain (26).

River phosphate chart. The number of river monitoring sites included per country is given in parenthesis (2000-2020): Europe (870), Austria (41), Belgium (28), Bulgaria (53), Croatia (23), Czechia (10), Denmark (40), Estonia (37), Finland (67), France (240), Ireland (11), Italy (18), Latvia (16), Lithuania (22), Romania (88), Slovakia (6), Slovenia (10), Spain (47), Sweden (113).

Lake total phosphorus chart. The number of lake monitoring sites included per country is given in parenthesis (2000-2020): Europe (335), Austria (27), Belgium (1), Bulgaria (1), Croatia (3), Denmark (5), Estonia (8), Finland (168), France (1), Germany (6), Lithuania (3), Netherlands (6), Poland (9), Slovenia (3), Sweden (95).

* All data total oxidised nitrogen

**  Some data total oxidised nitrogen