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You are here: Home / Data and maps / Indicators / Nutrients in freshwater / Nutrients in freshwater (CSI 020) - Assessment published Dec 2010

Nutrients in freshwater (CSI 020) - Assessment published Dec 2010

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Generic metadata

Topics:

Water Water (Primary topic)

Tags:
soer2010 | biodiversity | csi | nitrates | nutrients | freshwater quality | lakes | rivers | water | orthophosphate | thematic assessments | freshwater | phosphorus
DPSIR: State
Typology: Descriptive indicator (Type A - What is happening to the environment and to humans?)
Indicator codes
  • CSI 020
Dynamic
Temporal coverage:
1992-2008
Geographic coverage:
Albania Austria Belgium Bulgaria Czech Republic Denmark Estonia Finland France Germany Hungary Ireland Latvia Liechtenstein Lithuania Luxembourg Netherlands Norway Poland Portugal Slovakia Slovenia Spain Sweden Switzerland United Kingdom
 
Contents
 

Key policy question: Are concentrations of nutrients in our freshwaters decreasing?

Key messages

  • Average nitrate concentrations in European groundwaters increased from 1992 to 1998, and have remained relatively constant since then.
  • The average nitrate concentration in European rivers decreased by approximately 9 % between 1992 and 2008 (from 2.4 to 2.2 mg/l N), reflecting the effect of measures to reduce agricultural inputs of nitrate.
  • Average orthophosphate concentrations in European rivers have decreased markedly over the last two decades, being almost halved between 1992 and 2008 (47 % decrease). Also average lake phosphorus concentration decreased over the period 1992-2008 (by 26%), the major part of the decrease occurring in the first half of the period. The decrease in phosphorus concentrations reflect both improvement in wastewater treatment and reduction in phosphorus in detergents.
  • Overall, reductions in the levels of freshwater nutrients over the last two decades primarily reflect improvements in wastewater treatment. Emissions from agriculture continue to be a significant source.

Average concentrations of nutrients in European groundwaters and surface waters (1992-2008) Fig. 1a: Nitrate in groundwater; Fig. 1b Nitrate in rivers; Fig. 1c Orthophosphate in rivers; and Fig. 1d: Total phosphorus in lakes

Note: Concentrations are expressed as annual mean concentrations. Only complete series after inter/extrapolation are included (see indicator specification). The number of groundwater bodies/river stations/lake stations included per country is given in metadata (see downloads and more info). Fig 1a: Nitrate concentration in European groundwater 1992-2008 Fig 1b: Nitrate concentration in European rivers 1992-2008 Fig 1c: Orthophosphate concentration in European rivers 1992-2008 Fig 1d: Total phosphorus concentration in European lakes 1992-2008

Data source:
Downloads and more info

Key assessment

Nitrate in groundwaters. There was a slight increase in annual mean nitrate concentrations in European groundwaters from 1992 to 1998, followed by a minor decrease.

Nitrate in rivers: At the European level there has been a small decrease in concentrations of nitrate.

Agriculture is the largest contributor of nitrogen pollution, and due to the EU Nitrate Directive and national measures the nitrogen pollution from agriculture has been reduced in some regions during the last 10-15 years, this reduced pressure is reflected in lower river nitrate concentrations.

Phosphorus in rivers. The average concentrations of orthophosphate in European rivers halved over the past 16 years. In many rivers the reduction started in the 1980s. The decrease is due to the measures introduced by national and European legislation, in particular the Urban Waste Water Treatment Directive [4], which involves the removal of nutrients. Also the change to use of phosphate-free detergents has contributed to lower phosphorus concentration.

Phosphorus in lakes. During the past few decades there has also been a gradual reduction in phosphorus concentrations in many European lakes. As treatment of urban wastewater has improved, phosphorus in detergents reduced, and many waste water outlets have been diverted away from lakes, phosphorus pollution from point sources is gradually becoming less important. Agricultural sources of phosphorus are still important.

Specific policy question: Are nitrate concentrations in our groundwater decreasing?

Nitrate concentrations in groundwater between 1992 and 2008 in different geographical regions of Europe.

Note: The data series per region are calculated as the average of the annual mean for groundwater bodies (GWBs) in the region. Only complete series after inter/extrapolation are included (see indicator specification). The number of groundwater bodies included per geographical region is given in parentheses.

Data source:

WISE-SoE GW quality (version 10)

Downloads and more info

Specific assessment

Present concentrations per country

See also WISE interactive maps:  Nitrates in groundwater by country

Groundwater nitrate concentrations primarily reflect the relative proportion and intensity of agricultural activity. Although there were no countries where the average groundwater nitrate concentrations exceeded the threshold Groundwater Quality Standard of 50 mg/l nitrates as laid down in the Groundwater Directive (2006/118/EC) [2] in 2008, 13 out of 27 countries had groundwater bodies (GWBs) with average concentration above the standard. Spain, Belgium and Denmark had the highest proportion of GWBs with average concentration above the standard, but there was also a significant number of GWBs above the standard in Germany, Bulgaria, Romania and Portugal. Groundwater nitrate concentrations were generally low (most GWBs < 10 mg/l NO3) in Norway, Sweden, Finland, Estonia, Latvia, Bosnia and Herzegovina and Serbia.

Trends in groundwater nitrate concentration (see also Fig. 1)

Looking at individual GWBs there is wide variation in trends, with 21% of the GWBs showing significantly decreasing nitrate concentrations since 1992 (an additional 5% showed a marginally significant decrease), while 24% of the GWBs showed significantly increasing concentrations (an additional 5% marginally significant). The countries with the highest proportions of GWBs with significant decreasing trends are Austria, Latvia and Portugal.

Geographical region time series and trends (Fig. 2)

There is marked variation in groundwater nitrate concentrations between different geographical regions of Europe, with high concentrations in Western Europe and low concentrations in Northern Europe. Overall nitrate concentrations in Western, Northern and Eastern Europe have remained relatively stable since 1992, although there is marked variation between different GWBs.

In Southern Europe (only groundwater data from Portugal) there has been a marked decrease (3 out of 4 groundwater bodies significant decrease). Likewise, Southeastern Europe is only represented by Bulgaria. Here there was a marked increase until 1998, but since then the concentrations have stabilised.

Specific policy question: Are concentrations of nutrients in our surface waters decreasing?

Nitrate concentrations in rivers between 1992 and 2008 in different geographical regions of Europe.

Note: The data series per region are calculated as the average of the annual mean for river monitoring stations in the region. Only complete series after inter/extrapolation are included (see indicator specification). The number of river monitoring stations included per geographical region is given in parentheses.

Data source:

WISE-SoE Rivers (Version 10)

Downloads and more info

Nitrate concentrations in rivers between 1992 and 2008 in different sea regions of Europe.

Note: The sea region data series are calculated as the average of annual mean data from river monitoring stations in each sea region. The data thus represents rivers or river basins draining into that particular sea. Only complete series after inter/extrapolation are included (see indicator specification). Two regions are not shown in the figure due to a lack of data (Barents Sea: 1 station, Norwegian Sea: 2 stations); these stations have NO3 concentrations below 0.8 mg/l N.

Data source:

WISE-SoE Rivers (Version 10)

Downloads and more info

Phosphorus concentrations in rivers (orthophosphate) between 1992 and 2008 in different geographical regions of Europe.

Note: The data series per region are calculated as the average of the annual mean for river monitoring stations in the region. Only complete series after inter/extrapolation are included (see indicator specification). The number of river monitoring stations included per geographical region is given in parentheses

Data source:

WISE-SoE Rivers (Version 10)

Downloads and more info

Phosphorus concentrations in rivers (orthophosphate) between 1992 and 2008 in different sea regions of Europe

Note: The sea region data series are calculated as the average of annual mean data from river monitoring stations in each sea region. The data thus represents rivers or river basins draining into that particular sea. Only complete series after inter/extrapolation are included (see indicator specification). The number of river monitoring stations per region is given in parentheses.

Data source:

WISE-SoE Rivers (Version 10)

Downloads and more info

Phosphorus concentrations in lakes (total phosphorus) between 1992 and 2008 in different geographical regions of Europe.

Note: The data series per region are calculated as the average of the annual mean for lake monitoring stations in the region. Only complete series after inter/extrapolation are included (see indicator specification). There were no stations with complete series after inter/extrapolation in the South and Southeast regions. The number of lake monitoring stations included per geographical region is given in parentheses

Data source:

WISE-SoE Lakes (Version 10)

Downloads and more info

Specific assessment

Nitrate

Present concentrations per country 

See WISE interactive maps: Mean annual Nitrates in rivers

Rivers draining land with intense agriculture or high population density generally have the highest nitrate concentrations. Rivers with nitrate concentrations exceeding 5.6 mg/l N are found predominantly in northwest France, Spain, Belgium and the southeast UK. However, several rivers with concentrations exceeding 3.6 mg/l N are found in many other countries, particularly in the Netherlands, Denmark, Germany, Austria, Ireland, Hungary, Italy, Estonia and Latvia. Rivers in the more sparsely populated Northern Europe and mountainous regions generally have average concentrations less than 0.8 mg/l N.

Trends in nitrate concentration (see also Fig. 1):

Overall there has been a significant decrease in river nitrate concentrations at 29% of the stations (an additional 5% marginally significant), while there has been a significant increase at 16% of the stations (an additional 5% marginally significant). The countries with the highest proportions of river stations with significant decreasing trends are Denmark, the Netherlands, Czech Republic and Germany. Across Europe as a whole, the rate of improvement is still slow, reflecting the continued significance of agricultural nitrogen emissions.

Sea region time series and trends (Fig. 3)
see also map of sea regions
Nitrate concentrations in rivers vary markedly between the sea regions of Europe. The average nitrate concentration in rivers draining to the North Sea is around 2 mg/l N higher than that in rivers feeding the Atlantic Ocean, the Black Sea and the Mediterranean Sea and almost 3 mg/l N  higher than that of rivers draining to the Baltic Sea.

Declining nitrate concentration trends are most clearly observed in the North Sea and Black Sea regions, while there has been a slight increase for the Atlantic Ocean and Mediterranean Sea regions

Geographical region time series and trends (Fig. 4)
There is marked variation in river nitrate concentrations between regions, with Western Europe rivers having 2-3 mg/l higher concentrations than Northern Europe, on average, and the remaining regions being somewhere in between. Except for the increasing trend in Southern Europe, nitrate concentrations are generally decreasing (East, Southeast, West) or fairly stable (North)

Phosphorus

Present concentration per country

See also WISE interactive maps: Mean annual Orthophosphate in rivers & Mean annual Total Phosphorous in lakes

Relatively low concentrations of phosphorus in rivers and lakes are found in Northern Europe (Scotland, Norway, Sweden, and Finland), the Alps and the Pyrenees, predominantly reflecting regions of low population density and/or high levels of wastewater collection and treatment.
In contrast, relatively high concentrations (greater than 0.1 mg/l P) are found in several regions with high population densities and intensive agriculture, including: Western Europe (southeast UK, the Netherlands, Belgium), Southern Europe (Italy, central Spain and Portugal), Eastern Europe (Poland, Hungary), and South-Eastern Europe (Bulgaria, Former Yugoslav Republic of Macedonia, Turkey). Given that phosphorus concentrations greater than 0.1-0.2 mg/l P are generally perceived to be sufficiently high to result in freshwater eutrophication, the observed high values in some regions of Europe are of particular concern.

Trends in phosphorus concentration (see also Fig. 1)

Average concentrations of orthophosphate in European rivers have decreased markedly since 1992, particularly during the first half of this period. At 42 % of the river stations there has been a significant decline in orthophosphate concentration since 1992 (an additional 5 % marginally significant), while there has been an increase at only 6% of the stations (an additional 2% marginally significant).
For lakes there has been a significant decline in total phosphorus concentrations since 1992 at 31% of the stations (an additional 9% marginally significant), while there has been a significant increase at 8% of the stations (an additional 2% marginally significant).
This decrease reflects the success of legislative measures to reduce emissions of phosphorus such as those required by the Urban Waste Water Treatment Directive [4].

Sea region time series and trends  (Fig. 5)
see also map of sea regions.
Orthophosphate concentrations are generally lowest for rivers draining to the Baltic Sea and (after 1999) highest for rivers draining to the Atlantic Ocean. The strongest decrease in orthophosphate concentration is found for rivers draining to the Mediterranean Sea, but the decrease is almost similarly strong in all other regions except the Baltic Sea.
Although the decline is much less in the latter half of the period, there is still a decline going on.

Geographical region time series and trends (Fig. 6)
Northern Europe has markedly lower river orthophosphate concentrations than in the other regions of Europe. The same pattern is seen for lake total phosphorus concentrations (Fig. 7). River orthophosphate concentrations have generally decreased in all regions except Northern Europe, where there was hardly any change. The trend is strongest for Western Europe and least strong for Southeastern Europe

Lake total phosphorus (Fig. 7) shows a similar strong decrease for Western Europe and virtually no trend for Eastern Europe. The trend in lake total phosphorus in Northern Europe is small.

The difference between lake and river data for Eastern Europe is partly caused by the inclusion of a number of Czech stations in the rivers dataset, with predominantly negative trends. In addition there is a stronger decline in Hungarian rivers than lakes, and there has been increasing concentrations in Latvian lakes while there has been a slight decrease for the rivers.

References and links to policy information

[1] The Drinking Water Directive (DWD): Council Directive 98/83/EC of 3 November 1998 on the quality of water intended for human consumption.

[2] Groundwater Directive (2006/118/EC).

[3]  The Nitrates Directive: Directive 91/676/EEC on nitrates from agricultural sources.

[4] The Urban Waste Water Directive (UWWD): Council Directive 91/271/EEC concerning urban waste-water treatment. 

[5] The Water Framework Directive (WFD): Directive 2000/60/EC of the European Parliament and of the Council establishing a framework for the Community action in the field of water policy.

[6] EEA Core Set of Indicators CSI01 Emissions of acidifying substance and CSI05 Exposure of ecosystems to acidification, eutrophication and ozone

 

Data sources

More information about this indicator

See this indicator specification for more details.

Contacts and ownership

EEA Contact Info

Peter Kristensen

Ownership

EEA Management Plan

2010 1.4.2 (note: EEA internal system)

Dates

Frequency of updates

Updates are scheduled every 1 year in July-September (Q3)
Document Actions
European Environment Agency (EEA)
Kongens Nytorv 6
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Denmark
Phone: +45 3336 7100