ISSaR

WATER QUALITY

Last update
19.11.2013

 


Key question

Is the quality of water affecting both aquatic organisms and the use of water in watercourses improving?


Key message

For all water quality parameters that are monitored, there was a long-term decrease in their concentrations in watercourses. Chlorophyll 'a' is the only exception; it shows a signif icant interannual fluctuation which is caused by close relation of this indicator to the course of temperatures in a given year. Environmental quality standards, especially for N-NO3-, cadmium and CODCr, are not being exceeded.

Interannually, there was an increase in concentrations of some quality indicators; slightly for CODCr (by 1.7%), N-NO3- (by 1.1%) and chlorophyll 'a' (by 4.8%). A more significant increase was recorded for total phosphorus (16.6%) and cadmium (19.8%). The situation regarding eutrophication of still and flowing waters is generally unsatisfactory and it is necessary to permanently reduce the burden of water with nutrients, especially compounds of phosphorus.

Overall assessment

Change since 1990

Change since 2000

Last year-to-year change


References to current conceptual and strategic documents and their targets

The basic conceptual and strategic documents concerning the environment focus on comprehensive protection of the quality and quantity of water, preventing deterioration of the water quality and they also support measures which lead to achievement of good status of both water and the related ecosystems. The objective of achieving at least the good status of surface water and groundwater till 2027 is based on the 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 (the Water Framework Directive). The specific objectives and programmes of measures to improve water quality are set out in the River Basin Management Plans that are currently available for 8 basins. The main measures concerning water protection and other measures, which are not related with water protection directly but contribute to its conservation ultimately, are specified in the Program to reduce surface water pollution with hazardous substances and particularly hazardous substances.

This program is valid for the whole territory of the Czech Republic for the period from 1st January 2010 to 22nd December 2013 and it concerns the substances or groups of substances that are hazardous for the aquatic environment (or through it) and are listed in Annex 1 to the Act No. 254/2001 Coll. (the Water Act). An important instrument for water protection from priority hazardous substances is the Directive 2008/105/EC of the European Parliament and of the Council on environmental quality standards in the field of water policy. The standards have to be achieved by the end of 2015.

Diffuse pollution associated with agriculture is also a significant source of pollutants. One of the axes of the National Strategic Rural Development Plan in the Czech Republic in 2007–2013 also deals with protection of the quality of surface water and groundwater sources through measures related to agricultural activities. The Council Directive 91/676/EEC concerning the protection of waters against pollution caused by nitrates from agricultural sources (the Nitrates Directive) is very important with regard to diffuse pollution.


Indicator assessment – graphic part

Chart 1: The proportion of profiles at which limit values for indicators of permissible pollution of surface water bodies were exceeded, the Czech Republic [%]
Source: The Czech Hydrometeorological Institute

Profiles with exceeded limit values of permissible | pollution of surface water bodies, CZ

 
Key:
__
 3,8 mg/l BOD5
__
 0,15 mg/l Ptotal
__
 20 KTJ/ml FCOLI
 
    __
 25 mg/l CODCr
__
 25 µ/l AOX
 
    __
 4,5 mg/l N-NO3-
__
 0,3 µg/l Cd
 
 
 
Note:
The percentage of profiles within the Eurowaternet network that exceeded the corresponding annual average general requirements for the limit values for indicators of permissible surface water pollution pursuant to the methodological guideline to Government Regulation No 61/2003 Coll. as amended by Government Regulation No 229/2007 Coll.
 
Data:

Chart 2: The concentrations of the pollution indicators of watercourses, the Czech Republic [index 1993=100]
Source: The Czech Hydrometeorological Institute

The concentrations of the pollution indicators of watercourses, the Czech Rep.

 
Note:
The indices for individual indicators against the selected base year were calculated on the basis of arithmetic means for each year using annual average values for 69 selected profiles within the Eurowaternet network and the number of stations for the different years and different indicators change depending on the availability of data. The water quality assessment for BOD5, CODCr, N-NO3- and Ptotal were carried out for the period 1993–2012, most frequently for a set of 68 stations.
 
 
Data:

Chart 3: Average nitrate concentrations in the rivers, the Czech Republic [mg/l]
Source: The Czech Hydrometeorological Institute

Average nitrate concentrations in rivers, the Czech Rep.

 
Note:
The annual mean concentrations for 65–73 (according to data availability) CZ Waterbase-River stations were averaged.
 
 
Data:

Chart 4: Average total phosphorus concentrations in the rivers, the Czech Republic [mg/l]
Source: The Czech Hydrometeorological Institute

Average total phosphorus concentrations in rivers, the Czech Rep.

 
Note:
The annual mean concentrations for 65–73 (according to data availability) CZ Waterbase-River stations were averaged.
 
 
Data:

Chart 5: The concentrations of the pollution indicators of watercourses, the Czech Republic [index 1998=100]
Zdroj: The Czech Hydrometeorological Institute

The concentrations of the pollution indicators of watercourses, the Czech Rep.

 
Note:
The indices for individual indicators against the selected base year were calculated on the basis of arithmetic means for each year using annual average values for 69 selected profiles within the Eurowaternet network and the number of stations for the different years and different indicators change depending on the availability of data. The water quality assessment for AOX (29–61 stations), Cd (42–58 stations), FC (62–69) was carried out for the period 2000–2012.
 
 
Data:

Figure 1: A comparison of water quality in the watercourses, the Czech Republic, 1991–1992 (upper image) and 2010–2011 (lower image)
Source: The T.G. Masaryk Water Research Institute

A comparison of water quality in the watercourses, CZ, 1991–199

A comparison of water quality in the watercourses, CZ, 2007–2008

 
Key:
__
 I. a II.: Unpolluted and slightly polluted water
__
 IV.: Heavily polluted water
 
    __
 III.: Polluted water
__
 V.: Very heavily polluted water
 
 
Note:
Methodology for the map: Traditionally, surface water quality is classified into 5 categories (shown in legend above). The basic classification for the maps below is the aggregate of the following indicators: BOD5, CODCr, N-NH4+, N-NO3-, Ptotal and the and saprobic index of zoobenthos (the final class is the worst class of these indicators).
 

Table 1: Categorization of the profiles of Czech surface waters and groundwater sites on the basis of the time required for overall reduction of the nitrate concentration below a level of 50 mg/l, 2007
Source: Czech Hydrometeorological Institute, Agriculture Water Management Administration (Report of the Czech Republic according to Council Directive 91/676/EEC, 2008)

 Categorization of the profiles of surface waters and groundwater sites on the basis of the time required for overall reduction of the nitrate concentration below a level of 50 mg/l, CZ, 2007
 
Note:
* Percent of the profiles evaluated
CHMI surface waters monitoring – Czech Hydrometeorological Institute monitoring (river profiles)
AWMA surface waters monitoring – Agriculture Water Management Administration monitoring (smaller watercourses profiles)
 

Chart 6: Comparison of nutrient pollution in watercourses of the Czech Republic and European georegions [mg/l], 1993–2010
Source: EEA

 
Note:
Concentration of nitrate (total oxidizable nitrogen – Finland, Sweden, Denmark; some data such as total oxidizable nitrogen – United Kingdom), orthophosphate (georegions) and total phosphorus (Czech Republic) are used as indicators of nutrient pollution. The database WISE-SoERivers (Version 12) is the data source. Data for the region are calculated as the average of the annual average concentrations at the single monitoring stations and the number of stations is shown in the legend in parentheses. The single georegions consist of the following states: eastern Europe: Czech Republic, Estonia, Lithuania, Latvia, Poland, Slovenia, Slovakia; northern Europe – Finland, Norway, Sweden; southern Europe – Spain; south-eastern Europe – Albania, Bulgaria; western Europe – Austria, Belgium, Switzerland, Denmark, Germany, France, Liechtenstein, Luxembourg, the United Kingdom, Ireland (only for orthophosphates).
 

Indicator assessment – text part

In order to improve the quality of surface water and groundwater it is important to reduce pollution discharged from both point and diffuse and areal sources simultaneously. In the Czech Republic, development of concentrations of the respective indicators1 for the past 20 years was affected mainly by changes related to the amount of discharged waste water, access to wastewater treatment (the proportion of treated waste water, the treatment stages, construction and reconstruction of WWTPs) and the socio-economic and political development (change of industrial restructuring, growing living standard, accession to the EU). Climate conditions of the given year (water content of watercourses, incidence of extreme hydrological phenomena, and annual course of air temperature) play an important role in interannual fluctuations in surface water quality, especially in recent years, when the amount of pollution discharged from point sources does not change significantly. On the regional basis, concentration of industrial activities, existence of old environmental contamination or intensity of agricultural activities are of great importance. At present, diffuse and areal sources of pollution with nutrients, pollution with substances that are difficult to remove and are discharged from point sources, and accidental pollution are the main sources of pollution in surface water and groundwater in the Czech Republic.

During the last 20 years, pollution represented as BOD5 and Ptotal, whose average concentration in 2012 was 44% and 47% of the 1993 values, has been reduced most in watercourses of the Czech Republic. In this period, the concentrations of CODCr and particularly N-NO3- have not decreased so significantly but they still account for only 58% and 85% of the 1993 values.

Reduction of average concentrations of organic pollution in watercourses, which comes mainly from municipal wastewater, is attributable not only to reducing the production of this type of pollution, but also highly efficient removal at wastewater treatment plants. In long terms, of the four above-mentioned indicators, CODCr is the pollution which is produced and subsequently discharged from WWTPs into watercourses in biggest volumes even though efficiency of its removal in WWTPs is very high (94.6% in 2012). The efficiency of BOD5 removal is even higher (98.1%). In 2012, the final concentration of CODCr in the Czech Republic’s watercourses reached 17.81 mg/l and that of BOD5 2.7 mg/l, and there was no interannual change in concentrations.

In long perspective, the average concentration of total phosphorus has also declined; in 2012 it was 0.15 mg/l in watercourses. The reason for this positive trend consists in the fact that a big part of phosphorus comes from point source pollution which goes through treatment and the volume of which is generally reduced. The decline in phosphorus inputs was further supported by restrictions concerning the use of phosphates in laundry detergents beginning from 2006; in the last years, application of phosphate fertilizers in agriculture has also been declining. Nonetheless, a substantial part of phosphorus comes from diffuse pollution sources (fertiliser use on agricultural land) at present and this type of pollution is very difficult to remove. Phosphorus pollution from agricultural sources is avoided by good agricultural practice based on the GAEC principles. Pollution from areal sources is complicated by the fact that pollutants are captured in soil and their release with rainwater washout takes place slowly. Phosphorus remains being the major factor to cause eutrophication. Further reduction of phosphorus concentration in surface water is held back by relatively high limits for waste water discharge and the fact that only larger wastewater treatment plants are obliged to remove phosphorus. Although there has been an increase in its concentration in the last two years, this value is still below the long-term average for the years 1993–2012. This is caused by not only the application of phosphate fertilisers but also the growing popularity of dishwashers which are in about one-third of Czech households and which use detergents containing phosphorus. The regulation of phosphates in dishwasher detergents will be valid as late as in 2015.

The concentration of nitrate nitrogen in watercourses has not decreased significantly compared to the other indicators and since 2003 has a rather fluctuating trend. There was no substantial interannual change; the concentration amounted to 3.13 mg/l in 2012. Along with atmospheric deposition and sewage, nitrogen fertilisers are a significant source of nitrogen, and even though their consumption is much lower than it was before 1990, there has been an increase in their consumption since 2000. Due to a lower average nitrogen removal efficiency (74.8% in 2012) and a higher volume of inorganic nitrogen discharged from point sources, the decrease in pollution of watercourses with this element is not as clear-cut as it is e.g. for phosphorus. Since diffuse pollution generally covers most of the nitrate-nitrogen pollution, the interannual increase of its concentration in watercourses is partially bound to rainfall-rich years. During these years, there is a greater runoff from agricultural land treated with fertilisers, while during a drier growing season, application of fertilizers is limited. The long-term trend in the reduction of nitrate pollution is related, inter alia, also with the reduction of nitrogen emissions from livestock farming (pigs and poultry breeding attenuation).

Areal pollution is a source other pollutants, particularly organic substances from the group of pesticides that threaten not only biodiversity in watercourses and still water but also cause problems in water processing for drinking purposes, especially if the source of water is a watercourse. Because of agriculture, the catchment areas of the rivers Želivka, Sázava, Úhlava and Radbuza belong to regions with a high pesticide burden. The problems of drinking water pollution can be prevented by modernising the water processing plants.

Since 2000, cadmium has recorded the greatest decrease in comparison with the other evaluated indicators in the Czech Republic’s watercourses (by 69.9% to 0.1 µg/l in 2012). Cadmium belongs to hazardous substances and its EQS (0.3 µg/l) almost has not been exceeded in the monitored profiles since 2003 (only 6% of the profiles are above EQS). In long terms, the average concentrations of AOX have been stagnating (21.2 mg/l in 2012) and since 2009 they have been decreasing but the proportion of EQS non-compliant profiles (i.e. above 25 mg/l) is the highest of all indicators (23.5%), right after total phosphorus. The reason consists in the fact that this pollution, originating in e.g. paper and chemical industries, municipal waste water but partially also in natural resources, is difficult to degrade. Concentrations of thermotolerant coliform bacteria (FC) primarily reflect the level of faecal pollution and they are also dependent on climate conditions of the given year (temperature, precipitation). In 2000–2004, the concentration of FC was dropping in the monitored profiles, then there was a period of growth and since 2010 the situation improves again. In 2012, the average concentration of FC was 37.0 CFU/ml in watercourses of the Czech Republic.

The concentration of chlorophyll characterizes the level of primary production in aquatic environment (or eutrophication) and the influence of climate conditions (precipitation, temperature) is of particular importance in this context. It depends mainly on average temperatures and the course rainfall during the year (or during the growing season); the concentrations of chlorophyll 'a' therefore fluctuate interannually. For example, the higher values achieved in 2003 were connected with signif icantly below-average precipitation and above-average temperatures. Similarly, the last two years 2011 and 2012 belonged to those with above-average temperatures. In 2012, there was an early beginning of high temperatures, and despite below-average temperatures in June and July, primary production increased; this was also supported by higher supply of nutrients due to higher summer rainfall. In the profiles monitored in the Czech Republic, the average concentration of chlorophyll 'a' has therefore been fluctuating since 2000 and generally it has not decreased. The value of the year 2012 amounted to 16.9 µg/l, which is above the average for the period
2000–2012 (15.2 µg/l).

In terms of reducing the amount of pollution discharged from point sources, relatively good progress has been made both in reducing the concentrations and in preventing exceedances of environmental quality standards. In 2012, the lowest proportion of profiles which exceed EQS was achieved for N-NO3- (4.5%), cadmium (5.9%) and CODCr (7.5%). On the other hand, the highest were for total phosphorus (32.8%) and AOX (23.5%).

Satisfactory quality of water in the Czech Republic’s watercourses is obvious from a comparison of water quality maps, which are compiled according to summarising assessment of the basic indicators monitored continuously in accordance with CSN 75 7221 since the period 1991–1992. However, it is still possible to record water quality class V in some short sections. Since 2000, there has been primarily a reduction of the sections included in quality class V and an increase of the sections with unpolluted and slightly polluted water. In 2012, total of 6,922 km (12.9%) of watercourses managed by Povodí, State Enterprise were included into the quality classes IV or V. This means that quality class IV or V was achieved for at least one of the indicators monitored. In long terms, quality of several watercourses in South Moravia (Litava, Kyjovka) has been worsened and some sections of the Bílina river and a section of the river Lužnice (below the confluence with Nežárka) have also shown the quality class V. In case of the Moravian watercourses it is related to intense agricultural activities; the river Bílina, on the other hand, is a watercourse with a heavy anthropogenic burden (significant pollution with municipal and industrial waste water). The river Lužnice is burdened with municipal pollution and intensive fishing.

Quality of surface water used for bathing has also been monitored systematically in the Czech Republic. In the Czech Republic, about 260 bathing waters are monitored systematically according to national standards and their quality is assessed in five quality categories. There are interannual changes in the number of sites (160–188 sites) reported to the EU and assessed in accordance with the Directive 2006/7/EC (according to the Directive 76/160/EEC till 2011) and bathing water profiles are also being assessed in five categories. In the 2012 bathing season, 40.5% of bathing water was classified in the best quality category (according to the national evaluation standards); by contrast, bathing was prohibited in 10.4% of the sites, which is a 58.8% increase compared to the year 2011. The reason consists in above-average temperatures in the summer months (especially August) which supported the development of cyanobacteria and faecal pollution also played a role. According to the EU assessment standards, 75.0% of bathing water was included in the best category, i.e. excellent water quality.

In the international context it can be concluded that in 1993–2010 there has been a signif icant decrease in concentration of phosphorus (i.e. orthophosphates) in rivers of all regions monitored in Europe. This positive development is mainly brought about by implementation of national and European legislation aimed at reducing pollution discharged in municipal waters, and by introduction of phosphate-free detergents on the market. On average, the lowest concentrations of phosphates are recorded in the rivers of northern Europe; the highest concentrations are in the southern and south-eastern Europe in recent years, where there is a lower percentage of WWTPs with tertiary treatment. The situation regarding eutrophication of flowing and still waters in the Czech Republic continues being unsatisfactory within European comparison and it is necessary to go on reducing the burden on water with nutrients, especially compounds of phosphorus. Pollution with nitrates has not recorded such a significant decline; in the South of Europe, there was even a great increase in this type of pollution. The highest level of nitrate contamination has been recorded in the rivers of Western Europe. The pollution reaches the levels recorded in watercourses in the Czech Republic. The reason consists in the concept of intensive agricultural production and agriculture is therefore the largest contributor to nitrate pollution in the whole of Europe and the Czech Republic.

1 Development of a watercourse’s quality is assessed within the indicator on the basis of average annual concentrations of eight selected basic indicators of pollution for selected Eurowaternet profiles. Organic pollution is expressed by BOD5, CODCr and nutrients are represented by N-NO3- and P . Chlorophyll was selected as a biological indicator and cadmium as a heavy metal indicator, adsorbable organohalogens (AOX) represent the general indicators and thermotolerant (faecal) coliform bacteria (FC) belong to the microbiological indicators.


Data sources

Czech Hydrometeorological Institute
T. G. Masaryk Water Research Institute (a public research institution)
Ministry of Agriculture
European Environment Agency (EEA)


Links to additional information

The European Environment Agency, international indicators (CSI 019, CSI 020)
Report on the state of Water Management in the Czech Republic
IS ARROW – The Czech Hydrometeorological Institute

 

MP CENIA HM

List of indicators by themes