C10 - BOD and concentration of ammonium in rivers of the Republic of Belarus
Is organic matter and ammonium pollution in rivers in the Republic of Belarus decreasing?
Figure 1 - Rivers – Annual mean biological oxygen demand (BOD) and ammonium concentration (1986-2017)
Data sources:
Data was provided from National Environmental Monitoring System by the Ministry of Natural Resources and Environmental Protection of the Republic of Belarus under the ENI SEIS II East project activities
C10 – Biochemical oxygen demand and concentration of ammonium in rivers provided by National Statistical Committee of the Republic of Belarus
Note: The data series are calculated as the average of annual mean concentrations of BOD5 (mg O2/l) (top), and ammonium (mg NH4-N/l) (bottom) for rivers in the whole of the Republic of Belarus (left) and in different river basins (right) for the period 1986-2017. The total number of rivers is 86.
Biochemical oxygen demand (BOD) and ammonium are key indicators of organic pollution in water. BOD shows how much dissolved oxygen is needed for the decomposition of organic matter present in water. Concentrations of these parameters normally increase as a result of organic pollution caused by discharges from waste water treatment plants, industrial effluents and agricultural run-off. Severe organic pollution may lead to rapid de-oxygenation of river water, high concentration of ammonia and disappearance of fish and aquatic invertebrates. Some of the year-to-year variation can be explained by variation in precipitation and runoff.
The average BOD for the whole of Belarus has decreased since 1992, in particular in the period 1997-1998. Comparing the average of the last three years to that of the first three years of the time series, the BOD has decreased by 19%. The largest decrease is observed in the Western Bug river basin, followed by the Dniepr and Pripyat basins, while there has hardly been any change overall in Western Dvina, the river basin with the lowest BOD levels.
For ammonium the concentration levels have been more variable, but there has been a steady decrease since 1998. This is also seen in all the river basins, but all except Western Dvina experienced a sharp increase in 1998. This is in contrast to the marked decrease in BOD on the same period, and may indicate partly different sources. However, the decreasing levels in both parameters, ammonium in particular, over the last two decades indicates reduced pressure from organic pollution.
What is the current state of organic matter and ammonium pollution of rivers in the Republic of Belarus?
Figure 2 - Rivers - BOD and Ammonium (2017)
Data sources:
Data was provided from National Environmental Monitoring System by the Ministry of Natural Resources and Environmental Protection of the Republic of Belarus under the ENI SEIS II East project activities
C10 – Biochemical oxygen demand and concentration of ammonium in rivers provided by National Statistical Committee of the Republic of Belarus
Note: Distribution of river monitoring sites to BOD5 (left) and ammonium concentration (right) classes in the different river basins (Western Dvina, Neman, Western Bug, Dnieper and Pripyat) of the Republic of Belarus, based on annual average concentrations for 2017. The total number of monitoring sites per river basin is given in parenthesis.
The class system is the same as the one used in the EEA indicator WAT 002- Oxygen consuming substances European rivers. See the indicator specification section there for further information.
Sites with annual average BOD above the lowest national maximum permissible concentration for BOD (3 mg O2/l) in 2017 are found in all river basins except Western Dvina. Still, in all regions the majority of sites were below this level. All over river sites in the Pripyat river basin can be regarded as being in the worst condition, with the highest proportion of sites in the highest category and none in the lowest.
The largest proportion of sites with ammonium concentration above 0.2 mg NH4-N/l was found in the Dnieper, Pripyat and Western Bug river basins. Only 14% of the sites had ammonium concentration above the national maximum permissible concentration (0.39 mg NH4-N/l), but this level is quite high in comparison with e.g. the recommended levels in the EU Directive 78/659/EEC (cyprinid fish: 0.16 mg NH4-N/l; salmonid fish: 0.03 NH4-N/l). With a threshold of 0.16 mg NH4-N/l, average concentration was above the threshold at 72% of the sites in 2017.
Indicator specification
Indicator definition
The level of oxygen concentration in water bodies, expressed as biochemical oxygen demand (BOD) - which is the amount of dissolved oxygen required for the aerobic decomposition of organic matter present in water - and the level of concentrations of ammonium (NH4/N-NH4) in rivers.
Units
The annual average BOD after five days of incubation (BOD5) at 20 degrees Celsius is expressed in mg of O2/litre; the ammonium concentration is expressed in mg of N/litre.
Rationale
Justification for indicator selection
Large quantities of organic matter (microbes and decaying organic waste) can result in reduced chemical and biological quality of river water, impaired biodiversity of aquatic communities, and microbiological contamination that can affect the quality of drinking and bathing water. Sources of organic matter are discharges from wastewater, industrial effluents and agricultural runoff. Organic pollution leads to higher rates of metabolic processes that demand oxygen. This could result in the development of water zones without oxygen (anaerobic conditions). The transformation of nitrogen to reduced forms under anaerobic conditions, in turn, leads to increased concentrations of ammonium, which is toxic to aquatic life above certain concentrations, depending on water temperature, salinity and pH.
Scientific references
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Council Directive 91/271/EEC of 21 May 1991 concerning urban wastewater treatment
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Directive 2000/60/EC of the European Parliament and the Council of 23 October 2000 establishing a framework for Community action in the field of water policy (Water Framework Directive) http://ec.europa.eu/environment/water/waterframework/index_en.html;
Policy context and targets
Context description
National policy context
The strategic goal of preserving the country's water potential is to improve the efficiency of use and improve the quality of the water resources, balanced with the needs of society and possible climate change. This indicator is not directly related to any specific target indicator, enshrined in strategic documents. However, general regulations on the environmental quality of surface waters are contained in the following regulatory legal acts of the Republic:
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Water strategy of the Republic of Belarus for the period up to 2020.
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The Law of the Republic of Belarus of November 26, 1992 No. 1982-XII “On Environmental Protection”.
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The Water Code of the Republic of Belarus of April 30, 2014 No. 149-Z.
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Order of the Ministry of Natural Resources and Environmental Protection of the Republic of Belarus “On approval of environmental indicators of the state of the environment in the Republic of Belarus” of 12/12/2009 No. 377-ОD.
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Resolution of the Ministry of Environment dated March 30, 2015 No. 13 “On the establishment of standards for the quality of water of surface water bodies”.
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TCP 17.13-08-2013 Environmental protection and environmental management. Analytical control and monitoring. Rules for determining the chemical (hydrochemical) status of river ecosystems;
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TCP 17.13-09-2013 Environmental protection and environmental management. Analytical control and monitoring. Rules for determining the chemical (hydrochemical) status of lake ecosystems;
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TCP 17.13-10-2013 Environmental protection and environmental management. Analytical control and monitoring. Rules for determining the ecological (hydrobiological) status of river ecosystems;
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TCP 17.13-11-2013 Environmental protection and environmental management. Analytical control Requires “on establishing the norms for assuring water quality of each Water Basin Management District, depending upon local peculiarities” and monitoring. Rules for determining the ecological (hydrobiological) status of lake ecosystems.
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Online link to the policy documents :
International policy context
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The Convention on the Protection and Use of Transboundary Watercourses and International Lakes (Water Convention) aims to ensure the sustainable use of transboundary water resources by facilitating cooperation. The Water Convention strengthens transboundary water cooperation and measures for the ecologically-sound management and protection of transboundary surface waters and groundwater.
Targets
National targets
In Belarus, the quality standard for BOD is 3.00 mg O2/l for surface water bodies used for breeding and feeding by wintering or migrating salmon and sturgeon species, and 6.00 mg O2/l for other surface water bodies.
The maximum permissible concentration for ammonium concentration is 0.39 mg NH4-N/l.
International targets
The UN Sustainable Development Goal 6 target 6.3 aims to achieve, by 2030, improve water quality by reducing pollution, eliminating dumping and minimizing release of hazardous chemicals and materials, halving the proportion of untreated wastewater and substantially increasing recycling and safe reuse globally.
Related policy documents
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Water strategy of the Republic of Belarus for the period up to 2020.
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The Law of the Republic of Belarus of November 26, 1992 No. 1982-XII “On Environmental Protection”.
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The Water Code of the Republic of Belarus of April 30, 2014 No. 149-Z.
Methodology
Methodology for indicator calculation
Monitoring data from 86 rivers is included. Each river may have one to several monitoring sites. The monitoring frequency is normally monthly.
The sampling of surface waters is carried out in accordance with the requirements of STB 17.13.05-10-2009 / ISO 5667-6: 2005. Chemical analyses are done according to STB 17.13.05-23-2011 / ISO 5815-2: 2003 (BOD5) and STB 17.13.05-09-2009 / ISO 7150-1: 1984 (ammonium).
The average annual concentration was estimated on the basis of the results for individual samples for each monitoring site. For the time series analysis the results from individual monitoring sites were aggregated to river level. Time series aggregated to the whole country or different river basins (Western Dvina, Neman, Western Bug, Dnieper and Pripyat) were then calculated as the average of the individual annual time series for each river for the different determinants.
For the present state analysis, annual average values per monitoring site for 2017 were used. Each monitoring site was assigned to different classes based on the annual average.
Methodology for gap filling
No gap filling has been performed
Methodology references
The regulation on the procedure for conducting monitoring of surface waters and using its data in the National Environmental Monitoring System in the Republic of Belarus // Resolution of the Council of Ministers of the Republic of Belarus of April 28, 2004 No. 482 (www.analitcentre.by ).
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STB 17.13.05-10-2009 / ISO 5667-6: 2005 Environmental protection and environmental management. Analytical control and monitoring. Water quality. Sample selection. Part 6. Guide to sampling from rivers and other watercourses.
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STB 17.13.05-23-2011 / ISO 5815-2: 2003 Environmental protection and environmental management. Analytical control and monitoring. Water quality. Determination of biochemical oxygen consumption after n days (BODn). Part 2. Method without diluting samples.
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STB 17.13.05-09-2009 / ISO 7150-1: 1984 Environmental protection and environmental management. Analytical control and monitoring. Water quality Determination of ammonium nitrogen. H 1. Manual spectrometric method.
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EEA, 2005. EEA core set of indicators guide. EEA Technical report No 1/2005, ISBN 92-9167-757-4, Luxembourg.
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UNECE, 2018. Guidelines for the Application of Environmental Indicators, Description of C10. Biochemical oxygen demand (BOD) and concentration of ammonium in rivers.
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UNECE, 2018. Guidelines for the Application of Environmental Indicators, Glossary of terms – C10. Biochemical oxygen demand (BOD) and concentration of ammonium in rivers.
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UNSD and UNEP, 2013. Questionnaire 2013 on Environment Statistics. United Nations Statistics Division and United Nations Environment Programme, Questionnaire 2013 on Environment Statistics, Section Water.
Uncertainties
Methodology uncertainty
No methodological uncertainty has been specified.
Data sets uncertainty
No uncertainty has been specified.
Rationale uncertainty
Biochemical oxygen demand and total ammonium are well suited for illustrating water pollution with oxygen consumption. However, using annual average values may not fully illustrate the severity of low oxygen conditions.
Data sources
Data was provided from National Environmental Monitoring System by the Ministry of Natural Resources and Environmental Protection of the Republic of Belarus under the ENI SEIS II East project activities
C10 – Biochemical oxygen demand and concentration of ammonium in rivers provided by National Statistical Committee of the Republic of Belarus