C10 – Biological oxygen demand and concentration of ammonium in rivers of Ukraine
Is organic matter and ammonium pollution in rivers in Ukraine decreasing?
Figure 1 – Change in mean ammonium concentration in rivers in Ukraine (2000-2017)
Data sources: Data were provided by the Ministry of Ecology and Natural Resources of Ukraine under the ENI SEIS II East project activities.
Note: The data series is calculated as the average of the annual mean concentrations of ammonium (mg N/l) for seven rivers in Ukraine for the period 1990-2017. The total number of river sites included in the analysis for this period, with full data sets from 2000 onwards, is 90.
Figure 2 – Change in mean BOD5 in rivers in Ukraine (2000-2017)
Data sources: Data were provided by the Ministry of Ecology and Natural Resources of Ukraine under the ENI SEIS II East project activities.
Note: The data series is calculated as the average of the annual mean concentrations of BOD5 (mg O2/l) for seven rivers in Ukraine for the period 1990-2017. The total number of river sites included into the analysis for this period, with full data sets from 2000 onwards, is 89.
BOD and ammonium are key indicators of organic pollution in water. The 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 effluent and agricultural run-off. Severe organic pollution may lead to rapid de-oxygenation of river water, high concentrations of ammonia and the disappearance of fish and aquatic invertebrates. Some of the year-to-year variation can be explained by the variations in precipitation and run-off.
The average BOD in Ukrainian rivers was lowest in 2010, at 2.85 mg O2/l, after which it started to increase and reached 3.32 mg O2/l in 2016. In the last 18 years, the lowest average ammonium concentration, 0.318 mg N/l, was in 2009, and the highest, 0.65 mg N/l, was in 2017.
The concentration of ammonium in the period 2000 – 2017 oscillated for almost 0.4 mg N/l. The lowest average annual concentration was 0.38 mg N/l in 2009. In the last three years, the annual average ammonium concentrations are increasing. In 2017, it reached the highest value, 0.65 mg N/l.
What is the trend of organic matter and ammonium pollution of rivers in Ukraine?
Figure 3 – Changes in ammonium concentrations in rivers in Ukraine (2000-2017)
Data sources: Data were provided by the Ministry of Ecology and Natural Resources of Ukraine under the ENI SEIS II East project activities.
Note: The data series are calculated as the averages of the annual mean concentrations of ammonium (mg NH4-N/l) for seven rivers in Ukraine for the period 2000-2017. The total number of river sites included in the analysis, with full data sets from 2000 onwards, is 90 (Tisa 5, Siverski Donets 16, Prut 5, Pivdenni Bug 19, Dnister 15, Dnipro 29, and Desna 1).
Figure 4 – Changes BOD5 in rivers in Ukraine (2000-2017)
Data sources: Data were provided by the Ministry of Ecology and Natural Resources of Ukraine under the ENI SEIS II East project activities.
Note: The data series are calculated as the averages of the annual mean concentrations of BOD5 (mg O2/l) for seven rivers in Ukraine for the period 1990-2017. The total number of river sites included in the analysis, with full data sets from 2000 onwards, is 89 (Tisa 5, Siverski Donets 16, Prut 5, Pivdenni Bug 19, Dnister 16, Dnipro 27 and Desna 1).
The river most polluted with organic matter and ammonium is Pivdenni Bug. Although the time series data from the sampling sites on Pivdenni Bug are very variable, they show that pollution has been increasing in recent years.
The rivers with the least organic matter pollution are the Desna and Prut rivers. The Tisa river has the least ammonium pollution of all the rivers in Ukraine.
What is the current state of organic matter and ammonium pollution of the main rivers in Ukraine?
Figure 5 – Current concentration of ammonium in rivers in Ukraine (2017)
Data sources: Data were provided by the Ministry of Ecology and Natural Resources of Ukraine under the ENI SEIS II East project activities.
Note: The current concentration is calculated as the average of the mean concentrations of ammonium (mg N/l) in Ukraine for the year 2017. The total number of river sites included in the analysis is 131. The number of monitoring sites per river is given in parenthesis.
Five per cent of the measured sites on rivers in Ukraine have low ammonium pollution. Two thirds of sites (65 %) an increased level of pollution (between 0.1 and 0.4 mg N/l). Almost one third (30 %) of sites are highly polluted with ammonium.
The rivers most polluted with ammonium are Sievercki Donets and Desna. All their sites have ammonium concentrations of over 0.2 mg N/l. There is also high ammonium pollution at sites on the Dnipro river. Here, 83 % (45) of sites have high levels of pollution (> 0.2 mg N/l). The remainder (nine sites) are moderately polluted with ammonium (0.1-0. 2 mg N/l). All sites on the Prut river are at least moderately polluted with ammonium.
The ammonium concentrations at sites on the Dnester river show the highest diversity. Two sites have low concentrations, five moderate, six high and six very high concentrations. The sites with low and high ammonium pollution alternate along the river and show a decreasing trend downstream.
Figure 6 – Current concentration of BOD5 in rivers of Ukraine (2017)
Data sources: Data were provided by the Ministry of Ecology and Natural Resources of Ukraine under the ENI SEIS II East project activities.
Note: The current concentration is calculated as the average of mean concentrations of BOD5 (mg O2/l) in Ukraine for the year 2017. The total number of river sites included in the analysis is 131. The number of monitoring sites per river is given in parenthesis.
Almost one fifth of the measured sites on rivers in Ukraine have low organic matter pollution. Two thirds of sites (67 %) have a medium level (between 2.0 and 4.0 mg O2/l) or an increased level of organic matter pollution (between 4.0 and 6.0 mg O2/l). 16 % of the sites are highly polluted with organic matter.
Almost three quarters of the sites (14) on Pivdenni Bug have very high concentration of BOD5 (> 0.4 mg O2/l). The Sievercki Donets and Tisa rivers also have high levels of organic matter pollution. On the Sivercki Donets 88 % of sites (14) have concentrations that are higher than 3.0 mg O2/l. On the Tisa and Prut rivers most of the sites are moderately polluted. The river least polluted with organic matter is the Desna.
The rivers most polluted with organic matter and ammonium are the Sievercki Donets and Pievdenni Bug. The Desna river has high levels of ammonium pollution but low organic matter pollution. The Dnister and Dnipro rivers are moderately to heavily polluted with both ammonium and organic matter. As shown in Figures 3 and 4, both concentrations are actually increasing.
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 5 days of incubation (BOD5) at 20 °C is expressed in mg of O2/l; the ammonium concentration is expressed in mg of N/l.
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 waste water treatment plants, industrial effluents and agricultural run-off. Organic pollution leads to higher rates of metabolic processes that demand oxygen.
Scientific references
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Council Directive 91/271/EEC of 21 May 1991 concerning urban waste-water 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;
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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, United Nations Economic Commission for Europe.
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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, United Nations Economic Commission for Europe.
Policy context and targets
Context description
National policy context
Law of Ukraine ‘On amendments to certain legislative acts of Ukraine on implementation of integrated approaches to basin water management’, Verkhovna Rada of Ukraine, adopted on 4 October 2016.
Resolution No 758 ‘On approval of the procedure of the state monitoring of waters, the Cabinet of Ministers of Ukraine, adopted 19 September 2018.
International policy context
There are several EU directives that aim to improve water quality and reduce impacts, the major one being the Water Framework Directive, which requires the achievement of good ecological status or good ecological potential of surface water bodies. In accordance with the EU-Georgia Association Agreement, the country has an obligation to comply with the requirements of these Directives.
Targets
National targets
To reduce organic pollution in Ukrainian rivers and to achieve good ecological status.
In 2011 the Ministry of Ecology and Natural Resources approved ‘National targets of Ukraine to the Protocol on Water and Health’; meeting these targets indirectly reduces pressures on water quality. Ammonium and BOD5 concentrations in water are expected to be reduced by meeting the following targets:
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Target 7: improve the access to centralised sewerage systems. Indicators: percentages of urban and rural populations with access to improved sanitation. Targets in 2015 and 2020: in cities and towns 80 % (2015) and 100 % (2020); in rural areas 20 % in 2015 and 50 % in 2020.
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Target 10: reduce the amount of waste water discharged (including from mining and quarries, and drainage water) with non-existent or inadequate treatment. Targets for discharges without treatment: 3 % in 2015 and 1.5 % in 2020; targets for discharges with inadequate treatment: 15 % in 2015 and 10 % in 2020.
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Target 12: adoption of river basin management plans for the Danube, Tisa and Southern Bug rivers in 2015 and for the Dnipro, Dniester and Seversky Donets rivers in 2020.
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
Resolution No 758 ‘On approval of the procedure of the state monitoring of waters, the Cabinet of Ministers of Ukraine, adopted 19 September 2018.
Methodology
Methodology for indicator calculation
Annual mean concentrations are used as a basis in the present concentration and trend analyses. An outlier test based on z-scores is applied to the averages of the annual mean concentrations of BOD5 and ammonium; data failing the tests are excluded from further analysis. For time series and trend analyses, only series that are complete after interpolation/extrapolation (i.e. no missing values in the site data series) are used. This is to ensure that the aggregated data series are consistent, i.e. including the same sites throughout the time series. In this way assessments are based on actual changes in concentration, and not on changes in the number of sites. The selected time series are aggregated by country and by river catchments, averaging across monitoring sites for each year, with full time series for the period 2000-2017.
The present state of pollution is represented by the average concentrations in the last year. In this case all monitoring sites are used, which is a far higher number than those that have complete time series after interpolation/extrapolation.
The sites are assigned to different concentration classes and summarised (count of sites per concentration class). The classes’ defining values are based on the range of concentrations found in the database and only give an indication of the relative distribution of the values of BOD5 and ammonium.
Methodology for gap-filling
Gaps of up to 3 years, both at the ends and in the middle of the data series, are extrapolated or interpolated. At the beginning and the end of the data series up to 3 years of missing values are replaced by the first or the last value of the original data series, respectively. In the middle of the data series, missing values are replaced by the values next to them, except for gaps of 1 year and for the middle year in gaps of 3 years, in which missing values are replaced by the average of the two neighbouring values.
Methodology references
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EEA, 2005, EEA core set of indicators guide, EEA Technical Report No 1/2005, Office for Official Publications of the European Communities, Luxembourg.
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UNSD and UNEP, 2013, ‘Questionnaire 2013 on environment statistics, section: water’, United Nations Statistics Division and United Nations Environment Programme.
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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.
Uncertainties
Methodology uncertainty
No methodological uncertainty has been specified.
Data sets uncertainty
No uncertainty has been specified.
Rationale uncertainty
No uncertainty has been specified.
Data sources
Data were provided by the Ministry of Ecology and Natural Resources of Ukraine under the ENI SEIS II East project activities.
Foundation "Open Society". Monitoring and environmental assessment of water resources of Ukraine’. http://openenvironment.org.ua/water/ .