C10 - BOD and concentration of ammonium in rivers of the Republic of Armenia
Is organic matter and ammonium pollution in rivers in the Republic of Armenia decreasing?
Figure 1 - Rivers – Annual mean biological oxygen demand - BOD (2008-2017)
Data sources:
Data was provided by the Ministry of Environment of the Republic of Armenia under the ENI SEIS II East project activities
(C10, C11) Water quality indicator, by observation points and years provided by ArmStatBank
Note: The data series are calculated as the average of annual mean BOD (mg O2/l) for river sites in Armenia for the period 2008-2017. The number of river sites is 45 (21 sites above settlements and 24 sites below), representing 22 rivers. The right hand plots show the average time series without the site 55.
Figure 2 - Rivers - mean ammonium concentration (2008-2017)
Data sources:
Data was provided by the Ministry of Environment of the Republic of Armenia under the ENI SEIS II East project activities
(C10, C11) Water quality indicator, by observation points and years provided by ArmStatBank
Note: The data series are calculated as the average of annual mean ammonium concentration (NH4-N/l) for river sites in Armenia for the period 2008-2017. The number of river sites is 45 (21 sites above settlements and 24 sites below), representing 22 rivers. The right hand plots show the average time series without the site 55.
Biochemical oxygen demand (BOD) and ammonium are key indicators of organic pollution in water. BOD shows how much dissolved oxygen is consumed in the decomposition of organic matter present in water. Concentrations of these parameters normally increase as a result of organic pollution caused by discharges from wastewater treatment plants, industrial effluents and agricultural runoff. Severe organic pollution may lead to rapid de-oxygenation of river water, high concentration of ammonium and disappearance of fish and aquatic invertebrates. The main source of organic pollution in Armenia is non-treated or not sufficiently treated wastewater, which, due to the lack of treatment plants, is emitted to the river. There are only six treatment plants in Armenia, with mechanical treatment only.
The BOD and ammonium concentration have increased below settlements in the period 2011 to 2017, due to discharge of untreated domestic wastewater from settlements and agriculture run-off. Over the period 2008 to 2017 average BOD increased by 25% and average ammonium concentration by 74% for sites below settlements. Average BOD and ammonium concentration for river sites above settlements have remained more or less stable. This indicates that there are limited changes in activities causing emissions in the less populated areas. Across all sites, the increase from 2008 to 2017 was thus slightly less than for the sites below settlements (18% and 72% for BOD and ammonium concentration, respectively).
River Hrazdan is one of the longest and most polluted rivers in Armenia. The effect of the influence of untreated wastewater is obvious especially at the monitoring site 55, which is the nearest and most impacted site after Yerevan city, the capital of Armenia, with about 1 million inhabitants. This has a major impact on the average time series, especially for ammonium. In 2017, the average ammonium concentration at sites below settlements was two times higher when including monitoring site 55 and the difference between the averages with and without this site has increased over time. For BOD, the difference is less, but also here it has increased over time, meaning that the BOD has increased more at site 55 than at other sites. At the beginning of the time series the average of sites below settlements was around 5% lower when excluding site 55, while it was around 20% lower at the end of the time series. Excluding site 55 the increase from 2008 to 2017 across all sites was 7% for BOD and 40% for ammonium concentration.
What is the current state of organic matter and ammonium pollution of rivers in the Republic of Armenia?
Figure 3 - Rivers – BOD and Ammonium (2017), using the national classification system
Data sources:
Data was provided by the Ministry of Environment of the Republic of Armenia under the ENI SEIS II East project activities
(C10, C11) Water quality indicator, by observation points and years provided by ArmStatBank
Note: Distribution of river monitoring sites to BOD (left) and ammonium (right) water quality classes in the different river basins (Akhuryan, Ararat, Hrazdan, Northern, Sevan, Southern) of the Republic of Armenia, based on annual average concentrations for 2017. The number of monitoring sites per river basin is given in parenthesis. The national class system is used. See the “National target” section of the indicator specification for detailed information on the applied national classes.
Figure 4 - Rivers – BOD (2017)
Data sources:
The map was provided by the Ministry of Environment of the Republic of Armenia under the ENI SEIS II East project activities
Note: Distribution of river monitoring sites to BOD classes in the different river basins (Akhuryan, Ararat, Hrazdan, Northern, Sevan, Southern) of the Republic of Armenia, based on annual average concentrations for 2017.
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
Figure 5 - Rivers – Ammonium (2017)
Data sources:
The map was provided by the Ministry of Environment of the Republic of Armenia under the ENI SEIS II East project activities
Note: Distribution of river monitoring sites to ammonium concentration classes in the different river basins (Akhuryan, Ararat, Hrazdan, Northern, Sevan, Southern) of the Republic of Armenia, based on annual average concentrations for 2017.
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
The average BOD for sites below settlements was 46% higher than the average for sites above settlements in 2017, reflecting the discharge from untreated wastewater, in particular. The difference was far bigger for ammonium, where the average for sites below settlements was 17 times higher than the average for sites above settlements in 2017 (9 times higher if excluding site 55).
In 2017, the monitoring site in River Hrazdan below Yerevan City (monitoring site 55) was classified as bad quality for BOD according to the national water quality norm. The remaining sites of the Hrazdan river basin, were classified to be in good or high quality. The sites in the Akhuryan river basin were classified as having good or high quality with respect to BOD, with the exception of one site classified as moderate quality. In the Southern and Northern river basins, water quality was classified as good or high with respect to BOD. In the Sevan river basin, all sites were classified as high quality with respect to BOD. The reason for the low BOD in rivers in the Sevan river basin are that the water pollution is mainly diffuse, which does not have a big impact on these rivers. However, it does have an impact on Lake Sevan, which is affected by urban wastewater and agriculture runoff discharged directly into the lake.
Based on average concentrations of ammonium in 2017 the river sites below settlements mainly belong to the poor or bad quality classes and sites above settlements to the good quality class. Ammonium concentration was classified as bad quality for sites in the Hrazdan (38%), Southern and Northern (both 17%) river basins. The Akhuryan river basin had the highest proportion of sites in less than good quality (80%).The best quality was found in the Sevan river basin with 92% of the sites in high or good quality. As for BOD, the rivers in the Sevan river basin are mainly subject to diffuse sources of water pollution, which do not have a big impact on these rivers.
Overall the highest BOD and ammonium concentration in 2017 is observed at the river site below Yerevan City in River Hrazdan (monitoring site 55). The Hrazdan river basin, which is the most populated river basin in Armenia, has the highest proportion of sites in bad quality, and the situation is worst for ammonium concentration. The Akhuryan river basin has the highest proportion of sites in less than good quality, and again the proportion is far higher for ammonium. The second most populated city (Gyumri) is located in this river basin. The wastewaters of both cities discharge directly into the rivers, due to lack of wastewater treatment plants.
The good/moderate thresholds in the national norms are higher than the recommended levels in the EU Directive 78/659/EEC, with the exception of the BOD threshold for cyprinid fish (cyprinid fish: 0.16 mg NH4-N/l, 6 mg O2/l; salmonid fish: 0.03 NH4-N/l, mg 3 mg O2/l). All river basins (except Araratyan) have river sites where the ammonium concentration in 2017 exceeds the recommended concentration for cyprinid fish. Most of the elevated concentrations were found below settlements, but some were also above settlements. Elevated concentrations may sometimes be found also above settlements, because the headwaters are not protected by legislation. Work is implemented to try to fill a gap in the legislation to protect these areas, starting with Akhuryan river basin. The recommended concentration for salmonid fish was always exceeded for ammonium and at 42% of the sites for BOD.
To reduce pollution of surface waters (especially in the Sevan river basin) there is new legislation that requires local treatment of wastewater from recreation areas before it is discharged to rivers or directly in the lake.
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;
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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.
Policy context and targets
Context description
National policy context
This Code regulates water relations in the field of use, protection and development of water resources for guaranteed, adequate and safe supply of water for the population, protection of the environment and promotion of the rational development of the water fund of the country.
Requires “on establishing the norms for assuring water quality of each Water Basin Management District, depending upon local peculiarities”
International policy context
The UNECE-WHO/Europe Protocol on Water and Health aims to protect human health by better water management and by reducing water-related diseases. The Protocol provides a framework to translate into practice the human rights to water and sanitation and to implement SDG 6. Armenia has signed the Water and Health Protocol in 1999, however, ratification is under the process and not finalized yet.
Targets
National targets
The norms for some parameters according to Government Decision №75-N:
|
Parameter |
Water Classes |
||||
|
I (high) |
II (good) |
III (moderate) |
IV (poor) |
V (bad) |
|
|
Ammonium (mg NH4-N/l) |
<0.2 |
0.2-0.4 |
0.4-1.2 |
1.2-2.4 |
>2.4 |
|
BOD (mg O2/l) |
<3.0 |
3.0-5.0 |
5.0-9.0 |
9.0-18 |
>18 |
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
Methodology
Methodology for indicator calculation
The monitoring programme for BOD and ammonium concentrations in rivers is structured to take into account the spatial and temporal dynamics of the indicators. The monitoring sites are located both before and after settlements, which provides information both on background concentrations and the influence of the settlements. The number of rivers sites is 45 (21 sites above settlements and 23 below), representing 22 rivers. The monitoring frequency is 7-12 per year, covering all hydrological phases.
The chemical analyses are carried out at the Laboratory of Environmental Monitoring and Information Center of the Ministry of Environment of the Republic of Armenia.
Annual time series for each site are calculated by averaging the values for individual samples per year. Aggregated time series are calculated as the average of the individual annual time series. For rivers separate aggregations are made for river sites above and below settlements.
Methodology for gap filling
For time series and trend analyses, only series that are complete (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 changes in the number of sites. Hence, no gap filling has been applied.
Methodology references
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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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ISO 7150-1:1984 Water quality — Determination of ammonium — Part 1: Manual spectrometric method. The procedure is applicable to the analysis of potable water, and most raw and waste waters. Application to excessively coloured or saline waters shall be preceded by distillation.
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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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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
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ArmStat - Annual mean BOD and ammonium concentration values for most monitoring sites are published at ARMSTAT
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Environmental Monitoring and Information Center SNCO - Data on BOD and ammonium concentration in surface waters are available for several decades (since 1977) and are stored in the national database: Water Base - Environmental Monitoring and Information Center SNCO, Ministry of Nature Protection Republic of Armenia
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Water Quality report 2018. The classification of the river monitoring sites based on BOD and ammonium concentration (according to national water quality norms) are published in monthly and annual surface water quality reports by the Environmental Monitoring and Information Center SNCO, Ministry of Nature Protection Republic of Armenia.