The indicator provides a measure of the state of freshwater (rivers, lakes and groundwater) in terms of nutrient concentration.

In Armenia, the main sources of nutrients include urban wastewater, agricultural runoff, rainwater, and snowmelt. Inputs of nutrients from both point and fugitive sources can lead to qualitative changes in freshwater, contribute to eutrophication, and adversely affect aquatic ecosystems. Nitrate pollution is primarily associated with agricultural activities, while phosphate pollution is linked to both agricultural runoff and wastewater discharges resulting from the use of detergents.

Between 2010 and 2024, average phosphate concentrations in Armenian rivers increased by 22% (from 0.09 to 0.11 mg P/l). The Hrazdan River, one of the longest and most polluted rivers in Armenia and the river closest to Yerevan (population of approximately 1 million), recorded particularly high phosphate concentrations at 55th observation point. Over the period 2010–2024, average phosphate concentrations at observation points below settlements, including 55th observation point, were 1.1–1.4 times higher than those calculated for the same period excluding 55th observation point.

Over the same period, average nitrate concentrations in Armenian rivers decreased by 39% (from 7.15 to 4.33 mg/l), which may be attributed to a reduction in the use of nitrogen fertilizers.

2024 Annual Average Concentration Classes by RA WBMAs 

Phosphate	Nitrate

Note: Water quality classes determined by phosphate (left) and nitrate (right) based on the average annual concentrations of river observation points in 2024. The maps were provided by the “Hydrometeorology and Monitoring Center” SNCO of the Ministry of Environment of the RA. The national assessment system has been applied. For information on the relevant national norms, see the indicator description in the “National Target” section. The assessment system is the same as that used for the EEA indicator WAT 002-Oxygen Depleting Substances in European Rivers.

The proportion of water quality classes at the observation points in 2024, determined by phosphates, is as follows:

• Northern WBMA: 67% "high", 17% "good", 17% "moderate"
• Akhuryan WBMA: 20% "good", 20% " moderate ", 40% "poor", 20% "bad"
• Hrazdan WBMA: 12% "high", 38% "good", 25% "moderate", 12% "poor", 12% "bad"
• Sevan WBMA: 50% "high", 25% "good", 25% " moderate"
• Ararat WBMA: 100% "high"
• Southern WBMA: 58% "high", 25% "moderate", 17% "poor"

The proportion of water quality classes at the observation points in 2024, determined by nitrates, is as follows:

• Northern WBMA: 33% " moderate", 33% "poor", 33% "bad"
• Akhuryan WBMA: 60% " moderate", 40% "poor"
• Hrazdan WBMA: 12% "high", 50% "moderate", 25% "poor", 12% "bad"
• Sevan WBMA: 42% "high", 25% "good", 8% " moderate", 25% "poor"
• Ararat WBMA: 100% "good"
• Southern WBMA: 17% "high", 42% "good", 33% " moderate", 8% "poor"

Indicator definition

C11 Indicator - The concentrations of nutrients in rivers, the indicators of which are phosphates and nitrates.

Units

Phosphates: mg P/l,
Nitrates: mg/l.

Rationale

Justification for indicator selection

High concentrations of nutrients can adversely affect river water quality, leading to increased pollution, disruption of aquatic ecosystem balance, and a decline in biodiversity, thereby negatively impacting overall water quality.

References

• Urban Waste Water Directive - Environment
• Directive 2000/60/EC of the European Parliament and of the Council establishing a framework for Community action in the field of water policy
• UNECE, 2018. Guidelines for the Application of Environmental Indicators, Description of C11. Nutrients in freshwater.
• UNECE, 2018. Guidelines for the Application of Environmental Indicators, Glossary of terms – Description of C11. Nutrients in freshwater.

Context description

National policy context

• Water Code of the Republic of Armenia (adopted on June 4, 2002)
  The Water Code regulates water relations concerning the use, protection, and development of water resources to ensure a guaranteed, adequate, and safe water supply for the population, protect the environment, and promote the rational development of the country’s water fund.
• N75-Ն RA Government Resolution (adopted on 27 January, 2011)                                                                                      On establishing standards for ensuring water quality in each water basin management area, depending on the specifics of the location.” This resolution sets water quality standards for each water basin management area, taking into account the specific characteristics of the location.

International policy context

The UNECE–WHO/European Protocol on Water and Health aims to protect human health and well-being through sustainable water management and by preventing and controlling water-related diseases. It provides a framework for the translation human rights to water and sanitation into practice, as well as for the implementation of SDG 6. Although the Protocol was signed in 1999, its ratification is still ongoing and has not yet been finalized.

Targets

National targets
Standards according to N75-Ն RA Government Resolution

International targets

The UN Sustainable Development Goal 6, Target 6.3, aims to achieve improved water quality by 2030 through reducing pollution, eliminating waste, and minimizing the release of hazardous chemicals and materials. It also seeks to halve the proportion of untreated wastewater and substantially increase the recycling and safe reuse of water globally.

Methodology for indicator calculation

The monitoring programme is designed to take into account the spatial and seasonal dynamics of the indicators. Monitoring sites are located both above and below settlements, which provides information on background concentrations as well as on settlement-related impacts. The number of river observation points is 45 (21 above and 24 below settlements), representing 22 rivers. The data are provided by the “Hydrometeorology and Monitoring Center” SNCO of the Ministry of Environment of the RA. For each observation point, the annual average concentrations of BOD₅ and ammonium are calculated based on the arithmetic mean of the monitoring data obtained during the year. Separate averages are calculated for river observation points above and below settlements

Gap-filling methodology

For the analysis of time series and their trends, only complete series are used (i.e., there are no missing values in the site data set). This ensures the consistency of the averaged data sets. Thus, there was no need to apply a gap-filling methodology.

Methodology references

• ISO 6878:2004- Water quality — Determination of phosphorus — Ammonium molybdate spectrometric method.
• ISO 7890-3:1988— Determination of nitrate — Part 3: Spectrometric method using sulfosalicylic acid.
• EEA, 2005. EEA core set of indicators guide.
• UNECE, 2018. Guidelines for the Application of Environmental Indicators, Glossary of terms – C11. Nutrients in freshwater.
• UNSD/UNEP Questionnaire on Environment Statistics.

Methodology uncertainty
No methodological uncertainty has been identified.

Data sets uncertainty
No uncertainty has been identified.

Rationale uncertainty
Biochemical oxygen demand and ammonium are indicators that characterize water pollution related to oxygen consumption. However, their annual average values do not always fully represent the actual situation, as they do not capture seasonal fluctuations.

• ArmStatBank
  River water quality indicators by observation points and years.
  Data on BOD₅ and ammonium concentrations in surface water are available and stored in the national database of the “Hydrometeorology and Monitoring Center” SNCO of the Ministry of Environment of the RA.
• Report on the State of Environment
  Water quality assessments (according to national water quality standards) are published by the “Hydrometeorology and Monitoring Center” SNCO of the Ministry of Environment of the RA.