Types of Monitoring

Types of Monitoring

Water status monitoring is divided into three main components in accordance with the objectives: surveillance monitoring, operational monitoring, and research monitoring.

1. Surveillance Monitoring, aimed at

• assessing long-term changes in natural conditions
• evaluating long-term changes caused by intensive human activities
• planning future monitoring activities
• supplementing and validating the assessment process of human activities’ impact on the condition of water.

2. Operational Monitoring, aimed at

• the condition of surface water and groundwater bodies identified as being at risk of water protection objectives
• determining the condition of surface waters receiving discharges of priority substances, and the condition of groundwater to detect significant and continuous upward trends in pollutant concentrations due to human activities
• identifying any changes in the status of such water bodies resulting from the implementation of the Measures Programme.

3. Research Monitoring is carried out when

• the causes of threshold exceedances for water status indicators within the DPSIR1 cycle are unknown
• surveillance monitoring indicates that a specific surface water body is unlikely to achieve water protection objectives, but operational monitoring has not yet been established, in order to identify the reasons for failing to meet these objectives
• it is necessary to determine the extent and impact of sudden pollution incidents, and
• data is needed to develop a programme of measures aimed at achieving water protection objectives and to define special measures for mitigating the consequences of sudden pollution incidents.

Monitoring of the Watch List Substances

Monitoring also includes the tracking of substances on the EU Watch List, which must be monitored across the European Union within the framework of water policy. It is conducted at selected stations during a minimum period of one year.

Monitoring Station Network

The network of monitoring stations for assessing the condition of surface waters is designed to:

• provide a comprehensive overview of the ecological and chemical condition of surface waters within the river basin district.
• It facilitates the classification of surface water bodies in terms of their chemical status, ecological status, and ecological potential, in line with regulatory definitions set out in the relevant regulation.

Quality Elements for Assessing the Ecological Status / Potential of Water

The assessment of ecological status/potential is based on several key quality elements, grouped into four main categories: biological elements, basic physico-chemical elements, specific pollutants, and hydromorphological elements.

Based on the definitions outlined in the Water Framework Directive, five biological elements can be distinguished in rivers and lakes: phytoplankton, phytobenthos, macrophytes, macrozoobenthos and fish.

The biological quality elements for transitional waters include phytoplankton, macroalgae, seagrasses, macrozoobenthos, and fish. In coastal waters, the biological quality elements encompass pytoplankton, macroalgae, seagrasses, and macrozoobenthos.

The basic physico-chemical and chemical quality elements in surface freshwater bodies are temperature, salinity, pH, oxygen regime, nutrient concentrations, and specific pollutants (arsenic, copper, zinc, chromium and their compounds, fluorides, and organically bound halogens). In transitional and coastal waters, these elements include temperature, oxygen regime conditions, transparency, nutrient concentrations, and specific pollutants.

The hydromorphological quality elements for rivers include elements of the hydrological regime, river continuity, and morphological conditions, while for lakes, they include the hydrological regime and morphological conditions. For transitional and coastal waters, the hydromorphological elements encompass the tide regime and morphological conditions.

In addition to the indicators used for assessing ecological status within surveillance and operational monitoring, additional physico-chemical indicators, ions, and pollutantsbare also monitored, as they are particularly relevant for tracking the effects of air pollution on aquatic ecosystems.

Elements of Chemical Status

The elements of chemical status include priority and hazardous substances, which are assessed based on environmental quality standards defined for each category of substances. A good chemical status is achieved when the observed indicators do not exceed the threshold values, expressed as:

• Annual average concentration.
• Maximum annual concentration.
• Quality standards for biota for specific categories of substances.

Chemical pollution of surface waters poses a threat to the aquatic environment due to effects such as acute and chronic toxicity to aquatic organisms, accumulation in ecosystems, and the loss of habitats and biodiversity. Moreover, it also represents a risk to human health. The Watch List includes substances or groups of substances that are not systematically monitored nor subject to discharge control under current regulations, meaning that there is limited data on their presence and potential adverse effects in the aquatic environment.

Water Status Assessment

• Surface Waters: The assessment of surface waters is based on their ecological and chemical condition, with the lower rating being the determining factor. Surface waters are considered to be in good condition if they exhibit either very good or good ecological status and good chemical status.
• Groundwater: The assessment is based on the quantitative and chemical status. The quantitative status is evaluated according to the groundwater level and abundance, while the chemical status is assessed based on electrical conductivity, dissolved oxygen, pH levels, nutrient concentrations, specific categories of priority and hazardous substances, and particular pollutants.

For geothermal and mineral waters, the assessment of quantitative status includes groundwater levels or hydrostatic pressure and abundance, whereas the assessment of chemical status includes pollutants such as nitrates and pesticides, as well as the sum of trichloroethylene and tetrachloroethylene concentrations.

The condition of a groundwater body is determined based on groundwater monitoring results, in line with the methodologies set in the River Basin Management Plan. The final classification is based on the poorer of the two (chemical or quantitative status) and can be designated as either good or poor.

Monitoring is also carried out in water areas suitable for freshwater fish habitat, surface waters within catchment areas supplying water for human consumption, vulnerable and sensitive areas, and areas of the ecological network, through the testing of quality elements in protected areas.