TNMN - TransNational Monitoring Network

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The TransNational Monitoring Network is an important tool under the Danube River Protection Convention (DRPC), whose Contracting Parties are committed to co-operate in the field of monitoring and assessment. Formally launched in 1996, the TNMN aims to provide a well-balanced overall view of pollution and long-term trends in water quality and pollution loads in the major rivers in the Danube River Basin.

a woman in a laboratory

The TransNational Monitoring Network, in short “TNMN” was established to support the implementation of the Danube River Protection Convention in the field of monitoring and assessment utilizing monitoring data assessed at national level. The TNMN was formally launched by the ICPDR in 1996, although the history of international monitoring of the Danube River is much older. The DRPC requires:

  • Harmonising monitoring and assessment methods, particularly concerning water quality in rivers
  • Developing co-ordinated or joint monitoring systems applying stationary or mobile measurement devices, and shared communications and data processing facilities
  • Elaborating and implementing joint programmes for monitoring riverine conditions in the Danube catchment area, including flow rates, water quality, sediments and riverine ecosystems, as a basis for the assessment of transboundary impacts

The main objective of the TNMN is to provide a structured and well-balanced overall view of pollution and long-term trends in water quality and pollution loads in the major rivers of the Danube River Basin.

The collected data is published annually in the TNMN Yearbooks.

In 2006, the TNMN is revised to ensure full compliance with the provisions of the EU Water Framework Directive (WFD).

The TNMN monitoring network derives from national surface water monitoring networks and includes at present 101 monitoring stations with up to three sampling points across the Danube and its main tributaries. The minimum sampling frequency is 12 times per year for chemical determinands in water and twice a year for biological parameters.

The assessment of loads in the Danube River also provides estimates of the influx of polluting substances into the Black Sea, which is a vital information to support policy development. This special load assessment programme was started in 2000, with pollution loads calculated for:  

  • Biochemical Oxygen Demand (BOD)5;
  • Inorganic nitrogen;
  • Ortho-phosphate-phosphorus;
  • Dissolved phosphorus;
  • Total phosphorus;
  • Suspended solids; 
  • And - on a discretionary basis – chlorides.

The assessment of loads into the Black Sea is based on a larger set of substances including heavy metals.