1. Criteria for water quality assessment between countries: how to proceed in the next few years ? F. László Water Resources Research Centre Budapest, Hungary

2. Water quality assessment systems were developed traditionally at national level in the past. The differences are significant between the national water quality assessment systems.

3. Comparison of water quality assessment systems of the Danube countries River Danube length: 2857 km river basin: 817 000 sq.km countries: Germany, Austria, Czech Republic, Slovak Republic, Hungary, Croatia, Slovenia, Republic of Yugoslavia, Bosnia and Herzegovina, Romania, Bulgaria, Moldova, Ukraine population: 82 million mean water discharge at the Danube Delta: 6550 m3/s

4. Orientation map of Danube river basin

5. Comparison of water quality assessment systems of the Danube countries Basic characters of the national systems

6. Comparison of water quality assessment systems of the Danube countries Similarities and differences in limit/target values Limit/target values of oxygen regime parameters are similar in the national assessment/classification systems

7. Comparison of water quality assessment systems of the Danube countries Similarities and differences in limit/target values Big differences in the limits for nutrients, heavy metals, organic micropollutants

8. Comparison of water quality assessment systems of the Danube countries Biological aspects of water quality assessment in the Danube countries

9. Comparison of water quality assessment systems of the Danube countries Assessment of sediment pollution

11. Harmonization of water quality assessment in the scope of Danube River Protection Convention Operation of TransNational Monitoring Network (TNMN) Objectives of TNMN: support the assessment of water quality; support the estimation of pollutant loads; assist in the identification of major pollution sources Sampling sites: stations at or near to state border; stations upstream of confluences of tributaries; stations upstream of major abstraction sites for drinking water supply

12. Operation of TransNational Monitoring Network List of determinands in water: suspended solids, dissolved oxygen, pH, conductivity, alkalinity, ammonium, nitrite, nitrate, organic nitrogen, ortho-phosphate, total phosphorus, sodium, potassium, calcium, magnesium, chloride, sulphate, iron, manganese, zinc, copper, chromium, lead, cadmium, mercury, nickel, arsenic, aluminium, BOD, COD, DOC, phenol index, anion active surfactants, petroleum hydrocarbons, AOX, lindane, pp’-DDT, atrazine, chloroform, carbon tetrachloride, trichloroethene, tetrachloroethene, total coliforms, faecal coliforms, faecal streptococci, salmonella, chlorophyll-a, saprobity index

13. Operation of TransNational Monitoring Network List of determinands in sediment: organic nitrogen, total phosphorus, calcium, magnesium, iron, magnesium, zinc, copper, chromium, lead, cadmium, mercury, nickel, arsenic, aluminium, TOC, petroleum hydrocarbons, total extractable matter, PAHs lindane, pp’-DDT, PCBs

14. Water Framework Directive Biological, chemical and physico-chemical elements for the classification of ecological status composition and abundance of aquatic flora; composition and abundance of benthic invertebrate fauna; composition, abundance and age of structure of fish fauna; thermal conditions; oxygenation conditions; salinity; acidification status; nutrient conditions; specific pollutants

15. Water Framework Directive Priority pollutants alachlor, anthracene, atrazine, benzene, brominated diphenylether, cadmium and its compounds, C-10-13- chloralkanes, chlorfenvinphos, chlorpyrifos, 1,2- dichlormethane,dichlorethane, di(2-ethylhexyl)phtalate, diuron, endosulfan, fluoranthene, hexachlorobenzene, hexachlorobutadiene, hexachlorocyclohexane, isoproturon, lead and its compounds,mercury and its compounds, naphtalene, nickel and its compounds, nonylphenols, octylphenols, pentachlorobenzene, pentachlorophenol, polyaromatic hydrocarbons, simazine, tributyltin ompounds, trichlorobenzenes, trichloromethane, trifluralin

16. How to proceed in the near future ? Involve additional hydrobiological parameters (adaption or development of methods) Focus on priority pollutants (surveys) Continue checking compliance of water quality criteria of different water uses