Scale issues for setting nutrient standards for small rivers in Latvia. Viesturs. . Saldus. mm 60. I II III IV V Vi VII VIII IX X XI XII

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1 Scale issues for setting nutrient standards for small rivers in Latvia Viesturs Jansons Latvia University of Agriculture, Department of Environmental Engineering and Water Management mm Run-off Water -20 deficiency -30 Normal Year Water Balance Dobele I II III IV V Vi VII VIII IX X XI XII Run-off 168 mm Water deficiency 70 mm mm 60 Precipitation mm Saldus Evapotranspiration mm I II III IV V Vi VII VIII IX X XI XII Run-off 249 mm Water deficiency 66 mm Annual run-off mm (average drainage run-off 200 mm) mm Cēsis I II III IV V Vi VII VIII IX X XI XII Run-off 298 mm Water deficiency 46 mm 1

2 Main drainage areas in Latvia 75% of agriculture land area need regulation of soil moisture conditions (drainage) Subsurface drainage area 1.6 million ha (1990) Up to 95 % drained agricultural land in Central part River basin districts 2

3 Bodies of the Surface Waters in Latvia River water bodies 207 river catchments ( 262 lakes ) 2 types: rhitral rivers (v >0,2 m/s) potomal rivers (v<0,2 m/s) 3 sub types with catchment area : < 100 km2, km2, >1000 km2) Water quality standarts in Latvia Legal standards for surface water quality has been defined for: fish life (NH 4, NH 3, NO 2, NO 3. O 2, BOD, Zn,Cu, SS, t o, etc). drinking water supply (different chemical characteristics) bathing waters (few chemical parameters and biological quality) 3

4 Nutrient standards for rivers in Latvia Recently developed recommendations for river water bodies are based on : Results of the previous monitoring results (since 1977) Water quality Experience and proposals of the other countries e.g. Nutrients for potomal type river water bodies (< 100 km2) High Good Moderate N tot < 1.5 mg/l mg/l > 2.5 mg/l Agricultural land? Small rivers < 10 km 2, drainage channels, P drainage tot < outlets mg/l ? 0.09 < 0.09 mg/l mg/l Agricultural run-off monitoring in Latvia 3 non-point source pollution monitoring stations (sites) Bērze (3,68 catchments, 70 ha drainage field,), intensive farming, cereals and sugar beets, arable land %.). Established 1968 /1994 Mellupīte (9,6 km2 catchment, 13 ha drainage field, 15 plots, average intensity farming, arable land %). Established Vienziemīte (592 ha, low input agriculture, agr. land 79 %, arable land 4-5 %). Established 1948 /1994 4

5 Mellupite monitoring station Small catchment station 15 drainage plots (0.12 ha) Surface runoff plot Crump weir Meteorological station Berze monitoring site Small catchment station 3,68 km 2, Field drainage station - 77 ha, 4 shallow groundwater monitoring wells. Constructed In operation (hydrological data) since Water sampling programme since Renovated measurement structure and new equipment installed in Berze.kmz 5

6 Berze monitoring site Measurement equipment - YSI data loggers, powered from solar panels. GSM data transfer with mobile phone from stations to university PC. Monitoring results Average concentrations of the nitrogen in the run-off 14,00 12,00 NO 3 /N N tot mg/l 11.3 mg/l N/NO3 (Nitrate Directicve) 10,00 8,00 6,00 4,00 2,00 0,00 Plots (unfertilized) Plots (normal) Plots (high) Plots (solid manure) Plots (slurry) Drainage field Small catchment Mellupite monitoring site Drainage field Small catchment Berze monitoring site Drainage field Small catchment Vienziemite monitoring site 6

7 Water quality evaluation in small streams and field drainage US EPA method based on percentile selection of data plotted as frequency distribution is used. (EU JRC publication: A.C. Cardoso et al; "Criteria for the Identification of Freshwaters Subject to Eutrophication) Nutrient concentrations in agricultural drainage 7

8 Nutrient concentrations in agricultural small catchments Berze river basin 8

9 Berze River (June 2007) Nutrient concentrations (N( tot ) in Berze river, small catchment and field drainage Small catchment Berze 25 Frequency Field drainage Berze 10 5 Berze river downstream town 0 0,0 5,0 10,0 15,0 20,0 25,0 30,0 35,0 N tot mg l -1 9

10 Questions / problems discussed in Latvia Does Standards should be developed for river water bodies or for rivers (run-off from agricultural land)? Does Standards should include full scale of water quality classes (excellent(. poor)? Does Standards should be developed taking into account available information (monitoring( monitoring) ) or / and will be adjusted within EU (part of the river in the neighboring EU country with similar conditions). If yes, regional Recommendations? 10