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River basin

Water pollution in the Bodrog basin

Sites in the 2025 yearbook
40
Failed the standard (80%)
32
Counted in the score
24

River basin overview

In the Bodrog basin the SHMÚ yearbook has 40 monitoring sites; in 2025, 32 of them (80%) failed the standard for at least one indicator. 24 are counted in the scores of the fishing districts.

Year-by-year trend

Share of sites in the river basin that failed the standard

  1. 202235 of 3795%
  2. 202331 of 3589%
  3. 202439 of 5374%
  4. 202532 of 4080%

Fishing district map

Fishing districts of the “Bodrog and Hornád basin” by the nearest SHMÚ site

Detailed filtersregion, district, riverbed, depth, shading, satellites, water chemistry and pollution, fish, geology

1445fishing districts
Pick a category to narrow the selection. Next to each option you can see how many fishing districts remain.
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The color of the fishing district line shows the number of indicators that failed the standard at the nearest SHMÚ site (2025). Gray fishing districts have no site with the same watercourse name nearby. You can also switch the color to groundwater and treatment plants.

Worst sites in the river basin

Click to expand the history by year

  1. Zemplínske HradišteTrnávka, river km 7.55 indicators in 2025
    Indicator2022202320242025
    Oxygen and organic matter
    dissolved oxygen●standard not met●standard not met●standard not met●standard not met
    COD (chemical oxygen demand)●standard not met●standard not met·standard met·standard met
    Nutrients and nitrogen
    ammonium●standard not met●standard not met●standard not met●standard not met
    nitrites●standard not met●standard not met●standard not met●standard not met
    total phosphorus●standard not met●standard not met●standard not met●standard not met
    nitrates·standard met●standard not met·standard met·standard met
    Harmful organic substances
    AOX (adsorbable organic halogens)●standard not met●standard not met●standard not met●standard not met
    petroleum substances (NEL)●standard not met·standard met·standard met·standard met
    Salts, pH and minerals
    calcium·standard met●standard not met·standard met·standard met
    Biology and bacteria
    saprobic index of biosestone●standard not met·standard met·standard met·standard met

    The location of the site is only approximate (based on the water body).

  2. Kyjov, mouthKyjov, river km 0.68 indicators in 2025
    Indicator2022202320242025
    Oxygen and organic matter
    COD (chemical oxygen demand)●standard not met·standard met●standard not met·standard met
    BOD₅ (biochemical oxygen demand)·standard met·standard met●standard not met·standard met
    dissolved oxygen·standard met·standard met●standard not met·standard met
    Nutrients and nitrogen
    total nitrogen●standard not met●standard not met●standard not met●standard not met
    organic nitrogen●standard not met●standard not met●standard not met●standard not met
    nitrites●standard not met·standard met●standard not met●standard not met
    nitrates●standard not met·standard met●standard not met●standard not met
    ammonium●standard not met·standard met●standard not met·standard met
    Harmful organic substances
    AOX (adsorbable organic halogens)·standard met●standard not met●standard not met●standard not met
    petroleum substances (NEL)·standard met●standard not met●standard not met●standard not met
    total cyanides●standard not met·standard met●standard not met·standard met
    Salts, pH and minerals
    dissolved solids, ignited (550 °C)·standard met●standard not met●standard not met●standard not met
    calcium·standard met●standard not met●standard not met●standard not met
    dissolved solids (105 °C)·standard met●standard not met●standard not met·standard met
    conductivity●standard not met·standard met●standard not met·standard met
    chlorides●standard not met·standard met·standard met·standard met
    sulfates·standard met●standard not met·standard met·standard met
    Biology and bacteria
    saprobic index of biosestone·standard met·standard met●standard not met·standard met
    PAHs: 1 substance (not counted in the score)
    Indicator2022202320242025
    PAHs (combustion and deposition)
    fluoranthene●standard not met·standard met●standard not met·standard met

    Polycyclic aromatic hydrocarbons. The standard for benzo(a)pyrene is extremely low (0.17 ng/l), so most streams exceed it; the main sources are combustion and atmospheric deposition.

  3. Slovenské Nové MestoRoňava, river km 2.28 indicators in 2025
    Indicator2022202320242025
    Oxygen and organic matter
    COD (chemical oxygen demand)·standard met●standard not met●standard not met·standard met
    Nutrients and nitrogen
    nitrites●standard not met●standard not met●standard not met●standard not met
    total phosphorus●standard not met·standard met·standard met●standard not met
    Harmful organic substances
    AOX (adsorbable organic halogens)●standard not met●standard not met●standard not met·standard met
    total cyanides·standard met·standard met·standard met●standard not met
    octylphenol●standard not met·standard met·standard met·standard met
    Biology and bacteria
    coliform bacteria●standard not met●standard not met●standard not met●standard not met
    culturable microorganisms (22 °C)●standard not met●standard not met●standard not met●standard not met
    intestinal enterococci●standard not met●standard not met●standard not met●standard not met
    thermotolerant coliform bacteria●standard not met·standard met·standard met●standard not met
    PAHs: 1 substance (not counted in the score)
    Indicator2022202320242025
    PAHs (combustion and deposition)
    benzo(a)pyrene●standard not met●standard not met·standard met●standard not met

    Polycyclic aromatic hydrocarbons. The standard for benzo(a)pyrene is extremely low (0.17 ng/l), so most streams exceed it; the main sources are combustion and atmospheric deposition.

    Nearest site for the fishing districts: Roňava č. 1

    The location of the site is only approximate (based on the water body).

  4. BrehovOndava, river km 4.23 indicators in 2025
    Indicator2022202320242025
    Oxygen and organic matter
    COD (chemical oxygen demand)·standard met●standard not met·standard met●standard not met
    Nutrients and nitrogen
    nitrites●standard not met●standard not met●standard not met●standard not met
    Harmful organic substances
    AOX (adsorbable organic halogens)●standard not met●standard not met●standard not met●standard not met

    The location of the site is only approximate (based on the water body).

  5. Zemplínska Nová Ves – Stanča, road bridgeChlmec, river km 13.54 indicators in 2025
    Indicator2022202320242025
    Oxygen and organic matter
    COD (chemical oxygen demand)–site not in the yearbook–site not in the yearbook●standard not met●standard not met
    dissolved oxygen–site not in the yearbook–site not in the yearbook·standard met●standard not met
    Nutrients and nitrogen
    nitrites–site not in the yearbook–site not in the yearbook●standard not met●standard not met
    total phosphorus–site not in the yearbook–site not in the yearbook●standard not met●standard not met
    nitrates–site not in the yearbook–site not in the yearbook●standard not met·standard met

    The location of the site is only approximate (based on the water body).

  6. PinkovceUh, river km 18.58 indicators in 2025
    Indicator2022202320242025
    Oxygen and organic matter
    dissolved oxygen·standard met·standard met·standard met●standard not met
    Nutrients and nitrogen
    nitrites●standard not met●standard not met●standard not met●standard not met
    ammonium●standard not met·standard met·standard met·standard met
    Harmful organic substances
    petroleum substances (NEL)·standard met●standard not met●standard not met●standard not met
    AOX (adsorbable organic halogens)●standard not met·standard met·standard met·standard met
    heptachlor·standard met·standard met·standard met●standard not met
    PAHs: 5 substances (not counted in the score)
    Indicator2022202320242025
    PAHs (combustion and deposition)
    benzo(a)pyrene●standard not met●standard not met●standard not met●standard not met
    fluoranthene●standard not met●standard not met●standard not met●standard not met
    benzo(b)fluoranthene●standard not met·standard met·standard met●standard not met
    benzo(ghi)perylene·standard met●standard not met●standard not met·standard met
    perylene·standard met·standard met·standard met●standard not met

    Polycyclic aromatic hydrocarbons. The standard for benzo(a)pyrene is extremely low (0.17 ng/l), so most streams exceed it; the main sources are combustion and atmospheric deposition.

    The location of the site is only approximate (based on the water body).

  7. Kopaný Jarok, road bridge Zemplínske Hradište – Hradištská MoľvaKopaný Jarok, river km 4.32 indicators in 2025
    Indicator2022202320242025
    Oxygen and organic matter
    dissolved oxygen–site not in the yearbook–site not in the yearbook●standard not met●standard not met
    COD (chemical oxygen demand)–site not in the yearbook–site not in the yearbook●standard not met·standard met
    total organic carbon–site not in the yearbook–site not in the yearbook●standard not met·standard met
    Nutrients and nitrogen
    ammonium–site not in the yearbook–site not in the yearbook●standard not met●standard not met
    nitrites–site not in the yearbook–site not in the yearbook●standard not met·standard met
    nitrates–site not in the yearbook–site not in the yearbook●standard not met·standard met
    total phosphorus–site not in the yearbook–site not in the yearbook●standard not met·standard met
    Salts, pH and minerals
    conductivity–site not in the yearbook–site not in the yearbook●standard not met·standard met
    calcium–site not in the yearbook–site not in the yearbook●standard not met·standard met
    PAHs: 2 substances (not counted in the score)
    Indicator2022202320242025
    PAHs (combustion and deposition)
    benzo(a)pyrene–site not in the yearbook–site not in the yearbook●standard not met·standard met
    benzo(ghi)perylene–site not in the yearbook–site not in the yearbook●standard not met·standard met

    Polycyclic aromatic hydrocarbons. The standard for benzo(a)pyrene is extremely low (0.17 ng/l), so most streams exceed it; the main sources are combustion and atmospheric deposition.

  8. Zemplínsky BrančChlmec, river km 3.92 indicators in 2025
    Indicator2022202320242025
    Oxygen and organic matter
    COD (chemical oxygen demand)–site not in the yearbook·standard met●standard not met·standard met
    Nutrients and nitrogen
    nitrites–site not in the yearbook●standard not met●standard not met●standard not met
    total phosphorus–site not in the yearbook●standard not met●standard not met●standard not met
    nitrates–site not in the yearbook●standard not met●standard not met·standard met
    Salts, pH and minerals
    calcium–site not in the yearbook●standard not met·standard met·standard met
    PAHs: 1 substance (not counted in the score)
    Indicator2022202320242025
    PAHs (combustion and deposition)
    benzo(a)pyrene–site not in the yearbook●standard not met·standard met·standard met

    Polycyclic aromatic hydrocarbons. The standard for benzo(a)pyrene is extremely low (0.17 ng/l), so most streams exceed it; the main sources are combustion and atmospheric deposition.

    The location of the site is only approximate (based on the water body).

  9. Majerovský P., mouth into the Ondava near KladzanyMajerovský P., river km 0.28 indicators in 2025
    Indicator2022202320242025
    Oxygen and organic matter
    BOD₅ (biochemical oxygen demand)–site not in the yearbook–site not in the yearbook–site not in the yearbook●standard not met
    COD (chemical oxygen demand)–site not in the yearbook–site not in the yearbook–site not in the yearbook●standard not met
    dissolved oxygen–site not in the yearbook–site not in the yearbook–site not in the yearbook●standard not met
    Nutrients and nitrogen
    ammonium–site not in the yearbook–site not in the yearbook–site not in the yearbook●standard not met
    nitrites–site not in the yearbook–site not in the yearbook–site not in the yearbook●standard not met
    total phosphorus–site not in the yearbook–site not in the yearbook–site not in the yearbook●standard not met
    Salts, pH and minerals
    dissolved solids (105 °C)–site not in the yearbook–site not in the yearbook–site not in the yearbook●standard not met
    conductivity–site not in the yearbook–site not in the yearbook–site not in the yearbook●standard not met
  10. Nižný HrušovOndava, river km 42.01 indicator in 2025
    Indicator2022202320242025
    Oxygen and organic matter
    dissolved oxygen●standard not met·standard met·standard met·standard met
    Nutrients and nitrogen
    nitrites●standard not met●standard not met●standard not met●standard not met
    Harmful organic substances
    AOX (adsorbable organic halogens)●standard not met●standard not met●standard not met·standard met
    petroleum substances (NEL)●standard not met·standard met·standard met·standard met
    Biology and bacteria
    saprobic index of biosestone●standard not met●standard not met·standard met·standard met
    PAHs: 1 substance (not counted in the score)
    Indicator2022202320242025
    PAHs (combustion and deposition)
    benzo(a)pyrene·standard met●standard not met·standard met·standard met

    Polycyclic aromatic hydrocarbons. The standard for benzo(a)pyrene is extremely low (0.17 ng/l), so most streams exceed it; the main sources are combustion and atmospheric deposition.

    Nearest site for the fishing districts: Ondava č. 1, VN Nižný Hrušov

  11. Streda nad BodrogomBodrog, river km 5.07 indicators in 2025
    Indicator2022202320242025
    Oxygen and organic matter
    COD (chemical oxygen demand)·standard met·standard met●standard not met·standard met
    Nutrients and nitrogen
    nitrites●standard not met●standard not met●standard not met●standard not met
    Harmful organic substances
    AOX (adsorbable organic halogens)●standard not met●standard not met·standard met·standard met
    Biology and bacteria
    culturable microorganisms (22 °C)●standard not met●standard not met●standard not met●standard not met
    coliform bacteria·standard met●standard not met●standard not met●standard not met
    thermotolerant coliform bacteria·standard met●standard not met●standard not met●standard not met
    intestinal enterococci●standard not met●standard not met·standard met●standard not met
    saprobic index of biosestone●standard not met·standard met·standard met·standard met
    PAHs: 2 substances (not counted in the score)
    Indicator2022202320242025
    PAHs (combustion and deposition)
    benzo(a)pyrene●standard not met●standard not met●standard not met●standard not met
    fluoranthene●standard not met·standard met●standard not met●standard not met

    Polycyclic aromatic hydrocarbons. The standard for benzo(a)pyrene is extremely low (0.17 ng/l), so most streams exceed it; the main sources are combustion and atmospheric deposition.

    Nearest site for the fishing districts: Bodrog č. 1a, Bodrog č. 1b

    The location of the site is only approximate (based on the water body).

  12. ČičarovceUdoč, river km 2.99 indicators in 2024
    Indicator2022202320242025
    Oxygen and organic matter
    BOD₅ (biochemical oxygen demand)–site not in the yearbook–site not in the yearbook●standard not met–site not in the yearbook
    COD (chemical oxygen demand)–site not in the yearbook–site not in the yearbook●standard not met–site not in the yearbook
    total organic carbon–site not in the yearbook–site not in the yearbook●standard not met–site not in the yearbook
    dissolved oxygen–site not in the yearbook–site not in the yearbook●standard not met–site not in the yearbook
    Nutrients and nitrogen
    nitrites–site not in the yearbook–site not in the yearbook●standard not met–site not in the yearbook
    total phosphorus–site not in the yearbook–site not in the yearbook●standard not met–site not in the yearbook
    PAHs: 3 substances (not counted in the score)
    Indicator2022202320242025
    PAHs (combustion and deposition)
    benzo(a)pyrene–site not in the yearbook–site not in the yearbook●standard not met–site not in the yearbook
    benzo(ghi)perylene–site not in the yearbook–site not in the yearbook●standard not met–site not in the yearbook
    fluoranthene–site not in the yearbook–site not in the yearbook●standard not met–site not in the yearbook

    Polycyclic aromatic hydrocarbons. The standard for benzo(a)pyrene is extremely low (0.17 ng/l), so most streams exceed it; the main sources are combustion and atmospheric deposition.

    The location of the site is only approximate (based on the water body).

  13. Ortov, belowOrtov, river km 6.06 indicators in 2024
    Indicator2022202320242025
    Oxygen and organic matter
    COD (chemical oxygen demand)–site not in the yearbook–site not in the yearbook●standard not met–site not in the yearbook
    total organic carbon–site not in the yearbook–site not in the yearbook●standard not met–site not in the yearbook
    dissolved oxygen–site not in the yearbook–site not in the yearbook●standard not met–site not in the yearbook
    Nutrients and nitrogen
    nitrites–site not in the yearbook–site not in the yearbook●standard not met–site not in the yearbook
    total phosphorus–site not in the yearbook–site not in the yearbook●standard not met–site not in the yearbook
    PAHs: 1 substance (not counted in the score)
    Indicator2022202320242025
    PAHs (combustion and deposition)
    benzo(a)pyrene–site not in the yearbook–site not in the yearbook●standard not met–site not in the yearbook

    Polycyclic aromatic hydrocarbons. The standard for benzo(a)pyrene is extremely low (0.17 ng/l), so most streams exceed it; the main sources are combustion and atmospheric deposition.

    Nearest site for the fishing districts: Jazero Ortov

  14. LelesLatorica, river km 21.33 indicators in 2025
    Indicator2022202320242025
    Nutrients and nitrogen
    nitrites●standard not met●standard not met●standard not met●standard not met
    Harmful organic substances
    AOX (adsorbable organic halogens)●standard not met·standard met●standard not met·standard met
    Biology and bacteria
    saprobic index of biosestone●standard not met·standard met·standard met·standard met
    PAHs: 4 substances (not counted in the score)
    Indicator2022202320242025
    PAHs (combustion and deposition)
    benzo(a)pyrene●standard not met●standard not met●standard not met●standard not met
    fluoranthene●standard not met·standard met●standard not met●standard not met
    benzo(ghi)perylene●standard not met·standard met●standard not met·standard met
    anthracene●standard not met·standard met·standard met·standard met

    Polycyclic aromatic hydrocarbons. The standard for benzo(a)pyrene is extremely low (0.17 ng/l), so most streams exceed it; the main sources are combustion and atmospheric deposition.

    Nearest site for the fishing districts: Latorica č. 1, Latorica č. 2, Latorica č. 3, Latorica č. 4

    The location of the site is only approximate (based on the water body).

  15. LastomírLaborec, river km 31.01 indicator in 2025
    Indicator2022202320242025
    Nutrients and nitrogen
    nitrites●standard not met●standard not met●standard not met●standard not met
    Harmful organic substances
    AOX (adsorbable organic halogens)●standard not met●standard not met·standard met·standard met

    The location of the site is only approximate (based on the water body).

  16. SomotorSomotorský K., river km 3.64 indicators in 2025
    Indicator2022202320242025
    Oxygen and organic matter
    COD (chemical oxygen demand)–site not in the yearbook–site not in the yearbook–site not in the yearbook●standard not met
    dissolved oxygen–site not in the yearbook–site not in the yearbook–site not in the yearbook●standard not met
    Nutrients and nitrogen
    total phosphorus–site not in the yearbook–site not in the yearbook–site not in the yearbook●standard not met
    PAHs: 1 substance (not counted in the score)
    Indicator2022202320242025
    PAHs (combustion and deposition)
    benzo(a)pyrene–site not in the yearbook–site not in the yearbook–site not in the yearbook●standard not met

    Polycyclic aromatic hydrocarbons. The standard for benzo(a)pyrene is extremely low (0.17 ng/l), so most streams exceed it; the main sources are combustion and atmospheric deposition.

    Nearest site for the fishing districts: Somotorský kanál

  17. Petrovce nad LaborcomLaborec, river km 45.13 indicators in 2025
    Indicator2022202320242025
    Nutrients and nitrogen
    nitrites●standard not met●standard not met–site not in the yearbook●standard not met
    Harmful organic substances
    AOX (adsorbable organic halogens)·standard met·standard met–site not in the yearbook●standard not met
    PFOS (perfluorooctane sulfonate)·standard met·standard met–site not in the yearbook●standard not met

    The location of the site is only approximate (based on the water body).

  18. IžkovceLaborec, river km 10.33 indicators in 2025
    Indicator2022202320242025
    Nutrients and nitrogen
    nitrites●standard not met●standard not met●standard not met●standard not met
    Harmful organic substances
    petroleum substances (NEL)●standard not met·standard met·standard met·standard met
    PAHs: 3 substances (not counted in the score)
    Indicator2022202320242025
    PAHs (combustion and deposition)
    benzo(a)pyrene·standard met●standard not met·standard met●standard not met
    fluoranthene·standard met●standard not met·standard met●standard not met
    benzo(ghi)perylene·standard met●standard not met·standard met·standard met

    Polycyclic aromatic hydrocarbons. The standard for benzo(a)pyrene is extremely low (0.17 ng/l), so most streams exceed it; the main sources are combustion and atmospheric deposition.

    Nearest site for the fishing districts: Laborec č. 1

    The location of the site is only approximate (based on the water body).

  19. Lieskovčík, mouthLieskovčík, river km 0.29 indicators in 2023
    Indicator2022202320242025
    Oxygen and organic matter
    BOD₅ (biochemical oxygen demand)–site not in the yearbook●standard not met–site not in the yearbook–site not in the yearbook
    COD (chemical oxygen demand)–site not in the yearbook●standard not met–site not in the yearbook–site not in the yearbook
    dissolved oxygen–site not in the yearbook●standard not met–site not in the yearbook–site not in the yearbook
    Nutrients and nitrogen
    ammonium–site not in the yearbook●standard not met–site not in the yearbook–site not in the yearbook
    nitrites–site not in the yearbook●standard not met–site not in the yearbook–site not in the yearbook
    nitrates–site not in the yearbook●standard not met–site not in the yearbook–site not in the yearbook
    total phosphorus–site not in the yearbook●standard not met–site not in the yearbook–site not in the yearbook
    Salts, pH and minerals
    conductivity–site not in the yearbook●standard not met–site not in the yearbook–site not in the yearbook
    Biology and bacteria
    saprobic index of biosestone–site not in the yearbook●standard not met–site not in the yearbook–site not in the yearbook
  20. Domaša Reservoir, inflowOndava, river km 91.40 indicators in 2025
    Indicator2022202320242025
    Nutrients and nitrogen
    nitrites●standard not met●standard not met●standard not met·standard met
    Harmful organic substances
    AOX (adsorbable organic halogens)●standard not met·standard met●standard not met·standard met
    petroleum substances (NEL)●standard not met·standard met·standard met·standard met

    Nearest site for the fishing districts: VN Domaša

    The location of the site is only approximate (based on the water body).

  • standard not met
  • no unmet standard
  • site not in the yearbook

Fishing districts near these sites

Fishing districts whose nearest SHMÚ site lies in this river basin

  • Roňava č. 1site Slovenské Nové Mesto · standard not met in 4 of 4 years · nitrates in the groundwater nearby 39.6 mg/l8 indicators
  • Laborec č. 2site Cirocha, above · standard not met in 1 of 4 years · nitrates in the groundwater nearby 4.7 mg/l8 indicators
  • Laborec č. 3site Cirocha, above · standard not met in 1 of 4 years · nitrates in the groundwater nearby 0.5 mg/l8 indicators
  • Bodrog č. 1asite Streda nad Bodrogom · standard not met in 4 of 4 years · nitrates in the groundwater nearby 39.6 mg/l7 indicators
  • Bodrog č. 1bsite Streda nad Bodrogom · standard not met in 4 of 4 years · nitrates in the groundwater nearby 33.9 mg/l7 indicators
  • Jazero Ortovsite Ortov, below · standard not met in 1 of 4 years · nitrates in the groundwater nearby 4.3 mg/l6 indicators
  • Trnávka č. 1site Vojčice · standard not met in 1 of 4 years · nitrates in the groundwater nearby 42.5 mg/l5 indicators
  • Trnávka č. 2site Vojčice · standard not met in 1 of 4 years · nitrates in the groundwater nearby 0.5 mg/l5 indicators
  • OR Veľké Raškovcesite Veľké Raškovce, above · standard not met in 1 of 4 years · nitrates in the groundwater nearby 1.7 mg/l4 indicators
  • Sobranecký potok č. 1site Sobrance, Komárovce part · standard not met in 1 of 4 years · nitrates in the groundwater nearby 0.5 mg/l4 indicators
  • Sobranecký potok č. 2site Sobrance, Komárovce part · standard not met in 1 of 4 years · nitrates in the groundwater nearby 2.4 mg/l4 indicators
  • Somotorský kanálsite Somotor · standard not met in 1 of 4 years · nitrates in the groundwater nearby 0.5 mg/l4 indicators
  • Šibská vodasite Bardejov, mouth – bridge · standard not met in 1 of 4 years · nitrates in the groundwater nearby 0.5 mg/l4 indicators
  • Laborec č. 1site Ižkovce · standard not met in 4 of 4 years · nitrates in the groundwater nearby 0.5 mg/l3 indicators
  • Latorica č. 1site Leles · standard not met in 4 of 4 years · nitrates in the groundwater nearby 1.7 mg/l3 indicators
  • Latorica č. 2site Leles · standard not met in 4 of 4 years · nitrates in the groundwater nearby 1.7 mg/l3 indicators
  • Latorica č. 3site Leles · standard not met in 4 of 4 years · nitrates in the groundwater nearby 0.5 mg/l3 indicators
  • Latorica č. 4site Leles · standard not met in 4 of 4 years · nitrates in the groundwater nearby 0.5 mg/l3 indicators
  • Ondavka č. 1site Tovarnianska Polianka · standard not met in 1 of 4 years · nitrates in the groundwater nearby 1.2 mg/l3 indicators
  • Ondavka č. 2site Tovarnianska Polianka · standard not met in 1 of 4 years · nitrates in the groundwater nearby 0.5 mg/l3 indicators
  • Oľka č. 1site Jasenovce, bridge above · standard not met in 1 of 4 years · nitrates in the groundwater nearby 1.6 mg/l3 indicators
  • Oľka č. 2site Jasenovce, bridge above · standard not met in 1 of 4 years · nitrates in the groundwater nearby 7.3 mg/l3 indicators
  • Radomkasite Radomka, mouth · standard not met in 1 of 4 years · nitrates in the groundwater nearby 4.1 mg/l3 indicators
  • Topľa č. 5bsite Malcov, above · standard not met in 1 of 4 years · nitrates in the groundwater nearby 0.5 mg/l3 indicators
  • Topľa č. 6site Malcov, above · standard not met in 1 of 4 years · nitrates in the groundwater nearby 3.8 mg/l3 indicators
  • Topľa č. 7site Malcov, above · standard not met in 1 of 4 years · nitrates in the groundwater nearby 3.8 mg/l3 indicators
  • VN Danovasite Kryštálový potok, above · standard not met in 1 of 4 years3 indicators
  • VN Starina – prítokysite Starina Reservoir, inflow · standard not met in 1 of 4 years · nitrates in the groundwater nearby 10.7 mg/l3 indicators
  • Topľa č. 1site Božčice · standard not met in 2 of 4 years · nitrates in the groundwater nearby 0.5 mg/l2 indicators
  • Topľa č. 2site Božčice · standard not met in 2 of 4 years · nitrates in the groundwater nearby 29.2 mg/l2 indicators
  • Ondava č. 6site Nižný Mirošov · standard not met in 1 of 4 years · nitrates in the groundwater nearby 4.1 mg/l2 indicators
  • Orechovský potoksite Koromľa, above · standard not met in 1 of 4 years · nitrates in the groundwater nearby 0.5 mg/l2 indicators
  • OR Vysoká nad Uhomsite Uh, road bridge Vysoká nad Uhom · standard not met in 1 of 4 years · nitrates in the groundwater nearby 0.5 mg/l2 indicators
  • Pčolinka č.1site Snina · standard not met in 1 of 4 years · nitrates in the groundwater nearby 22.4 mg/l2 indicators
  • Pčolinka č.2site Snina · standard not met in 1 of 4 years · nitrates in the groundwater nearby 10.7 mg/l2 indicators
  • VN Byštasite VN Byšta, below · standard not met in 1 of 4 years · nitrates in the groundwater nearby 9.5 mg/l2 indicators
  • Výravasite Jabloň · standard not met in 1 of 4 years · nitrates in the groundwater nearby 1.1 mg/l2 indicators
  • Ondava č. 1site Nižný Hrušov · standard not met in 4 of 4 years · nitrates in the groundwater nearby 0.5 mg/l1 indicator
  • Uličkasite Ulička, state border · standard not met in 4 of 4 years1 indicator
  • VN Nižný Hrušovsite Nižný Hrušov · standard not met in 4 of 4 years · nitrates in the groundwater nearby 11.8 mg/l1 indicator

Showing 40 of 62 fishing districts, worst first.

What most often fails

Number of sites in the river basin that failed this indicator in 2025

  1. nitritesNutrients and nitrogen22
  2. benzo(a)pyrenePAHs (combustion and deposition)20
  3. dissolved oxygenOxygen and organic matter7
  4. total phosphorusNutrients and nitrogen7
  5. COD (chemical oxygen demand)Oxygen and organic matter6
  6. fluoranthenePAHs (combustion and deposition)5
  7. AOX (adsorbable organic halogens)Harmful organic substances4
  8. calciumSalts, pH and minerals3
  9. ammoniumNutrients and nitrogen3
  10. petroleum substances (NEL)Harmful organic substances2
  11. coliform bacteriaBiology and bacteria2
  12. thermotolerant coliform bacteriaBiology and bacteria2
  • counted in the fishing district score
  • shown, not counted in the score

Where the data come from and what they do not say

  • Surface waters: yearbooks of the Slovak Hydrometeorological Institute (SHMÚ) Surface Water Quality for the years 2022 to 2025. We transcribed the list of sites and indicators that failed the standard under Government Regulation no. 269/2010 Coll. into a table in the plugin. Older yearbooks are in a different format and we did not include them.
  • Groundwater: SHMÚ yearbooks Groundwater Quality, stations and indicators exceeded in 2017 to 2025 according to the drinking-water limits. The connection to the fishing district is only indirect.
  • Groundwater, measured values: the public SHMÚ interface "Groundwater quality monitoring results". We have actually measured values (nitrates, ammonium, iron, chlorides, metals, pesticides, PFAS, solvents) for 758 stations; for each substance we take the highest value from the samples in 2025 (for stations without data for that year, from one of the two previous years). A value equal to the standard counts as an exceedance, as it does at SHMÚ.
  • Treatment plants: register of wastewater treatment plants (VÚVH, EEA) from the "Points near fishing districts" file, that is, only plants within 2 km of the fishing district line. There are considerably more treatment plants in Slovakia.

What this data does not say. The yearbook lists the sites that failed the standard. A site missing from it is not proof of clean water, so the score of a fishing district is only ever lowered and never raised. We did not include industrial polluters (the National Pollution Register) in the list because the register was unavailable when the data was collected, and for wastewater treatment plants we list only those we found near the fishing districts. Only 31% of SHMÚ sites have an exact location, 47% have only an approximate location (based on the water body, so they count less near the districts) and 22% have no location at all, so we do not assign them to any district. We determine the distance, the match of the watercourse name and the ranking ourselves; the assignment is indicative.