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River basin

Water pollution in the Nitra basin

Sites in the 2025 yearbook
37
Failed the standard (86%)
32
Counted in the score
25

River basin overview

In the Nitra basin the SHMÚ yearbook has 37 monitoring sites; in 2025, 32 of them (86%) failed the standard for at least one indicator. 25 are counted in the scores of the fishing districts.

Watercourse profile of Nitra

SHMÚ sites from source to mouth

Watercourse profile from source to mouthnumber of unmet indicators in 2025 at SHMÚ sites

012345Kľačno, above, river km 165.0: no failed standard (2025)Nedožery, river km 149.0: 3 indicators (2025)Chalmová, river km 123.8: 5 indicators (2025)Nitrianska Streda, river km 91.1: no failed standard (2025)below the inlet of the Janíkovský canal, river km 50.1: no failed standard (2024)Čechynce, river km 47.8: 1 indicator (2025)Nové Zámky, Berek part, river km 9.8: 4 indicators (2024)Komoča, river km 6.5: 1 indicator (2025)river km 165 (upper course)river km 7 (towards the mouth)
Show sites in the table (8)
  • Kľačno, aboveriver km 165.0no unmet standard
  • Nedožeryriver km 149.03 indicators
  • Chalmováriver km 123.85 indicators
  • Nitrianska Stredariver km 91.1no unmet standard
  • below the inlet of the Janíkovský canalriver km 50.1no unmet standard
  • Čechynceriver km 47.81 indicator
  • Nové Zámky, Berek partriver km 9.84 indicators
  • Komočariver km 6.51 indicator
  • standard not met
  • no unmet standard
  • site not in the yearbook

Year-by-year trend

Share of sites in the river basin that failed the standard

  1. 202245 of 45100%
  2. 202339 of 4391%
  3. 202449 of 5589%
  4. 202532 of 3786%

Fishing district map

Fishing districts in the “Danube river basin” by 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. Topoľčny, road bridge to KrušovceBedziansky P., river km 1.47 indicators in 2025
    Indicator2022202320242025
    Oxygen and organic matter
    BOD₅ (biochemical oxygen demand)–site not in the yearbook●standard not met●standard not met●standard not met
    COD (chemical oxygen demand)–site not in the yearbook●standard not met●standard not met●standard not met
    dissolved oxygen–site not in the yearbook●standard not met●standard not met·standard met
    total organic carbon–site not in the yearbook●standard not met·standard met·standard met
    Nutrients and nitrogen
    total phosphorus–site not in the yearbook●standard not met●standard not met●standard not met
    ammonium–site not in the yearbook●standard not met●standard not met·standard met
    nitrites–site not in the yearbook●standard not met●standard not met·standard met
    total nitrogen–site not in the yearbook●standard not met●standard not met·standard met
    Harmful organic substances
    heptachlor–site not in the yearbook●standard not met·standard met·standard met
    Salts, pH and minerals
    conductivity–site not in the yearbook●standard not met·standard met·standard met
    calcium–site not in the yearbook●standard not met·standard met·standard met
    PAHs: 4 substances (not counted in the score)
    Indicator2022202320242025
    PAHs (combustion and deposition)
    benzo(a)pyrene–site not in the yearbook●standard not met·standard met●standard not met
    fluoranthene–site not in the yearbook●standard not met·standard met●standard not met
    benzo(b)fluoranthene–site not in the yearbook·standard met·standard met●standard not met
    benzo(k)fluoranthene–site not in the yearbook·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).

  2. Poľný Kesov, below (above the Rastislavice Reservoir)Cabajský potok, river km 10.87 indicators in 2025
    Indicator2022202320242025
    Oxygen and organic matter
    BOD₅ (biochemical oxygen demand)●standard not met●standard not met●standard not met●standard not met
    COD (chemical oxygen demand)●standard not met●standard not met●standard not met●standard not met
    dissolved oxygen●standard not met·standard met●standard not met·standard met
    Nutrients and nitrogen
    nitrates●standard not met●standard not met·standard met●standard not met
    total nitrogen●standard not met●standard not met·standard met●standard not met
    total phosphorus●standard not met●standard not met·standard met●standard not met
    ammonium·standard met●standard not met·standard met·standard met
    Harmful organic substances
    total cyanides●standard not met·standard met·standard met·standard met
    Salts, pH and minerals
    conductivity●standard not met●standard not met●standard not met●standard not met
    chlorides●standard not met●standard not met·standard met·standard met
    dissolved solids, ignited (550 °C)●standard not met●standard not met·standard met·standard met
    pH·standard met·standard met·standard met●standard not met
    dissolved solids (105 °C)●standard not met·standard met·standard met·standard met

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

  3. HulŽitava, river km 3.57 indicators in 2025
    Indicator2022202320242025
    Oxygen and organic matter
    BOD₅ (biochemical oxygen demand)·standard met●standard not met·standard met·standard met
    Nutrients and nitrogen
    total phosphorus●standard not met●standard not met●standard not met●standard not met
    nitrites●standard not 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
    Salts, pH and minerals
    conductivity●standard not met·standard met●standard not met●standard not met
    pH●standard not met●standard not met·standard met·standard met
    chlorides·standard met·standard met·standard met●standard not met
    calcium·standard met·standard met·standard met●standard not met
    Biology and bacteria
    saprobic index of biosestone●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 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.

    Nearest site for the fishing districts: Žitava č. 1, Žitava kanál č. 1, Žitava č. 2, Žitava č. 3

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

  4. HulLiska, river km 0.68 indicators in 2025
    Indicator2022202320242025
    Oxygen and organic matter
    BOD₅ (biochemical oxygen demand)●standard not met–site not in the yearbook·standard met●standard not met
    COD (chemical oxygen demand)●standard not met–site not in the yearbook·standard met●standard not met
    Nutrients and nitrogen
    nitrates●standard not met–site not in the yearbook●standard not met●standard not met
    total nitrogen●standard not met–site not in the yearbook●standard not met●standard not met
    total phosphorus●standard not met–site not in the yearbook●standard not met●standard not met
    nitrites●standard not met–site not in the yearbook·standard met·standard met
    Metals
    arsenic●standard not met–site not in the yearbook●standard not met·standard met
    Salts, pH and minerals
    chlorides●standard not met–site not in the yearbook●standard not met●standard not met
    conductivity●standard not met–site not in the yearbook●standard not met●standard not met
    calcium●standard not met–site not in the yearbook●standard not met·standard met
    pH·standard met–site not in the yearbook●standard not met·standard met
    Biology and bacteria
    phytoplankton abundance●standard not met–site not in the yearbook·standard met·standard met
    chlorophyll a●standard not met–site not in the yearbook·standard met·standard met
    saprobic index of biosestone·standard met–site not in the yearbook·standard met●standard not met
    PAHs: 1 substance (not counted in the score)
    Indicator2022202320242025
    PAHs (combustion and deposition)
    benzo(a)pyrene●standard not met–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.

  5. AndovceDlhý Kanál, river km 0.16 indicators in 2025
    Indicator2022202320242025
    Oxygen and organic matter
    BOD₅ (biochemical oxygen demand)–site not in the yearbook●standard not met●standard not met●standard not met
    COD (chemical oxygen demand)–site not in the yearbook●standard not met●standard not met●standard not met
    dissolved oxygen–site not in the yearbook●standard not met·standard met·standard met
    Nutrients and nitrogen
    nitrates–site not in the yearbook●standard not met·standard met●standard not met
    total phosphorus–site not in the yearbook●standard not met·standard met●standard not met
    Salts, pH and minerals
    conductivity–site not in the yearbook●standard not met●standard not met●standard not met
    chlorides–site not in the yearbook●standard not met·standard met●standard not met
    pH–site not in the yearbook●standard not met●standard not met·standard met
    Biology and bacteria
    chlorophyll a–site not in the yearbook●standard not met●standard not met·standard met
    phytoplankton abundance–site not in the yearbook●standard not met·standard met·standard met
  6. Poľný Kesov, aboveCabajský potok, river km 13.58 indicators in 2024
    Indicator2022202320242025
    Oxygen and organic matter
    BOD₅ (biochemical oxygen demand)●standard not met●standard not met●standard not met–site not in the yearbook
    COD (chemical oxygen demand)●standard not met●standard not met●standard not met–site not in the yearbook
    Nutrients and nitrogen
    ammonium●standard not met●standard not met●standard not met–site not in the yearbook
    nitrates●standard not met●standard not met●standard not met–site not in the yearbook
    total nitrogen●standard not met●standard not met●standard not met–site not in the yearbook
    total phosphorus●standard not met●standard not met●standard not met–site not in the yearbook
    Harmful organic substances
    total cyanides●standard not met·standard met·standard met–site not in the yearbook
    Salts, pH and minerals
    conductivity●standard not met●standard not met●standard not met–site not in the yearbook
    calcium●standard not met●standard not met●standard not met–site not in the yearbook
    dissolved solids, ignited (550 °C)●standard not met●standard not met·standard met–site not in the yearbook
    dissolved solids (105 °C)●standard not met·standard met·standard met–site not in the yearbook
    PAHs: 2 substances (not counted in the score)
    Indicator2022202320242025
    PAHs (combustion and deposition)
    benzo(a)pyrene·standard met●standard not met·standard met–site not in the yearbook
    fluoranthene·standard met●standard not met·standard 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.

  7. ChalmováNitra, river km 123.85 indicators in 2025
    Indicator2022202320242025
    Oxygen and organic matter
    BOD₅ (biochemical oxygen demand)●standard not met·standard met·standard met●standard not met
    Nutrients and nitrogen
    nitrites●standard not met●standard not met●standard not met·standard met
    total phosphorus·standard met●standard not met·standard met·standard met
    Metals
    arsenic●standard not 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
    PFOS (perfluorooctane sulfonate)·standard met·standard met·standard met●standard not met
    Salts, pH and minerals
    pH●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 met●standard not met·standard met●standard not met
    fluoranthene·standard 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: Nitra č. 5a, Nitra č. 6a

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

  8. AndačAndac, river km 2.06 indicators in 2025
    Indicator2022202320242025
    Oxygen and organic matter
    BOD₅ (biochemical oxygen demand)–site not in the yearbook●standard not met–site not in the yearbook●standard not met
    COD (chemical oxygen demand)–site not in the yearbook●standard not met–site not in the yearbook●standard not met
    dissolved oxygen–site not in the yearbook●standard not met–site not in the yearbook·standard met
    Nutrients and nitrogen
    nitrates–site not in the yearbook●standard not met–site not in the yearbook●standard not met
    total nitrogen–site not in the yearbook●standard not met–site not in the yearbook●standard not met
    total phosphorus–site not in the yearbook●standard not met–site not in the yearbook●standard not met
    Metals
    lead–site not in the yearbook●standard not met–site not in the yearbook·standard met
    Harmful organic substances
    octylphenol–site not in the yearbook●standard not met–site not in the yearbook·standard met
    Salts, pH and minerals
    conductivity–site not in the yearbook●standard not met–site not in the yearbook●standard not met
    calcium–site not in the yearbook●standard not met–site not in the yearbook·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–site not in the yearbook·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. KošHandlovka, river km 1.21 indicator in 2025
    Indicator2022202320242025
    Oxygen and organic matter
    BOD₅ (biochemical oxygen demand)●standard not met·standard met·standard met·standard met
    COD (chemical oxygen demand)●standard not met·standard met·standard met·standard met
    Nutrients and nitrogen
    total phosphorus●standard not met●standard not met●standard not met●standard not met
    nitrites·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 met

    Nearest site for the fishing districts: Handlovka č. 1

  10. Dlhý Kanál, road bridge Trnovec nad Váhom-JatovDlhý Kanál, river km 22.010 indicators in 2025
    Indicator2022202320242025
    Oxygen and organic matter
    BOD₅ (biochemical oxygen demand)–site not in the yearbook–site not in the yearbook·standard met●standard not met
    COD (chemical oxygen demand)–site not in the yearbook–site not in the yearbook·standard met●standard not met
    total organic carbon–site not in the yearbook–site not in the yearbook·standard met●standard not met
    dissolved oxygen–site not in the yearbook–site not in the yearbook·standard met●standard not met
    Nutrients and nitrogen
    nitrates–site not in the yearbook–site not in the yearbook●standard not met●standard not met
    total nitrogen–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
    Salts, pH and minerals
    conductivity–site not in the yearbook–site not in the yearbook●standard not met●standard not 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 met●standard not met
    perylene–site not in the yearbook–site not in the yearbook·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).

  11. VrábleHostovský potok, river km 0.712 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
    Nutrients and nitrogen
    ammonium–site not in the yearbook–site not in the yearbook●standard not met–site not in the yearbook
    total nitrogen–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
    Harmful organic substances
    6-tBTP–site not in the yearbook–site not in the yearbook●standard not met–site not in the yearbook
    Salts, pH and minerals
    pH–site not in the yearbook–site not in the yearbook●standard not met–site not in the yearbook
    conductivity–site not in the yearbook–site not in the yearbook●standard not met–site not in the yearbook
    calcium–site not in the yearbook–site not in the yearbook●standard not met–site not in the yearbook
    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–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.

  12. Baratsko -majereBocegaj, river km 5.58 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
    Nutrients and nitrogen
    ammonium–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
    Salts, pH and minerals
    calcium–site not in the yearbook–site not in the yearbook●standard not met–site not in the yearbook
    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–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. Podhájska below, bridge near the greenhousesLiska, river km 6.84 indicators in 2024
    Indicator2022202320242025
    Oxygen and organic matter
    BOD₅ (biochemical oxygen demand)●standard not met·standard met·standard met–site not in the yearbook
    COD (chemical oxygen demand)·standard met●standard not met·standard met–site not in the yearbook
    Nutrients and nitrogen
    nitrates●standard not met●standard not met·standard met–site not in the yearbook
    total phosphorus●standard not met●standard not met·standard met–site not in the yearbook
    Harmful organic substances
    AOX (adsorbable organic halogens)●standard not met●standard not met●standard not met–site not in the yearbook
    total cyanides●standard not met·standard met·standard met–site not in the yearbook
    Salts, pH and minerals
    conductivity●standard not met●standard not met●standard not met–site not in the yearbook
    chlorides●standard not met●standard not met·standard met–site not in the yearbook
    dissolved solids (105 °C)●standard not met●standard not met·standard met–site not in the yearbook
    dissolved solids, ignited (550 °C)●standard not met●standard not met·standard met–site not in the yearbook
    pH·standard met·standard met●standard not met–site not in the yearbook
    calcium·standard met·standard met●standard not met–site not in the yearbook
    Biology and bacteria
    saprobic index of biosestone●standard not met●standard not met·standard met–site not in the yearbook

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

  14. Mochovce bridge, belowTelinský p., river km 13.81 indicator in 2025
    Indicator2022202320242025
    Oxygen and organic matter
    BOD₅ (biochemical oxygen demand)·standard met●standard not met·standard met·standard met
    COD (chemical oxygen demand)·standard met●standard not met·standard met·standard met
    Nutrients and nitrogen
    total phosphorus●standard not met●standard not met●standard not met●standard not met
    nitrates●standard not met·standard met·standard met·standard met
    Salts, pH and minerals
    pH●standard not met·standard met·standard met·standard met
    calcium·standard met·standard met●standard not met·standard met
  15. KomočaNitra, river km 6.51 indicator in 2025
    Indicator2022202320242025
    Nutrients and nitrogen
    nitrites·standard met●standard not met·standard met·standard met
    total phosphorus·standard met●standard not met·standard met·standard met
    Metals
    arsenic·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
    Salts, pH and minerals
    pH●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 met●standard not met·standard met
    fluoranthene·standard 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.

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

  16. PalárikovoDlhý Kanál, river km 8.04 indicators in 2025
    Indicator2022202320242025
    Oxygen and organic matter
    BOD₅ (biochemical oxygen demand)–site not in the yearbook–site not in the yearbook●standard not met·standard met
    COD (chemical oxygen demand)–site not in the yearbook–site not in the yearbook●standard not met·standard met
    Nutrients and nitrogen
    nitrates–site not in the yearbook–site not in the yearbook●standard not met●standard not met
    total nitrogen–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
    Salts, pH and minerals
    chlorides–site not in the yearbook–site not in the yearbook●standard not met●standard not met
    pH–site not in the yearbook–site not in the yearbook●standard not met·standard met
    conductivity–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).

  17. VrábleKováčovský potok, river km 0.79 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
    Nutrients and nitrogen
    nitrites–site not in the yearbook–site not in the yearbook●standard not met–site not in the yearbook
    nitrates–site not in the yearbook–site not in the yearbook●standard not met–site not in the yearbook
    total nitrogen–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
    Salts, pH and minerals
    pH–site not in the yearbook–site not in the yearbook●standard not met–site not in the yearbook
    conductivity–site not in the yearbook–site not in the yearbook●standard not met–site not in the yearbook
    calcium–site not in the yearbook–site not in the yearbook●standard not met–site not in the yearbook
  18. Road bridge – Dežerice – VlčkovoMachnáč, river km 2.67 indicators in 2025
    Indicator2022202320242025
    Oxygen and organic matter
    BOD₅ (biochemical oxygen demand)·standard met·standard met–site not in the yearbook●standard not met
    Nutrients and nitrogen
    total phosphorus·standard met●standard not met–site not in the yearbook●standard not met
    nitrites·standard met●standard not met–site not in the yearbook·standard met
    Salts, pH and minerals
    pH●standard not met·standard met–site not in the yearbook·standard met
    calcium·standard met●standard not met–site not in the yearbook·standard met
    PAHs: 5 substances (not counted in the score)
    Indicator2022202320242025
    PAHs (combustion and deposition)
    benzo(a)pyrene●standard not met●standard not met–site not in the yearbook●standard not met
    benzo(b)fluoranthene·standard met·standard met–site not in the yearbook●standard not met
    benzo(k)fluoranthene·standard met·standard met–site not in the yearbook●standard not met
    fluoranthene·standard met·standard met–site not in the yearbook●standard not met
    perylene·standard met·standard met–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.

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

  19. ČechynceNitra, river km 47.81 indicator in 2025
    Indicator2022202320242025
    Oxygen and organic matter
    BOD₅ (biochemical oxygen demand)·standard met●standard not met–site not in the yearbook·standard met
    Nutrients and nitrogen
    total phosphorus●standard not met●standard not met–site not in the yearbook●standard not met
    nitrites●standard not met●standard not met–site not in the yearbook·standard met
    Salts, pH and minerals
    pH●standard not met·standard met–site not in the yearbook·standard met

    Nearest site for the fishing districts: Nitra č. 2, Nitra č. 3, Štrkovisko Čechynce

  20. JelenecJelenský potok, river km 3.57 indicators in 2024
    Indicator2022202320242025
    Oxygen and organic matter
    dissolved oxygen·standard met–site not in the yearbook●standard not met–site not in the yearbook
    Nutrients and nitrogen
    total phosphorus●standard not met–site not in the yearbook●standard not met–site not in the yearbook
    ammonium·standard met–site not in the yearbook●standard not met–site not in the yearbook
    total nitrogen·standard met–site not in the yearbook●standard not met–site not in the yearbook
    Harmful organic substances
    octylphenol●standard not met–site not in the yearbook·standard met–site not in the yearbook
    Salts, pH and minerals
    pH●standard not met–site not in the yearbook·standard met–site not in the yearbook
    PAHs: 3 substances (not counted in the score)
    Indicator2022202320242025
    PAHs (combustion and deposition)
    benzo(a)pyrene●standard not met–site not in the yearbook●standard not met–site not in the yearbook
    fluoranthene●standard not met–site not in the yearbook●standard not met–site not in the yearbook
    benzo(ghi)perylene·standard met–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: VN Jelenec II.

  • 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

  • Žitava kanál č. 1site Hul · standard not met in 4 of 4 years · nitrates in the groundwater nearby 18.5 mg/l7 indicators
  • Žitava č. 1site Hul · standard not met in 4 of 4 years · nitrates in the groundwater nearby 0.5 mg/l7 indicators
  • Žitava č. 2site Hul · standard not met in 4 of 4 years · nitrates in the groundwater nearby 0.5 mg/l7 indicators
  • Žitava č. 3site Hul · standard not met in 4 of 4 years · nitrates in the groundwater nearby 18.5 mg/l7 indicators
  • VN Jelenec II.site Jelenec · standard not met in 2 of 4 years · nitrates in the groundwater nearby 0.5 mg/l7 indicators
  • Nitra č. 5asite Chalmová · standard not met in 4 of 4 years · nitrates in the groundwater nearby 10.7 mg/l5 indicators
  • Nitra č. 6asite Chalmová · standard not met in 4 of 4 years · nitrates in the groundwater nearby 0.5 mg/l5 indicators
  • Nitrica č. 3site Valaská Belá · standard not met in 1 of 4 years · nitrates in the groundwater nearby 16.7 mg/l5 indicators
  • Nitrica č. 4site Valaská Belá · standard not met in 1 of 4 years · nitrates in the groundwater nearby 3.2 mg/l5 indicators
  • Tužinasite Tužina, above, water-supply watercourse · standard not met in 1 of 4 years · nitrates in the groundwater nearby 4.6 mg/l5 indicators
  • Nitra č. 1site Nové Zámky, Berek part · standard not met in 2 of 4 years · nitrates in the groundwater nearby 1.0 mg/l4 indicators
  • Bebrava č. 1site Podlužany · standard not met in 2 of 4 years · nitrates in the groundwater nearby 10.7 mg/l3 indicators
  • Bebrava č. 2site Podlužany · standard not met in 2 of 4 years · nitrates in the groundwater nearby 10.7 mg/l3 indicators
  • Bebrava č. 3site Podlužany · standard not met in 2 of 4 years · nitrates in the groundwater nearby 7.5 mg/l3 indicators
  • VN Klátová Nová Vessite Klátova Nová Ves · standard not met in 2 of 4 years · nitrates in the groundwater nearby 32.7 mg/l3 indicators
  • Vyčoma č. 1site Klátova Nová Ves · standard not met in 2 of 4 years · nitrates in the groundwater nearby 3.9 mg/l3 indicators
  • Nitra č. 6bsite Nedožery · standard not met in 1 of 4 years · nitrates in the groundwater nearby 0.5 mg/l3 indicators
  • Nitra č. 7site Nedožery · standard not met in 1 of 4 years · nitrates in the groundwater nearby 3.2 mg/l3 indicators
  • Chotinasite Nemečky, above · standard not met in 1 of 4 years · nitrates in the groundwater nearby 15.2 mg/l2 indicators
  • Chrenovkasite Bánov, near · standard not met in 1 of 4 years · nitrates in the groundwater nearby 31.8 mg/l2 indicators
  • Hostiansky potoksite Zlaté Moravce · standard not met in 1 of 4 years · nitrates in the groundwater nearby 13.7 mg/l2 indicators
  • Levešsite Topoľčianky, above · standard not met in 1 of 4 years · nitrates in the groundwater nearby 9.8 mg/l2 indicators
  • OR Bánovsite Bánov, near · standard not met in 1 of 4 years · nitrates in the groundwater nearby 31.8 mg/l2 indicators
  • Osliansky potok č. 1site Osliansky potok, mouth · standard not met in 1 of 4 years · nitrates in the groundwater nearby 6.7 mg/l2 indicators
  • Radiša č. 1site Horné Naštice · standard not met in 1 of 4 years · nitrates in the groundwater nearby 0.5 mg/l2 indicators
  • Svinica č. 1site Bánovce nad Bebravou, Dolné Ozorovce · standard not met in 1 of 4 years · nitrates in the groundwater nearby 9.3 mg/l2 indicators
  • Svinica č. 2site Bánovce nad Bebravou, Dolné Ozorovce · standard not met in 1 of 4 years · nitrates in the groundwater nearby 9.3 mg/l2 indicators
  • VN Nemečkysite Nemečky, above · standard not met in 1 of 4 years · nitrates in the groundwater nearby 15.2 mg/l2 indicators
  • VN Slepčanysite Slepčany · standard not met in 1 of 4 years · nitrates in the groundwater nearby 8.8 mg/l2 indicators
  • VN Topolčiankysite Topoľčianky, above · standard not met in 1 of 4 years · nitrates in the groundwater nearby 9.8 mg/l2 indicators
  • Žitava č. 4site Obyce, above · standard not met in 1 of 4 years · nitrates in the groundwater nearby 13.7 mg/l2 indicators
  • Žitava č. 5site Obyce, above · standard not met in 1 of 4 years · nitrates in the groundwater nearby 5.7 mg/l2 indicators
  • Handlovka č. 1site Koš · standard not met in 4 of 4 years · nitrates in the groundwater nearby 0.5 mg/l1 indicator
  • Nitrica č. 1asite Partizánske · standard not met in 4 of 4 years · nitrates in the groundwater nearby 10.7 mg/l1 indicator
  • Nitrica č. 1bsite Partizánske · standard not met in 4 of 4 years · nitrates in the groundwater nearby 10.7 mg/l1 indicator
  • Nitrica č. 1csite Partizánske · standard not met in 4 of 4 years · nitrates in the groundwater nearby 10.7 mg/l1 indicator
  • Nitrica č. 1dsite Partizánske · standard not met in 4 of 4 years · nitrates in the groundwater nearby 5.4 mg/l1 indicator
  • Nitrica č. 2site Partizánske · standard not met in 4 of 4 years · nitrates in the groundwater nearby 5.4 mg/l1 indicator
  • Nitra č. 2site Čechynce · standard not met in 3 of 4 years · nitrates in the groundwater nearby 0.5 mg/l1 indicator
  • Nitra č. 3site Čechynce · standard not met in 3 of 4 years · nitrates in the groundwater nearby 0.5 mg/l1 indicator

Showing 40 of 51 fishing districts, worst first.

What most often fails

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

  1. total phosphorusNutrients and nitrogen17
  2. benzo(a)pyrenePAHs (combustion and deposition)15
  3. BOD₅ (biochemical oxygen demand)Oxygen and organic matter11
  4. conductivitySalts, pH and minerals10
  5. fluoranthenePAHs (combustion and deposition)9
  6. COD (chemical oxygen demand)Oxygen and organic matter8
  7. nitratesNutrients and nitrogen8
  8. total nitrogenNutrients and nitrogen7
  9. benzo(b)fluoranthenePAHs (combustion and deposition)6
  10. perylenePAHs (combustion and deposition)6
  11. calciumSalts, pH and minerals5
  12. benzo(k)fluoranthenePAHs (combustion and deposition)4
  • 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.