Surface water

Surface water pollution

Sites in the 2025 yearbook: 363
Failed the standard (81%): 294
Counted in the score: 203
River basin: 14

Surface water

SHMÚ state monitoring, 2022 to 2025

Surface water, 2025SHMÚ state monitoring sites on watercourses and reservoirs
- 69sites met all standards
- 91fails the standard only in indicators outside the score (mainly PAHs, salts, minerals)
- 203fails the standard for oxygen, nutrients, metals or harmful substances

Every year SHMÚ assesses water quality at hundreds of sites on watercourses and reservoirs. The yearbook lists the sites and indicators that failed the standard. In 2025 it was 294 of 363 sites. Most often these are PAHs from combustion and minerals, which matter less to fish, and nutrients and oxygen, which harm fish directly. Each row below can be expanded into an “indicator × year” matrix.

Year-by-year trend

Share of yearbook sites that failed the standard

2022331 of 38287%
2023313 of 37783%
2024322 of 42775%
2025294 of 36381%

The number of sites in the yearbook changes slightly between years, so shares are compared.

River basins

From most to least polluted; click for details

Map of fishing districts by pollution

Each fishing district by its nearest SHMÚ monitoring site

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

Region

River basin

District and local SRZ organization

1445fishing districts

Pick a category to narrow the selection. Next to each option you can see how many fishing districts remain.

Map color

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Move the map with two fingers. In full-screen mode one finger is enough.

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

The first 30 by number of failed indicators and years; click to expand the history

Zemplínske HradišteTrnávka, river km 7.5 · Bodrog basin5 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).
Devínska Nová Ves, belowMláka, river km 0.5 · Morava basin7 indicators in 2025
Indicator2022202320242025
Nutrients and nitrogen
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 not met●standard not met·standard met●standard not met
Harmful organic substances
AOX (adsorbable organic halogens)●standard not met●standard not met●standard not met●standard not met
octylphenol·standard met●standard not met·standard met·standard met
Salts, pH and minerals
aluminium·standard met●standard not met●standard not met●standard not met
calcium●standard not met●standard not met●standard not met·standard met
pH·standard met●standard not met·standard met·standard met
Biology and bacteria
saprobic index of biosestone●standard not met●standard not met●standard not met●standard not met
phytoplankton abundance·standard met●standard not met·standard met·standard met
chlorophyll a·standard met●standard not met·standard met·standard met
culturable microorganisms (22 °C)·standard met●standard not met·standard met·standard met
intestinal enterococci·standard met●standard not 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 not met●standard not met
benzo(ghi)perylene·standard met●standard not met·standard met·standard met
fluoranthene·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.
Adamov, KopčanyUnínsky potok, river km 2.7 · Morava basin8 indicators in 2025
Indicator2022202320242025
Oxygen and organic matter
COD (chemical oxygen demand)·standard met●standard not met●standard not met·standard met
dissolved oxygen·standard met·standard met·standard met●standard not met
Nutrients and nitrogen
nitrites·standard met●standard not met●standard not met●standard not met
total phosphorus·standard met●standard not met●standard not met●standard not met
ammonium·standard met●standard not met·standard met●standard not met
nitrates·standard met●standard not met●standard not met·standard met
total nitrogen·standard met●standard not met·standard met●standard not met
Harmful organic substances
AOX (adsorbable organic halogens)·standard met●standard not met●standard not met●standard not met
chlorpyrifos●standard not met·standard met·standard met·standard met
Salts, pH and minerals
conductivity·standard met●standard not met●standard not met●standard not met
calcium·standard met●standard not met●standard not met●standard not met
pH·standard met●standard not met·standard met·standard met
Biology and bacteria
chlorophyll a·standard met·standard met●standard not met·standard met
PAHs: 1 substance (not counted in the score)
Indicator2022202320242025
PAHs (combustion and deposition)
benzo(a)pyrene·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.
Nearest site for the fishing districts: Štrkovisko Unín
Topoľčny, road bridge to KrušovceBedziansky P., river km 1.4 · Nitra basin7 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).
PršaSuchá, river km 3.1 · Ipeľ basin4 indicators in 2025
Indicator2022202320242025
Oxygen and organic matter
total organic carbon●standard not met●standard not met●standard not met·standard met
dissolved oxygen●standard not met·standard met●standard not met●standard not 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
ammonium●standard not met·standard met·standard met·standard met
Metals
nickel●standard not met·standard 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
calcium●standard not met●standard not met●standard not 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 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).
WWTP Jablonka, belowBlack Orava, river km 3.2 · Váh basin3 indicators in 2025
Indicator2022202320242025
Oxygen and organic matter
total organic carbon·standard met●standard not met●standard not met●standard not met
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
Harmful organic substances
AOX (adsorbable organic halogens)●standard not met●standard not met·standard met●standard not met
Biology and bacteria
saprobic index of biosestone●standard not met●standard not met●standard not met·standard met
PAHs: 1 substance (not counted in the score)
Indicator2022202320242025
PAHs (combustion and deposition)
benzo(a)pyrene●standard not met●standard not 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).
Kyjov, mouthKyjov, river km 0.6 · Bodrog basin8 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.
PohanskoDyje, river km 17.0 · Morava basin9 indicators in 2025
Indicator2022202320242025
Oxygen and organic matter
COD (chemical oxygen demand)·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
total phosphorus●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
Salts, pH and minerals
pH●standard not met●standard not met●standard not met●standard not met
manganese·standard met●standard not met·standard met·standard met
Biology and bacteria
phytoplankton abundance●standard not met●standard not met●standard not met●standard not met
chlorophyll a●standard not met·standard met●standard not met●standard not 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 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.
Poľný Kesov, below (above the Rastislavice Reservoir)Cabajský potok, river km 10.8 · Nitra basin7 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).
ZohorMalina, river km 4.2 · Morava basin4 indicators in 2025
Indicator2022202320242025
Oxygen and organic matter
dissolved oxygen●standard not 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
total phosphorus●standard not met●standard not met●standard not 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 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 not met●standard not 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.
The location of the site is only approximate (based on the water body).
Široká landfill, belowBP Oravy (Homôlka), river km 0.2 · Váh basin9 indicators in 2025
Indicator2022202320242025
Oxygen and organic matter
COD (chemical oxygen demand)●standard not met●standard not met·standard met·standard met
Nutrients and nitrogen
ammonium●standard not met·standard met●standard not met●standard not met
total phosphorus●standard not met●standard not met·standard met●standard not met
total nitrogen·standard met·standard met·standard met●standard not met
Metals
arsenic●standard not met●standard not met●standard not met●standard not met
chromium●standard not met·standard met·standard met●standard not met
Harmful organic substances
AOX (adsorbable organic halogens)·standard met·standard met·standard met●standard not met
total cyanides·standard met·standard met●standard not met·standard met
Salts, pH and minerals
pH●standard not met●standard not met●standard not met●standard not met
conductivity●standard not met●standard not met●standard not met●standard not met
dissolved solids (105 °C)●standard not met●standard not met·standard met●standard not met
chlorides●standard not met·standard met·standard met·standard met
fluorides●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 met●standard not met·standard met
benzo(ghi)perylene·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.
HolíčKopčiansky kanál, river km 3.0 · Morava basin10 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 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 not met·standard met·standard met
aluminium·standard met●standard not met·standard met·standard met
Biology and bacteria
chlorophyll a●standard not met●standard not met●standard not met●standard not met
saprobic index of biosestone●standard not met●standard not met●standard not met●standard not met
phytoplankton abundance●standard not 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(ghi)perylene●standard not met●standard not met●standard not met·standard met
benzo(b)fluoranthene·standard met·standard met·standard met●standard not 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.
Slovenské Nové MestoRoňava, river km 2.2 · Bodrog basin8 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).
HulŽitava, river km 3.5 · Nitra basin7 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).
Kremnica, belowKremnický potok, river km 12.6 · Hron basin8 indicators in 2025
Indicator2022202320242025
Oxygen and organic matter
COD (chemical oxygen demand)●standard not met–site not in the yearbook·standard met●standard not met
BOD₅ (biochemical oxygen demand)·standard met–site not in the yearbook·standard met●standard not met
Nutrients and nitrogen
ammonium●standard not met–site not in the yearbook·standard met●standard not met
total phosphorus●standard not met–site not in the yearbook·standard met●standard not met
nitrites·standard met–site not in the yearbook·standard met●standard not met
Metals
copper·standard met–site not in the yearbook●standard not met·standard met
lead·standard met–site not in the yearbook●standard not met·standard met
zinc·standard met–site not in the yearbook●standard not met·standard met
Harmful organic substances
AOX (adsorbable organic halogens)·standard met–site not in the yearbook·standard met●standard not met
total cyanides·standard met–site not in the yearbook●standard not met·standard met
Salts, pH and minerals
S (according to the SHMÚ yearbook)·standard met–site not in the yearbook·standard met●standard not met
aluminium·standard met–site not in the yearbook·standard met●standard not met
Nearest site for the fishing districts: Kremnický potok
Morava, road Devínska Nová Ves – VysokáMorava, river km 14.7 · Morava basin9 indicators in 2025
Indicator2022202320242025
Nutrients and nitrogen
nitrites●standard not met●standard not met●standard not met●standard not met
total phosphorus●standard not met●standard not met·standard met·standard met
Harmful organic substances
AOX (adsorbable organic halogens)·standard met●standard not met●standard not met●standard not met
Salts, pH and minerals
pH●standard not met●standard not met●standard not met●standard not met
aluminium●standard not met●standard not met·standard met●standard not met
Biology and bacteria
phytoplankton abundance●standard not met●standard not met●standard not met●standard not met
chlorophyll a●standard not met●standard not met●standard not met●standard not met
saprobic index of biosestone·standard met●standard not met·standard met●standard not 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: Morava č. 1, Morava č. 2
The location of the site is only approximate (based on the water body).
Šárd – Horné SalibyŠárd, river km 1.8 · Váh basin7 indicators in 2025
Indicator2022202320242025
Oxygen and organic matter
dissolved oxygen●standard not met●standard not met–site not in the yearbook●standard not met
BOD₅ (biochemical oxygen demand)●standard not met·standard met–site not in the yearbook●standard not met
total organic carbon·standard met·standard met–site not in the yearbook●standard not met
Nutrients and nitrogen
total phosphorus●standard not met●standard not met–site not in the yearbook●standard not met
ammonium●standard not met·standard met–site not in the yearbook●standard not met
Salts, pH and minerals
conductivity●standard not met●standard not met–site not in the yearbook●standard not met
calcium●standard not met·standard met–site not in the yearbook·standard met
PAHs: 1 substance (not counted in the score)
Indicator2022202320242025
PAHs (combustion and deposition)
benzo(a)pyrene·standard met●standard not 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).
Zolná, mouthZolná, river km 0.5 · Hron basin12 indicators in 2025
Indicator2022202320242025
Oxygen and organic matter
total organic carbon·standard met●standard not met●standard not met·standard met
Nutrients and nitrogen
ammonium·standard met·standard met·standard met●standard not met
nitrites·standard met●standard not met·standard met·standard met
Metals
mercury·standard met·standard met·standard met●standard not met
Harmful organic substances
AOX (adsorbable organic halogens)·standard met·standard met●standard not met●standard not met
octylphenol·standard met●standard not met●standard not met·standard met
pentachlorophenol●standard not met·standard met·standard met·standard met
Biology and bacteria
saprobic index of biosestone·standard met●standard not met·standard met●standard not met
PAHs: 9 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 met●standard not met●standard not met●standard not met
anthracene·standard met·standard met·standard met●standard not met
benzo(b)fluoranthene·standard met·standard met·standard met●standard not met
benzo(ghi)perylene·standard met·standard met●standard not met·standard met
benzo(k)fluoranthene·standard met·standard met·standard met●standard not met
phenanthrene·standard met·standard met·standard met●standard not met
naphthalene·standard met·standard met·standard met●standard not 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.
Nearest site for the fishing districts: Zolná
The location of the site is only approximate (based on the water body).
HulLiska, river km 0.6 · Nitra basin8 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.
HidasnémetiHornád, river km 0.0 · Hornád basin5 indicators in 2025
Indicator2022202320242025
Oxygen and organic matter
COD (chemical oxygen demand)●standard not 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 met·standard met●standard not met·standard met
Harmful organic substances
AOX (adsorbable organic halogens)●standard not met●standard not met●standard not 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
thermotolerant coliform bacteria●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
saprobic index of biosestone·standard met●standard not met·standard met·standard met
Nearest site for the fishing districts: Hornád č. 1a
The location of the site is only approximate (based on the water body).
Veľký GrobStolicný P., river km 13.5 · Little Danube and Žitný ostrov basin3 indicators in 2025
Indicator2022202320242025
Oxygen and organic matter
COD (chemical oxygen demand)●standard not met●standard not met–site not in the yearbook●standard not met
BOD₅ (biochemical oxygen demand)●standard not 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
ammonium●standard not met·standard 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
Biology and bacteria
saprobic index of biosestone●standard not met●standard not met–site not in the yearbook·standard met
Nearest site for the fishing districts: Stoličný potok
TornyosnémetiSokoliansky P., river km 0.0 · Hornád basin12 indicators in 2025
Indicator2022202320242025
Nutrients and nitrogen
nitrites●standard not met●standard not met·standard met●standard not met
nitrates●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
total cyanides●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
fluorides●standard not met●standard not met●standard not met●standard not met
conductivity●standard not met●standard not met●standard not met●standard not 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
thermotolerant coliform bacteria●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
saprobic index of biosestone·standard met●standard not 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 not met
fluoranthene●standard not 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).
Moravský Svätý JánMorava, river km 67.3 · Morava basin10 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 not met●standard not met●standard not met
PFOS (perfluorooctane sulfonate)·standard met·standard met·standard met●standard not met
Salts, pH and minerals
aluminium●standard not met●standard not met●standard not met●standard not met
pH●standard not met●standard not met·standard met●standard not met
Biology and bacteria
phytoplankton abundance●standard not met●standard not met●standard not met●standard not met
chlorophyll a●standard not met●standard not met●standard not met●standard not met
saprobic index of biosestone·standard met●standard not met·standard met●standard not met
PAHs: 3 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
benzo(ghi)perylene●standard not met●standard not met●standard not met·standard met
fluoranthene·standard met●standard not 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: Morava č. 3, Morava č. 4, Morava č. 5
The location of the site is only approximate (based on the water body).
AndovceDlhý Kanál, river km 0.1 · Nitra basin6 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
BrehovOndava, river km 4.2 · Bodrog basin3 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).
BrodskéMorava, river km 79.0 · Morava basin9 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 not met●standard not met●standard not met
PFOS (perfluorooctane sulfonate)·standard met·standard met·standard met●standard not met
Salts, pH and minerals
aluminium●standard not met●standard not met●standard not met●standard not met
pH●standard not met●standard not met·standard met●standard not met
Biology and bacteria
phytoplankton abundance●standard not met·standard met●standard not met●standard not met
chlorophyll a●standard not met·standard met●standard not met●standard not met
saprobic index of biosestone·standard met●standard not met●standard not met·standard met
PAHs: 3 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(ghi)perylene·standard met●standard not 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.
Nearest site for the fishing districts: Morava č. 6, Morava č. 7a, Morava č. 7b
The location of the site is only approximate (based on the water body).
Poľný Kesov, aboveCabajský potok, river km 13.5 · Nitra basin8 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.
KútyMyjava, river km 3.0 · Morava basin5 indicators in 2025
Indicator2022202320242025
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 not met
Salts, pH and minerals
pH●standard not met●standard not met·standard met●standard not met
calcium●standard not met●standard not met●standard not met·standard met
PAHs: 1 substance (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
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).
Zemplínska Nová Ves – Stanča, road bridgeChlmec, river km 13.5 · Bodrog basin4 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).
VajnoryRaciansky p., river km 1.6 · Little Danube and Žitný ostrov basin4 indicators in 2025
Indicator2022202320242025
Oxygen and organic matter
COD (chemical oxygen demand)●standard not met●standard not met–site not in the yearbook·standard met
dissolved oxygen●standard not met·standard met–site not in the yearbook●standard not met
BOD₅ (biochemical oxygen demand)●standard not met·standard 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
ammonium●standard not met·standard met–site not in the yearbook·standard met
nitrites·standard met●standard not met–site not in the yearbook·standard met
Biology and bacteria
saprobic index of biosestone●standard not met●standard not met–site not in the yearbook●standard not met
PAHs: 1 substance (not counted in the score)
Indicator2022202320242025
PAHs (combustion and deposition)
benzo(a)pyrene·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.
Nearest site for the fishing districts: Štrkovisko Vajnory 1, Štrkovisko Vajnory 2

standard not met
no unmet standard
site not in the yearbook

What most often fails

Number of sites that failed the given indicator in 2025

benzo(a)pyrenePAHs (combustion and deposition)135
nitritesNutrients and nitrogen83
AOX (adsorbable organic halogens)Harmful organic substances71
total phosphorusNutrients and nitrogen66
pHSalts, pH and minerals51
fluoranthenePAHs (combustion and deposition)47
COD (chemical oxygen demand)Oxygen and organic matter43
conductivitySalts, pH and minerals32
total nitrogenNutrients and nitrogen31
nitratesNutrients and nitrogen28
dissolved oxygenOxygen and organic matter26
BOD₅ (biochemical oxygen demand)Oxygen and organic matter26
calciumSalts, pH and minerals24
ammoniumNutrients and nitrogen22
perylenePAHs (combustion and deposition)21
benzo(b)fluoranthenePAHs (combustion and deposition)18

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.