KAZALCI OKOLJA

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Key message
Neutral

Slovenian groundwater bodies most polluted with nitrates are those with intergranular (alluvium) aquifers, particularly in north-eastern Slovenia. Groundwater in karst and fractured aquifers is less burdened with nitrates due to geographical conditions, low population density and less agricultural land. In the period 1998–2019, the average annual levels of nitrates in water bodies in the Sava valley, Ljubljansko barje, Savinja, Drava and Mura basins show a statistically significant downward trend. In other water bodies, nitrate levels are not statistically significant.


This indicator shows the concentration of nitrates in groundwater samples. Mean annual values for individual measuring sites, water bodies in Slovenia and Europe, were calculated.

Nitrates can be naturally present in groundwater. Natural background concentrations of nitrates depend on geological properties of aquifers – in Slovenia, they are below 10 mg NO3/l. Increased concentrations of nitrates in groundwater are a result of human activities, agriculture in particular. Nitrates can also appear in groundwater as a consequence of improper urban wastewater management. In Slovenia, groundwater represents the main source of drinking water.


Charts

Figure VD05-1: Average annual values ​​of nitrate in groundwater samples at the sampling points of the Slovenian national monitoring in 2019
Sources: 

Standardised Database for Water Quality Monitoring, Slovenian Environmental Agency, 2020

Figure VD05-2: The average value of nitrate levels in Europe and in Slovenia and Slovenian groundwater bodies with predominantly intergranular (alluvial) and karst/fractured aquifers
Show data
Slovenija - alluvial aquifers[mg/l]Slovenia - karst-fractured aquifers[mg/l]Slovenia - average[mg/l]Europa - average[mg/l]
200440.567.4815.3620.04
200540.297.3915.2319.72
200638.597.4114.8419.50
200731.757.3313.1519.27
200832.776.7812.9719.20
200932.876.5812.8419.12
201031.955.5011.8019.28
201131.206.6012.5019.28
201230.205.3611.2819.28
201332.305.2711.7019.28
201432.215.2711.6919.28
201531.055.7811.8019.28
201625.355.5011.4419.28
201731.735.9012.0519.28
201831.955.6111.8819.28
201930.115.7811.5719.28
Figure VD05-3: Average annual nitrate levels in groundwater of the more polluted water bodies
Show data
1001 Savska kotlina in Ljubljansko barje[mg/l]1002 Savinjska kotlina[mg/l]1003 Krška kotlina[mg/l]3012 Dravska kotlina[mg/l]4016 Murska kotlina[mg/l]quality standard[mg/l] [ ]
199823.3950.0121.8445.1047.63501
199922.8043.7823.8048.3739.7550
200021.6447.2120.3945.4447.3450
200121.9455.4925.6846.4650
200220.6843.8832.9639.7034.4350
200320.7050.4522.3440.2939.8650
200420.9065.0329.4449.4537.9850
200522.9057.8324.7654.0141.9950
200622.7045.3726.9453.2544.6750
200718.3847.2921.1039.1232.8850
200819.5748.6523.1640.2832.2050
200920.6344.8324.1942.1332.5750
201019.2142.5224.0542.1831.7850
201119.2043.2021.603932.9050
201218.2346.9123.6635.5626.6550
201318.9340.2428.6742.3131.3650
201418.8043.9824.5240.0033.7350
201517.9644.6623.6440.2728.7350
201616.7542.0224.5338.5130.3250
201716.8349.8524.1339.0928.7550
201818.7844.4125.7139.6631.1950
201917.4647.7521.8536.1127.3750
Figure VD05-4: The declining trend of the nitrate concentration in water bodies Sava, Mura, Drava and Savinja basin in the period 1998-2019
Sources: 

Enotna zbirka podatkov monitoringa kakovosti voda (2020)

Figure VD05-5: Structure of agricultural land use in 2018 and groundwater quality by water bodies in 2019
Sources: 

Environmental Agency of the Republic of Slovenia, 2020. Agricultural Institute of Slovenia (2020)

Figure VD05-6: Share of agricultural area in the surface of ground water bodies in Slovenia in 2018 (%)
Sources: 

Ministry of Agriculture, Forestry and Food (2020)

Chart note: 

Red coloured bars denote ground water bodies with poor chemical state because the nitrate concentration limit is exceeded.

Figure VD05-7: Total nitrogen emissions from municipal wastewater treatment plants (t / year)
Sources: 

Waste Water Treatment Plants Database, Environmental Agency of the Republic of Slovenia (2020)

Show data

Indirect outflow into groundwater[t/year]

Outflow into surface waters[t/year]

2010

5.90

1993.30

2011

6.60

2011.40

2012

3.40

1710.40

2013

2.40

1707.10

2014

4.50

1634

2015

5.90

1502

2016

9.70

1321.40

2017

9.90

1315.50

2018

12

1388.60

2019

12.80

1283.10


Goals

  • To improve the state of the water environment
  • To reduce emissions from dispersed sources (intensive agriculture, dispersed settlement without wastewater treatment)
  • To achieve a favourable state of groundwater by 2015
  • To reduce concentrations of nitrates in overburdened groundwater below 50 mg NO3/l and to reverse the trends of increasing nitrate concentrations

 



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