River and Lake Water Quality
Content
Nutrient and Heavy Metals Emission

The emissions of nutrient and heavy metals from balanced point-sources of pollution (municipal waste water and industry) into surface water:

Balanced sources of pollution - the point sources of pollution that satisfy at least one of these conditions:

annual discharged quantity of waste water > 15 000 m3 per year
BOD5 >3 tonnes per year
CODCr> 6 tonnes per year
Solids (TS) > 5 tonnes per year
Soluble inorganic salts > 10 tonnes per year
Extractable non-polar substances (ENP) > 0.5 tonnes per year or ENP > 5 mg per l.

Nutrient emission from balanced point sources of pollution into surface water (1995 - 1997)
 
River basin
Year
Nutrient emission (in tonnes per year)
   
N-NH4+
N-NO3
N
P
Dunaj Basin 
1995
796.4
-
-
-
 
1996
535.1
-
-
       0.052
 
1997
533.9
-
  128.5
262.2
Váh Basin 
1995
3 042.5
-
-
-
 
1996
3 221.3
-
-
-
 
1997
2 966.3
-
-
-
Hron Basin 
1995
457.9
250.6
1047.6
 82.7
 
1996
499.3
164.3
1072.3
 93.9
 
1997
487.1
236.1
1074.0
127.8
Bodrog and Hornád Basin 
1995
-
-
-
-
 
1996
1079.1
-
-
126.4
 
1997
259.3
0.781
-
  90.4
 Source: SHMÚ

Regarding the presence of nutrients in waste water only the amounts of ammonium-nitrate were analysed. Amounts being discharged into different catchment areas on the territory of Slovakia are shown in the following chart.

Discharged amount of N-NH4+ in waste waters in the following catchment areas (in tonnes per year)

Source: SHMU

In 1997, total discharged amount of N-NH4+ in waste waters decreased in comparison to 1996 from 5 250.9 tonnes per year to 5 017.8 tonnes per year.

Heavy metal emissions from balanced point sources of pollution into surface water (1995 - 1997)
 
River Basins
Year
Heavy metal emissions (in tonnes per year)
   
Hg
Cd
Pb
Cu
Cr
Co
Ni
Zn
Al
Dunaj Basin 
1995
-
-
-
0.035
0.040
-
0.050
24.029
-
 
1996
-
-
-
0.035
0.120
-
0.004
14.883
-
 
1997
0.010
-
0.004
1.741
0.670
0.132
0.190
22.058
-
Váh Basin 
1995
-
-
0.001
0.010
1.320
-
0.620
 0.950
-
 
1996
-
-
0.002
0.005
0.110
-
0.560
 0.539
-
 
1997
-
-
0.008
0.006
0.030
-
0.342
 0.313
-
Hron Basin 
1995
-
-
-
0.070
-
-
-
-
  38.75
 
1996
-
-
-
-
-
-
-
-
106.83
 
1997
-
-
-
-
-
-
-
-
  17.31
Bodrog and Hornád Basin 
1995
-
-
-
-
-
-
-
-
-
 
1996
-
-
-
-
-
-
-
-
-
 
1997
-
-
-
-
-
-
-
-
-
   Source: SHMÚ