6 Quality Assessment of Water Resources of River in Poland
139
6.4.1 Assessment of Status of Physico-Chemical Elements
In physico-chemical terms, river water quality is classified according to the standards
defining the threshold values for classes I and II. Due to the general assumption of
the WFD, that the ecological status of surface waters is considered appropriate if
it corresponds to two states: high and good, no standards are set for the other three
classes of physico-chemical indicators. The standards for physico-chemical quality
class I and II waters also takes into account rivers’ abiotic types. The threshold
values for physico-chemical indicators of river water quality are given in Table 6.5.
According to WFD rules, the state of physico-chemical elements is determined by
the least favourable indicator.
In physico-chemical terms, water quality is highest in the catchments and
subcatchments of the Baltic Sea coast, Szczecin Lagoon, Vistula Lagoon (including
the Pregola) and Neman (Fig. 6.11). Over 74% of water bodies tested in 2010–
2015 were assessed as meeting the standards for cleanliness classes I and II. In the
Vistula catchment, 66% of surface water bodies met WFD requirements. The lowest
percentage of surface water bodies to belong to cleanliness classes I and II was in
the Oder catchment, at 56%. The most frequently exceeded standards concerned
indicators of biogenic pollution, and, to a lesser extent, organic.
The river water bodies of the top water quality class I occur mainly in the
catchments of mountain and foothill rivers of the Carpathians (the Soła, Skawa,
Raba, Dunajec, Wisłoka) and the Sudetes (the Nysa Kłodzka, Bóbr, Nysa Łu˙ zycka,
Table 6.5 Threshold values
of selected of water quality in
rivers designated as discrete
Surface Water Bodies
(according to the Regulation
of the Minister of the
Environment 2014)
Indicator
Unit
Water quality
indicator threshold
Class I
Class II
BOD 5
mgO 2 /L
≤3
≤6
TOC
mgC/L
≤10
≤15
TOC 1
mgC/L
≤15
≤20
SEC
µS/cm
≤1,000 ≤1,500
Hardness 2
mgCaCO 3 /L ≤200
≤300
Hardness 3
mgCaCO 3 /L ≤300
≤500
Ammonium
mgN-NH 4 /L ≤0.78
≤1.56
Total Kjeldahl Nitrogen mgN/L
≤1.00
≤2.00
Nitrate as nitrogen
mgN-NO 3 /L ≤2.20
≤5.00
Total nitrogen
mgN/L
≤5.00
≤10.00
Phosphates
mgPO 4 /L
≤0.20
≤0.31
Total phosphorus
mgP/L
≤0.20
≤0.40
1 for type rivers 23 and 24
2 for type rivers: 1.3–5, 8,10
3 for type rivers 2, 6, 7, 9, 12, 14–26
139
6.4.1 Assessment of Status of Physico-Chemical Elements
In physico-chemical terms, river water quality is classified according to the standards
defining the threshold values for classes I and II. Due to the general assumption of
the WFD, that the ecological status of surface waters is considered appropriate if
it corresponds to two states: high and good, no standards are set for the other three
classes of physico-chemical indicators. The standards for physico-chemical quality
class I and II waters also takes into account rivers’ abiotic types. The threshold
values for physico-chemical indicators of river water quality are given in Table 6.5.
According to WFD rules, the state of physico-chemical elements is determined by
the least favourable indicator.
In physico-chemical terms, water quality is highest in the catchments and
subcatchments of the Baltic Sea coast, Szczecin Lagoon, Vistula Lagoon (including
the Pregola) and Neman (Fig. 6.11). Over 74% of water bodies tested in 2010–
2015 were assessed as meeting the standards for cleanliness classes I and II. In the
Vistula catchment, 66% of surface water bodies met WFD requirements. The lowest
percentage of surface water bodies to belong to cleanliness classes I and II was in
the Oder catchment, at 56%. The most frequently exceeded standards concerned
indicators of biogenic pollution, and, to a lesser extent, organic.
The river water bodies of the top water quality class I occur mainly in the
catchments of mountain and foothill rivers of the Carpathians (the Soła, Skawa,
Raba, Dunajec, Wisłoka) and the Sudetes (the Nysa Kłodzka, Bóbr, Nysa Łu˙ zycka,
Table 6.5 Threshold values
of selected of water quality in
rivers designated as discrete
Surface Water Bodies
(according to the Regulation
of the Minister of the
Environment 2014)
Indicator
Unit
Water quality
indicator threshold
Class I
Class II
BOD 5
mgO 2 /L
≤3
≤6
TOC
mgC/L
≤10
≤15
TOC 1
mgC/L
≤15
≤20
SEC
µS/cm
≤1,000 ≤1,500
Hardness 2
mgCaCO 3 /L ≤200
≤300
Hardness 3
mgCaCO 3 /L ≤300
≤500
Ammonium
mgN-NH 4 /L ≤0.78
≤1.56
Total Kjeldahl Nitrogen mgN/L
≤1.00
≤2.00
Nitrate as nitrogen
mgN-NO 3 /L ≤2.20
≤5.00
Total nitrogen
mgN/L
≤5.00
≤10.00
Phosphates
mgPO 4 /L
≤0.20
≤0.31
Total phosphorus
mgP/L
≤0.20
≤0.40
1 for type rivers 23 and 24
2 for type rivers: 1.3–5, 8,10
3 for type rivers 2, 6, 7, 9, 12, 14–26