250
I. Jamorska
11.4.3 Lowlands Zone
In the western part of the lowland zone, in the so-called subregion of the Wartanian
lowland, groundwater occurs in the Quaternary, Palaeogene and Neogene, Cretaceous and Jurassic formations. The lowest quality class of groundwater can be
ascribed to the Quaternary aquifer (observation wells number II/527/1, II/1424/1).
The reason for this is the presence of excessive concentrations of Fe, Mn and NH 4 .
This type of water occurs in central parts of valleys, within the range of flood terraces,
where the Holocene formations contain young reactive organic matter [18–21]. The
hydrogeochemical types of this groundwater are Cl–HCO 3 –Na (observation well
number II/527/1) or HCO 3 –SO 4 –Cl–Ca (observation well number II/1424/1). The
best quality water can be found in shallow reservoirs created by fluvioglacial formations (observation well number II/1325/1), where the groundwater type HCO 3 -Ca of
the quality class II prevails. The chemical properties of the Palaeogene and Neogene
aquifer are diversified due to the inflow of saline water from the Mesozoic basement
supplemented by the percolation of water from the Quaternary aquifer. As a consequence of this, both good quality water of the HCO 3 –Ca type and multi-ionic water
of the Cl–HCO 3 –Na type with excessive concentrations of Cl, Na, NH4 and Fe ions
occur here (observation well II/1144/1).
Groundwater of the Cretaceous aquifer is characterised by its very good quality,
and locally they attain quality class I (monitoring point number I/273/1). On account
of carbonate environment of this type of groundwater, the concentrations of Fe and
Mn are on a very low level. The groundwater of the Jurassic aquifer, due to locally
direct contact with Quaternary and Palaeogene and Neogene formations, has slightly
lower quality and it belongs to quality class II.
In the eastern part of the lowland, in the subregion of the middle Vistula River,
apart from the typical groundwater of the HCO 3 –Ca and HCO 3 –Ca–Mg types, multiionic waters, the chemical composition of which has been shaped by both natural
processes and anthropogenic pollution can be found. In the central part of the area,
in the isolated groundwater of the Paleogene and Neogene aquifer, among the main
ions, the prevalence of the Na and Cl ions can be recorded. In the so-called transition zone groundwater of the HCO 3 –Ca–Na, HCO 3 –Cl–Na or HCO 3 –Cl–Na-Ca
types (observation well number I/40/2). Long-term observations indicate considerable sustainability of their chemical composition, constant and unchanged even in
the zones of intensive consumption [22, 23]. The groundwater of the Jurassic aquifer
in the eastern part of the lowlands constitutes good quality water of the HCO 3 –Ca
and HCO 3 –Ca–Mg types.
11.4.4 Uplands Zone
The chemical composition of groundwater in the western part of the upland area (the
subregion of the middle upland Vistula River) is extremely diverse. The Uplands
I. Jamorska
11.4.3 Lowlands Zone
In the western part of the lowland zone, in the so-called subregion of the Wartanian
lowland, groundwater occurs in the Quaternary, Palaeogene and Neogene, Cretaceous and Jurassic formations. The lowest quality class of groundwater can be
ascribed to the Quaternary aquifer (observation wells number II/527/1, II/1424/1).
The reason for this is the presence of excessive concentrations of Fe, Mn and NH 4 .
This type of water occurs in central parts of valleys, within the range of flood terraces,
where the Holocene formations contain young reactive organic matter [18–21]. The
hydrogeochemical types of this groundwater are Cl–HCO 3 –Na (observation well
number II/527/1) or HCO 3 –SO 4 –Cl–Ca (observation well number II/1424/1). The
best quality water can be found in shallow reservoirs created by fluvioglacial formations (observation well number II/1325/1), where the groundwater type HCO 3 -Ca of
the quality class II prevails. The chemical properties of the Palaeogene and Neogene
aquifer are diversified due to the inflow of saline water from the Mesozoic basement
supplemented by the percolation of water from the Quaternary aquifer. As a consequence of this, both good quality water of the HCO 3 –Ca type and multi-ionic water
of the Cl–HCO 3 –Na type with excessive concentrations of Cl, Na, NH4 and Fe ions
occur here (observation well II/1144/1).
Groundwater of the Cretaceous aquifer is characterised by its very good quality,
and locally they attain quality class I (monitoring point number I/273/1). On account
of carbonate environment of this type of groundwater, the concentrations of Fe and
Mn are on a very low level. The groundwater of the Jurassic aquifer, due to locally
direct contact with Quaternary and Palaeogene and Neogene formations, has slightly
lower quality and it belongs to quality class II.
In the eastern part of the lowland, in the subregion of the middle Vistula River,
apart from the typical groundwater of the HCO 3 –Ca and HCO 3 –Ca–Mg types, multiionic waters, the chemical composition of which has been shaped by both natural
processes and anthropogenic pollution can be found. In the central part of the area,
in the isolated groundwater of the Paleogene and Neogene aquifer, among the main
ions, the prevalence of the Na and Cl ions can be recorded. In the so-called transition zone groundwater of the HCO 3 –Ca–Na, HCO 3 –Cl–Na or HCO 3 –Cl–Na-Ca
types (observation well number I/40/2). Long-term observations indicate considerable sustainability of their chemical composition, constant and unchanged even in
the zones of intensive consumption [22, 23]. The groundwater of the Jurassic aquifer
in the eastern part of the lowlands constitutes good quality water of the HCO 3 –Ca
and HCO 3 –Ca–Mg types.
11.4.4 Uplands Zone
The chemical composition of groundwater in the western part of the upland area (the
subregion of the middle upland Vistula River) is extremely diverse. The Uplands