Chemical differentiation of water within groundwater table fluctuation area: Kampinos research field case study [Central Poland]

Researches were conducted within expertimental field Kampinos located within the protected zone surrounding Kampinos National Park but is considered to be the example of the anthropogenic impact on the quality of the groundwater. Hydrogeological investigations in these experimental field found the mean groundwater table at depth of 1.43 m. Shallow groundwater table and local high permeability of sediments caused fast infiltration of rainwater into the aquifer. The calculation estimated that the infiltration time are within the range of a few days. The contact time between the water and sediments is short; for this reason high concentrations of soluble ions in analysed groundwater are released probably not only by the weathering of aluminosilicates and carbonates in the sediments, aerobic decay of organic matter but mainly by impact of agricultural and traffic pollutants. Important trends were observed in this shallow groundwater. Analytical data indicates that chemical composition of the water in zone of the groundwater table fluctuation differs from that of the percolation water and groundwater. Only the magnesium concentration in the groundwater is roughly constant, whereas other ions concentrations vary widely. The SO4exp.2-, Clexp.-, NO3exp.-, Naexp.+ contents and HCO3/CO2 in this zone are similar to waters from the aeration zone, and the HCO3exp -, Ca2exp.+, K+, total CO2, aggressive CO2 contents, are similar to waters from the saturation zone. For this reason chemical composition of water in zone of the groundwater table fluctuation will be considrered separately