In the Upper Romerike District the lakes possess widely different chemical characteristics depending on their hydrological conditions. The most dilute lakes are fed only by precipitation, and the more concentrated ones by ground water. In the precipitation fed lakes the total ionic concentration was similar to that of the average precipitation, but the ionic ratio was different. Ionic sorption and exchange affected mostly calcium which decreased in concentration while the monovalent ions increased. The ground water fed lakes were dominated by bicarbonate, and their ionic proportions were constant regardless of total concentrations. The percentage composition was: Ca: 82%, Mg: 10.1%, Na: 6.5%, K: 1.4%, HCO3: 78.3%, S04: 17.1%, Cl: 4.6%.
- Received January 12, 1977.
- © IWA Publishing 1977