Infiltration of inorganic compounds from the Glatt River, Switzerland, into a groundwater aquifer

Sodium, potassium, calcium, magnesium, strontium, chromium, copper, zinc, cadmium and lead, together with chloride, nitrate, sulphate and phosphate anions, were measured in water samples from river and groundwater at an experimental field site. Groundwater concentrations of these species were mainly determined by concentrations in the river, but concentrations of nitrate, phosphate, chromium, copper, zinc, cadmium, and lead varied seasonally near the infiltration site. These variations were probably triggered by temperature dependent biological processes influencing pH, redox potential and complexing agents. Manganese behaviour was controlled by redox potential and in turn influenced the solubility of heavy metals through coprecipitation and redissolution. Inorganic pollution in the Glatt river was much below drinking water standards, but cadmium levels reached critical limits for aquatic organisms.