In aquifers containing iron and manganese rich groundwater, groundwater quality can be improved by injecting an oxidizing agent into the aquifer to promote precipitation of iron and manganese. In this study, oxygen rich water was recharged by an injection well. Concentration measurements were carried out around the well at different locations to find out the demand for oxygen to oxidize iron (II) within the aquifer. Evaluation and interpretation of the field experiments were made by comparison with a mathematical model. The experiments and in particular the model calculations show that the method is practicable and economic.