The transect of the bank filtration site at Lake Tegel is characterized with regards to their redox conditions using a Cluster analysis. Four different groups of observation wells could be found, enabling the derivation of a redox zoning with horizontal boundaries, which are moving downward during winter time. At the same site, Regression analysis served to examine influencing variables on the reduction of the pharmaceutical Carbamazepin during bank filtration. Two different regression models for summer and winter time were found, with each of them including the standardized temperature and the travel time as influencing variables. Whereas during winter time the redox conditions seem to have a significant influence on the reduction of Carbamazepin, the same influence could not be found for the reduction of Carbamazepin during summer time.