The scope of the thesis aims at application of Statistical Process Control (SPC) in the water treatment process. The SPC is a method of using statically-based tools and techniques to manage, control and improve the process. The method ensures effective monitoring, enables timely correction and enhances the quality of the process itself. Every process has to be controlled, and control involves recording significant data. The first part of the paper briefly describes the fundamental concepts related to the SPC method and the way it is applied. After getting acquainted with the methodology of the SPC method, basic water treatment processes have been described with regard to the water origin and end use. The water treatment process most often encompasses a series of procedures for removing or reducing concentrations of certain substances. In the continuation of the work, the legally prescribed metric of the end product (water) is described in detail. In the central part of the work, the recording and analysis of the real-case water treatment process was carried out and a functional flow chart was created. The SPC method was implemented precisely on this particular process, and the process quality measure was defined by the removed concentration of the monitored parameter (three parameters were monitored: ammonia, iron and arsenic). At the end of the work, there is a proposal for improvement of the water treatment process considering legally prescribed water quality level. Ultimately, conclusions were made and presented.