A short analysis of the contemporary techniques of water disinfection as well as of the effects arising from the magnetic treatment of water is carried out. The experimental results of water disinfection in constant magnetic and electric fields are presented. The maximum disinfection efficiency exceeds 99%. A theoretical model is developed that describes the effects arising in water after its treatment by constant magnetic and electric fields on the basis of “free” dipoles. The anomalous properties of water are shown to be retained more than two hours after its treatment. It is rather important that the expenditure of energy in the techniques considered is virtually nil.