An overview of biofilm formation in distribution systems and its impact onthe deterioration of water quality

The impact of biofilms present in water distribution systems on the microbi al quality of potable water is reported in this review. The issues cover ed include the composition of bioflims, factors governing their formation and the effect and significance of biofilms on the microbial quality of drinki ng water. The review addresses the main factors governing the formation of biofilms such as the types of disinfectants and residual concentrations, re sistance of bacteria to disinfectants, the influence of piping material and the effect of temperature. Methods for the enumeration of bacteria in biof ilms as well as emerging technologies for in situ monitoring of biofilms ar e discussed. Suggested control measures for managing and controlling the pr oblem of biofilm formation in potable water distribution systems to ensure potable water of an acceptable microbiological quality are dealt with.