The impact of biofilms on water quality in long pipelines

Abstract

Limited water availability and increased water demand necessitates the use of long pipelines to distribute potable and non-potable water for human consumption or other purposes. The effects of microbial growth and activity on the quality of distributed water have been studied for many years, although in recent years much of this focus has shifted to understanding the effects of biofilms, rather than planktonic microorganisms, on water quality. Recently, it was estimated that 95% of all biomass in water distribution systems is in the form of pipewall biofilms, with only 5% of all biomass in the bulk water phase. Under favourable conditions, biofilms can impact water quality by increasing disinfectant demand, creating taste and odour problems, harbouring opportunistic pathogens and contributing to the potential for discoloured water events. More research is required to inform the development of guidelines for the management of biofilms in long pipelines to ensure the delivery of safe drinking water and to minimise impacts on water quality.