Understanding microbial ecology to improve management of drinking water distribution systems

Microorganisms in Drinking Water Distribution Systems (DWDS) and in particular the microbial communities that form biofilms on infrastructure surfaces, drive critical processes impacting water quality. This paper reviews knowledge, research approaches and monitoring methods to consolidate understanding of the microbial ecology of DWDS. The review highlights how microbial characteristics and subsequent behaviour can be broadly classified as common or complex. Common behaviour relates to the ubiquitous and continual development of biofilms, consistent core communities and mediated material accumulation. In contrast, the complex aspect relates to the shape, structure and composition of the microbiome, defined by site specific properties such as supplied source water, pipe material and hydraulic regimes. It is shown how the latest microbial tools and techniques can be applied to increase our understanding of DWDS ecology and how water utilities are starting to use this knowledge. This is not because of regulatory requirements, but in recognition that they provide valuable information facilitating pro-active management and operation benefits to these critical yet ageing systems, protecting water quality and public health in the process.