Intermittent Water Supply Impacts on Distribution System Biofilms and Water Quality

Intermittent water supplies (IWS) are routinely experienced by drinking distribution systems around the world, either due to ongoing operational practices or one off interruptions. During IWS events changing conditions may impact endemic biofilms leading hydraulic mobilisation of organic and inorganic materials attached pipes walls with a resulting degradation in quality. To study on microbiological physico-chemical characteristics water, an experimental full-scale chlorinated pipe facility was operated over 60 days under realistic allow for biofilm growth investigate flow resumption behaviour post-IWS 6, 48 144 hours. Turbidity metal concentrations showed significant responses restarting, indicating changes, greater than 6 hours generating more turbidity hence discolouration risk. The increase pressure when system restarted substantial total cell counts, while subsequent increases led elevated metals concentrations. SUVA254 monitoring indicated that shorter times non-water supply increased risk aromatic compounds disinfection-by-products formation. DNA sequencing increasing resulted relative abundance potential pathogenic microorganisms, such as Mycobacterium, Sphingomonas, fungi Penicillium Cladosporium. Overall findings indicate result higher proportion compounds, which can potentially react chlorine However, minimising times, biofilm-associated impacts be reduced, yet these complex ecosystems much remains understood about how microbial interactions managed best ensure continued safe supply.