Microbiologically influenced corrosion in water utility systems: a cross-system review of knowledge gaps, standards, and mitigation challenges
Anette Alsted Rasmussen, Judit Knisz, Gregor J. G. Gluth, Bo Højris, Elsemiek Croese, Marina Vuković, Torben Lund SkovhusABSTRACT
Graphical Abstract Overview of possible locations of microbiologically influenced corrosion in water utility systems: potable water systems, heating water systems, fire sprinkler systems, and wastewater systems. Illustration showing where microbiologically influenced corrosion may occur in water utility systems.
Microbiologically influenced corrosion (MIC) is a persistent and often underrecognized challenge across water utility systems. This review presents an integrated cross-system assessment of MIC in potable water, heating water, fire sprinkler systems and wastewater infrastructure, drawing on knowledge from materials science, microbiology, corrosion engineering and operational practice. The analysis identifies shared corrosion drivers such as water stagnation, oxygen concentration gradients, heterogeneous biofilm development and the formation of protective or corrosive deposits, as well as system-specific vulnerabilities linked to design, operating conditions and material combinations. The review also highlights inconsistencies across existing standards and diagnostic practices, particularly regarding sampling, interpretation of microbial activity, and evaluation of material performance. A cross-system synthesis reveals recurring gaps in data accessibility, limitations of bulk water monitoring and the need for diagnostic approaches that integrate chemical, microbiological, and material evidence. Although emerging molecular techniques offer promising improvements, their use remains uneven across sectors. Key knowledge gaps are identified, and pathways are outlined for harmonized, sector-specific protocols that support more reliable detection, improved mitigation strategies and stronger alignment between scientific understanding and operational practice. The synthesis provides a foundation for future research, standard development and coordinated action to enhance the resilience and sustainability of water infrastructure.