Microbiologically induced corrosion (MIC) of concrete sanitary sewers is a common problem that demands a large rehabilitation investment every year. MIC is the result of dilute sulfuric acid (H2SO4) dissolving the cement matrix. The acid is produced by a complex series of chemical and biochemical reactions. Hydrogen sulfide (H2S) is produced by sulfur reducing bacteria (SRB) in the liquid phase, and then in time, this gas is converted by sulfur oxidizing bacteria (SOB) into H2SO4. The last conversion occurs above the liquid level under aerobic condition. The objectives of this paper are (1) to present a literature review of MIC processes and factors influencing them and (2) to discuss control mechanisms and authors’ experience on development over years in understanding MIC of concrete (MICC) in sanitary sewerage environment (SSE). Published papers were identified that reported MICC in SSE for the past 30 years. The literature review and authors’ on-site and laboratory investigations suggest that MIC of concrete is a complex process that involves varied surface interactions. The addition of liquid antimicrobial additive as per standard procedure shows resistance of concrete to MIC and its direct relation with mixing time of admixture. Many empirical inputs like corrosion areas, corrosion rates, impact of cement and aggregate types varying with installation, and repair of sewer structures are identified. The review results show variation in corrosion rates and other empirical inputs obtained on-site and through laboratory studies due to different testing procedures. Further research is needed to establish quantitative relations between empirical inputs related to MICC in SSE. Identification and development of more effective coatings and safe antibacterial agents will help inhibit colonization of SOB over exposed sewers and better understand environmental microbiology.


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Microbiologically induced corrosion (MIC) of concrete sanitary sewers is a common problem that demands a large rehabilitation investment every year. MIC is the result of dilute sulfuric acid (H2SO4) dissolving the cement matrix. The acid is produced by a complex series of chemical and biochemical reactions. Hydrogen sulfide (H2S) is produced by sulfur reducing bacteria (SRB) in the liquid phase, and then in time, this gas is converted by sulfur oxidizing bacteria (SOB) into H2SO4. The last conversion occurs above the liquid level under aerobic condition. The objectives of this paper are (1) to present a literature review of MIC processes and factors influencing them and (2) to discuss control mechanisms and authors’ experience on development over years in understanding MIC of concrete (MICC) in sanitary sewerage environment (SSE). Published papers were identified that reported MICC in SSE for the past 30 years. The literature review and authors’ on-site and laboratory investigations suggest that MIC of concrete is a complex process that involves varied surface interactions. The addition of liquid antimicrobial additive as per standard procedure shows resistance of concrete to MIC and its direct relation with mixing time of admixture. Many empirical inputs like corrosion areas, corrosion rates, impact of cement and aggregate types varying with installation, and repair of sewer structures are identified. The review results show variation in corrosion rates and other empirical inputs obtained on-site and through laboratory studies due to different testing procedures. Further research is needed to establish quantitative relations between empirical inputs related to MICC in SSE. Identification and development of more effective coatings and safe antibacterial agents will help inhibit colonization of SOB over exposed sewers and better understand environmental microbiology.


[Access the Conference Proceedings Paper on ASCE Library](https://ascelibrary.org/doi/10.1061/9780784483602.025) 

Microbiologically Induced Corrosion of Concrete in Sanitary Sewerage System: A Review of Processes and Control Mechanisms

Papers from sessions of Pipelines 2021, held virtually August 3–6, 2021. Sponsored by the Utility Engineering and Surveying Institute of ASCE. The conference provides a forum for pipeline engineers and practitioners from all around the world to share their experiences in meeting the challenges of today's pipeline infrastructure. This premier industry event has become the conference of choice for utility and pipeline owners, design and consulting engineers, contractors, manufacturers, suppliers, students, educators, researchers, and pipeline professionals. The conference includes surveying as it relates to pipeline and utility projects. This event will provide a dynamic and inspiring venue for participants to share and gain valuable knowledge related to planning, designing, constructing, renewing, operating, managing and maintaining the pipeline assets.

[Paper Proceedings](https://doi.org/10.1061/9780784483602)

Conference DOI: https://doi.org/10.26226/m.6454f875c8d4320012b71046