In this study we analyzed a heavily damaged sewage system, exposed to microbial induced concrete corrosion (MICC). Understanding the causes, the underlying reaction mechanisms and environmental controls of MICC is crucial in order to provide sustainable restoration strategies. Various decisive parameters for detecting alteration features were determined in the field and laboratory including (i) temperature, pH, alkalinity, chemical composition of the solutions, (ii) chemical and mineralogical composition of solids, and (iii) concentration of gaseous H 2 S, CH 4 and CO 2 within the sewer pipe atmosphere. Focus was laid on stable sulfur, oxygen and hydrogen isotope data, which were used to decipher individual microbiological reaction mechanisms.