After inspection of the quay wall, potential and wall thickness measurements were carried out. In addition, samples of corrosion products were taken for microbial analysis and microbial related damage analysis (SEM-EDX and volatile sulfide determination). The results showed that corrosion related microorganisms were often found in corrosion products scratched from the surface. Sulfur has been found in corrosion products indicating possible activity of SRB directly on the damaged surface. Detection of gaseous sulfide from the samples of corrosion products confirms this. Potential measurements showed variable values ​​between -0.7 and -1.02 V vs sat Ag / AgCl. Anodes were placed on the new part of the structure only (D1). The more distance between the anode and the position of the potential measurements, the higher the measured potential. The potential was not low enough along the older part of the sheet pile. Which resulted in severe corrosion damage and large perforations, while the new part was adequately protected by the sacrificial anodes. All this leads to the conclusion that MIC plays a role in the observed damage of the quay wall structure and that the part where anodes are installed is protected from microbial activity if the potential is below -0.9 V vs sat Ag / AgCl.