Three case studies involving waterside pitting of copper and carbon steel tubing due to MIC are presented. In each case the morphology of the affected surface and its elemental composition determined using SEM/EDXS are discussed. Results of metallographic examination also are presented. It is shown that certain morphologies of the affected surfaces can only form in the presence of a living organisms. This finding could aid metallurgical evaluations especially if sample is dry and water from the system is not available for testing to positively identify the presence of bacteria.