This powerpoint presentation begins by providing background information on the integrity monitoring methodology for microfiltration/ultrafiltration (MF/UF) membranes. The objectives of the study were to have a decision-aid tool for operators that: gives them the integrity level of their plant without having to disconnect all the modules; and, that indicates whether the measured level effects plant effectiveness, requiring immediate repair. Methods included: developing a model that uses the air flow rate throughout a defect during the air pressure test for predicting the microbial Log Removal Value (LRV) of the unit; conducting challenge tests with MS2 phages with various calibrated defects on the membrane fibers at bench-scale in order to validate the model and the selected assumptions; and, evaluating the validity of the model at full-scale. Includes figures.