Systems and methods are described for identifying and validating a fugitive gas leak. The system identifies the onset of a leak, tracks its persistence, and subsequently, notes its gradual disappearance after repairs are initiated. The method comprises initiating an observation period which serves to characterize the behavior of the anticipated leak if it exists. Extracting the underlying distributions of the parameter space for the anticipated leak over an observation period. Data is collected over incremental steps and compared to the current reference distributions. When the test period is complete, the observation window is moved forward to include the data over the validation span. The procedure thus repeats, with an updated reference distribution and re-initialized validation period.