Purging in the natural gas industry refers to the process of removing or introducing typically combustible gases from piping or equipment systems.  While it is a necessary practice for maintaining the integrity and safety of gas systems, it can pose a significant environmental impact when not managed properly.  One major concern is the release of methane, a potent greenhouse gas, during purging activities, especially against the backdrop of a rapidly changing regulatory environment.  Recent regulatory developments now impose taxes when resource utilization efficiencies are not met thereby changing the way the industry views this historical practice. The American Gas Association's purge manual highlights the importance of minimizing such emissions through various mitigating technologies.