Recent research studies and surveys have shown that air pockets in wastewater transmission systems cause extensive damage and hindrance. Air pockets decrease flow capacity, they induce significant head losses and energy losses, they prompt serious corrosion, and they can trigger and/or enhance pressure surges. In the advent of concern for energy conservation, more and more research is invested in studying the effect of air pockets on flow efficiency and energy consumption. Conclusions are that air pockets have a very significant impact on these, especially in wastewater force mains.