Sandhogs are New York's legendary urban miners, rock-hard tough guys who have been tunneling underneath the city for over a century, providing the subterranean infrastructure for the nation's largest metropolis. For decades, the hogs have been digging the largest public works project in the history of the Western Hemisphere. New York's entire water supply depends on this tunnel's success, but it's a race against time and the project is fraught with peril. It is up to the Sandhogs to prevent total catastrophe. This feature doc captures Local 147's entire story, for the very first time.