Photograph: Gina LeVay

Photographer Gina LeVay first became fascinated by the Sandhogs—the urban miners who dig city water tunnels—in 2003. New York had just been hit by a massive blackout, and she started looking into the infrastructure of the city as a possible subject for her M.F.A. project at the School of Visual Arts. Five months later, after lobbying the Department of Transportation, LeVay found herself burrowed underground, 800 feet below Manhattan, with the ‘Hogs. “I was overwhelmed by the organic beauty of the tunnels,” LeVay tells us. She was at  powerHouse arena on Friday evening to celebrate the release of Sandhogs, a photo book that documents what she saw in the tunnel from ‘03 to ‘08. “It was loud, chaotic and crazy, with buses and trains going back and forth. I was struck by the scale of it, and the fact that nobody knew about this underground life.” And of the Sandhogs—several of whom were in attendance at the book party—she says, “They’re a very welcoming and tightly knit group.”

Mining has ended in the sections of the tunnels that LeVay photographed, and soon the three main portions in Brooklyn, Queens and Manhattan will have 1.5 billion gallons of water flowing through them.