Each time you pull the lever on your toilet, the water disappearing in that comforting swirl begins a long, underground journey through the engineering marvel that is the sewage system of the metropolitan area. The waste first travels through a dark labyrinth composed of everything from 10-inch pipes to cavernous, 10-foot culverts large enough to be traversed by a speedboat; in all, 550 miles of sewer ducts--the distance from Minneapolis to Rapid City, S.D.--lace the ground under... More >>>