The Hultman Aqueduct is an 18-mile-long pressure conduit extending from near the Wachusett Aqueduct terminal chamber in Marlborough to a point in Weston near the Charles River. The aqueduct includes a 9700′ segment of cut-and-cover with 12’6″ steel cylinder reinforced concrete pipe; a three-mile rock tunnel beneath Sudbury Reservoir; 13 miles of 11’6″ steel-cylinder reinforced concrete pipe; and a 170′ twin-tube segment and a 170′ twin-tube segment below Norumbega Reservoir in Weston. Structures associated with the Hultman are a semi-circular diversion dam on the Wachusett open channel, an intake structure, a headhouse at Shaft 4 (below Sudbury Dam), and a gatehouse and chlorine storage structure at Norumbega Reservoir. Contractors for the work included the Weston Construction Co, Boston; B.A. Gardello, Boston; The American Concrete & Steel Pipe Co., Los Angeles; and Carlo Biachi, Framingham. Consulting architects for the Shaft 4 headhouse and Norumbega Reservoir gatehouse was the Boston firm of Densmore, LeClear, & Robbins.