Mill Creek Interceptor – Contract 1

Completed in 2003 by Mole Constructors, the Mill Creek Interceptor – Contract 1 project consisted of approximately 12,900 linear feet of 12 ft 8-inch diameter tunnel excavated using a 152-inch Lovat Tunnel Boring Machine (TBM). Approximately 8,834 linear feet of the tunnel was in shale formation and supported using rock dowels and channel straps. The remaining 3,362 lineal feet were excavated in soft ground and internal steel ribs and wood lagging were used. The rock portion of the tunnel received a 120-inch cast-in-place concrete final liner and 108-inch cast-in-place concrete was used in the soft ground section.