39th Street Conduit – The Largest Intercepting Sewer in the World in 1905

The 39th Street conduit is the Metropolitan Water Reclamation District of Greater Chicago's (District's) oldest and largest intercepting sewer. The most cost-effective method to rehabilitate the 6.10 meter (20 foot) diameter brick sewer was to complete the project in two phases, limiting service disruption and flooding risk. Phase 1, completed in 2012, consisted of a deep tunnel, connecting structures, sewers, and drop shafts which will divert flow from the service area during the Phase 2 rehabilitation. The District's design criteria require the new lining system, installed in Phase 2, to carry the entire structural load without relying on the existing brick structure. The new lining system will also reduce infiltration. The District is currently investigating lining alternatives and other cost-effective methods of rehabilitating the 39th Street conduit.