Lemay Redundant Force Main (3,262 ft., 5 arches wide), Jefferson Barracks Tunnel (17,424 ft., 27.5 arches wide), Deer Creek Tunnel (20,064 ft., 32 arches wide)" width="742" height="759" class="size-full wp-image-560" /> Lemay Redundant Force Main (3,262 ft., 5 arches wide), Jefferson Barracks Tunnel (17,424 ft., 27.5 arches wide), Deer Creek Tunnel (20,064 ft., 32 arches wide)

Tunnels are a critical part of MSD Project Clear. These tunnels are designed to handle the wastewater needs of MSD’s service area well into the future by reducing pollution to our waterways and improving the water quality in our communities and neighborhoods. Most of these tunnels will be dug with Tunnel Boring Machines, or TBMs, that grind through the rock – in our region, primarily limestone – to create a space large enough for sections of pipe to be fitted. TBMs range in size according to the project requirements, and travel all over the world digging tunnels like these.