The Milwaukee Metropolitan Sewerage District (MMSD) is planning to build an 11.9km 6m diameter tunnel capable of holding 89 million gallons sewage, as part of a wider scheme to construct a system of tunnels with a capacity of 116 million gallons.
It follows a report by the Wisconsin Legislative Audit Bureau criticising a recently constructed network of tunnels under the city that failed to significantly reduce the number of sewer overflows in the Milwaukee area. Known as the Deep Tunnel, 15.13km of tunnel, at depths of up to 99m, were built in the late 80s, early 90s to contain the billions of gallons of raw sewage that overflowed annually into the local waterways, including nearby Lake Michigan.
See October’s issue of T&TI for more details
