Columbus, the capital of the State Ohio, like all large cities in the USA, is complying with the requirements to abolish CSOs (Combined Sewer Overflows) in future. The aim is to prevent mixed water from running into rivers and lakes untreated in cases of heavy rains or overstrains of the wastewater system. The main concern in Ohio is that wastewater is no longer drained into the Olentangy and Scioto Rivers. A new sewage collector is to lead large quantities of water to the intermediate reservoirs and the treatment plants.
For the demanding geology in Columbus, Herrenknecht engineers designed a high-tech machine. The machine is designed to master both the hard rock and the high groundwater pressures expected. In June 2012, the machine started drilling through Columbus' underground meter for meter. After best weekly performances of up to 136,8 meters, the Herrenknecht EPB Shield broke through the walls of the target shaft on September 4, 2015.