Thames Tideway Tunnel is a 25 km (16 mi) combined sewer under construction running mostly under the tidal section (estuary) of the River Thames across Inner London to capture, store and convey almost all the raw sewage and rainwater that currently overflows into the estuary. Our main works consist in building the Combined Sewer Overflow (CSO) EARPS structure that will intercept the flows from the existing Thames Water sewerage assets