London's £4.5bn Thames Tideway Tunnel, a 25 km sewage storage tunnel, begins operations to reduce River Thames pollution and improve water quality.

London's Thames Tideway Tunnel, a £4.5 billion super sewer, has begun operations to protect the River Thames from sewage pollution. Spanning 25 kilometers, the tunnel features four of 21 valves activated, designed to capture and store up to 1.6 million cubic meters of sewage. Once fully operational in 2025, it aims to reduce river pollution by nearly 95%, significantly improving water quality for the city. The project took eight years to construct.