Thames Water Utilities has updated the qualification system for construction companies wishing to bid for work on the £2bn Thames Tunnel scheme.
The tunnel, the second phase of the Tideway scheme, will comprise a 30km-long seven-metre diameter interceptor sewer, plus 35 combined sewer outfall shafts.
Thames Water will appoint a delivery partner to develop a PPP model for the project.
The qualification system covers 30 different lots of work, including a five-year, £1bn water framework, which includes design and construction works on water mains, sewers, pipelines, tunnels, reservoirs, small network pumping stations.
A similar framework, also worth £1bn, covers design and construction works on sewage treatment works.
Suppliers already registered do not have to re-apply, unless bidding for new lots.