Sewage-treatment plant construction work

Tender description

Design, construct and commission an upgrade to the current Beckton Sewage Treatment Works (STW) with the scope summarised as follows: — final effluent tide locking, — ASP4 extension and increase ASP3 blower capacity (ASP stands for Activated Sludge Plant), — inlet works upgrade, — sludge improvements, — site wide capital maintenance, — engineering design services. Contract award is expected to be November 2019 and the project is required to be complete by September 2023. The contractor will be required to carry out the works without adversely impacting on the integrity of the STW and in accordance with the current permits. Beckton Sewage Treatment Works (STW) is Thames Water’s and the UK’s largest STW. It is located in the London Borough of Newham, east of London on the north bank of the River Thames. The design flow to full treatment capacity is 27,04 m3/s with flow received from the catchment being up to 33 m3/s. The works which are the subject matter of this contract opportunity are to provide for growth, resilience and consent compliance to a design horizon of 2036 with the population equivalent (PE) projected to be 4 540 000 and the contract will also include related design and engineering services and associated equipment. During operation of the Tideway pumping station from October 2022, up to 12 m3/s will be discharged but the rate will need to be controlled to ensure that flow received at the Inlet Works does not exceed 27 m3/s. The scope of this project comprises the following core activities: — upgrade and extension to the Inlet Works to cater for pro-longed periods of operation of the Tideway pumping station, — provision of medium screens and screenings handling plant at the Existing Inlet Works, — replacement and upgrade of Inlet Works diesel powered generator, — extension to ASP4 secondary treatment process capacity to provide resilience against growth, the operation of the Tideway pumping station and high ammonia load peaks during storm loading conditions, — provision of ASP4 additional blower capacity including a new Blower House building to provide resilience against high ammonia load peaks during storm loading conditions, — replacement of ASP3 air-lift conveyance mechanism for discharging final effluent into the River Thames with low-lift pumping stations, — provision of pumping station’s diesel powered generators, — provision of ASP3 additional blower capacity including new Blower House buildings or containerised solutions to provide resilience against high ammonia load peaks during storm loading conditions, — additional sludge buffering and balancing tanks, and raw sludge thickening capacity to provide resilience against Sludge Stream bottle-necks restricting Final Effluent Stream operation, — extension to the cake barn, — capital maintenance works for replacement and upgrade of HV/LV (11 kv/6 kv) transformers and HV/LV (11 kv/420 kv) switchboards, — modifications to the power management system, SCADA (supervisory control and data acquisition) and the tiled mimic panel.