The scope of works included:

• Removal and disposal off-site of the existing fibreglass odour
• Control hood for the inlet works mechanical screens
• Re-installation of the existing stainless steel covers to the inlet works mechanical screens, including design, fabrication and installation of replacement Grade 316 stainless steel covers where the existing covers were not suitable to be re-used
• Replacement of the odour control covers to the inlet works to achieve specified functionality and to accommodate new flow control devices
• Removal of the existing penstocks and design, supply and installation of a new wall-mounted proportional weir penstocks
• Design, supply and installation of new stop boards
• Repair, insertion of a bonded internal liner and hydrostatic seal testing of manhole 1A
• Making good affected concrete surfaces and reinstating the integrity of the existing protective coating

Close liaison with the plant’s operations team was essential, as the works were carried out under brownfield conditions while the existing plant remained in operation.

For some elements of the works involving installation of temporary flow diversions, valve installation and cutting in of pipes, it was necessary to suspend and detain sewage flows for short periods