The existing works at Sandon Dock will be extended into the redundant Wellington Dock, resulting in a plant able to cope with 11,000 litres of waste a second.
Dredging of Wellington Dock has already taken place and construction work will start next month. It is scheduled to take up to four years to complete and United Utilities estimates that up to 350 people could be employed to work on the scheme. The treatment facility will be sunk into Wellington Dock. Coping stones, dock features and furniture will be retained where possible.
Liverpool City Council's planning department approved the plans at a meeting on Tuesday this week. The plant will serve one million people in Liverpool from Crosby in the north to Speke in the south.
United Utilities principal project manager Mark Walker said: "Our existing plant has played a key role in the clean up of the River Mersey and the new works will ensure we can continue to build upon that legacy.
"The expansion of Liverpool as a city down the years meant the current works were beginning to reach the end of their useful life. The new works will ensure we can continue to provide one of the city's most essential services for many years to come."
Got a story? Email news@theconstructionindex.co.uk