The joint venture (JV) team Galliford Try Costain Atkins (GCA) has begun process commissioning a wastewater extension for United Utilities.

The £200 million project for the company's Liverpool wastewater treatment works is one of the largest AMP5 projects in the UK.

The extension has been built in the redundant Wellington Dock next to the existing waste water treatment works in neighbouring Sandon Dock.

Works involve a secondary treatment process including a 16-cell, two storey, 21 metre high sequencing batch reactor (SBR) plant, which will be the UK's first multi-storey CASS (Cyclic Activated Sludge System) SBR.


When operational next year, the treatment works will be capable of processing 4750 litres per second of wastewater.

Andy Fielding, GCA JV Innovation Champion said: "Commissioning is on programme and going well. We started at the end of April and by 26th May six of 16 cells had been successfully commissioned and are now on a four-hour automatic cycle as planned.

"It’s been a very busy time getting everything ready for commissioning. Recently that’s included preparing the new high voltage switchgear and getting the electrical power connected to commission the SBR feed pumps and aeration blowers. We’ve also been testing the 2.2m diameter large bore pipe.

"The main challenge however is getting the new SBR process established without affecting the existing works. The target is to get all 16 cells process commissioned by the end of July."

United Utilities Process Engineer Robert Molloy said: "The process commissioning of the SBR has gone very well with effluent quality as good as expected at all times."

(LM)