Anglian Water has improved the handling of surplus activated sludge (SAS) at its Whitlingham Water Recycling Centre (WRC) in Norfolk following the installation of new pump technology designed to cope with challenging sludge characteristics.
Whitlingham WRC, which serves a population of around 400,000, had experienced ongoing issues with SAS due to its thick and unpredictable consistency. The sludge frequently failed to flow evenly from two storage tanks, causing pumps to draw in air, back up tanks and create elevated mixed liquor levels, increasing operational pressure on maintenance teams.
According to Stuart Chatten, lead bioresources technician at the site, repeated stop-start operation meant SAS concentrations regularly exceeded target levels, creating compliance and efficiency challenges.
To address the problem, Anglian Water replaced its existing SAS pumps with Borger PL200 rotary lobe pumps, drawing on positive experience with Borger equipment already in use at the site for sludge belt pressing and digester mixing.
The new pumps have stabilised sludge drawdown from both tanks, reducing the need for manual intervention and improving process reliability. Chatten said the system now operates largely automatically, maintaining compliance and significantly reducing operator workload.
In addition, Whitlingham has upgraded its polymer dosing equipment, replacing older pumps that were difficult to maintain and source spare parts for. Compact Borger BLUEline AN040 pumps have been installed, delivering smoother operation and a more consistent polymer mix, while also allowing a reduction in polymer usage.
Borger pumps are also set to play a role in Anglian Water’s planned expansion of sludge treatment capacity at Whitlingham, which will see digesters replaced as part of a programme to double capacity and serve up to one million people.
Pumps prove to be smooth operators for Anglian Water
