Chalton Water Recycling Centre

Chalton works in Bedfordshire is now the largest sand filtration unit in Europe, designed in response to a significant change in the standards required for discharge.

Anglian Water awarded Colloide the contract with the purpose to reduce ammonia and solid levels from the previous treatment plant. Anglian Water Services was advised that consent had to change from 5 mg/l ammonia to 1 mg/l ammonia. The site also experiences issues with localised overflows under high flow events through the inlet works and primary tanks. As part of the project the team had to address this issue by balancing/holding of the high flows.

The Chalton Water Recycling Centre takes half of Luton’s sewage, with the nearby Flitwick Moor a sensitive wildlife site the water needed to be treated to a very high standard to remove ammonia. Reducing disruption as much as possible to nearby residents during construction also being a priority, there were a lot of variables to consider in planning.

The solution from Colloide involved the design and build of our standard continuously washing nitrifying sand filters. The unusual element to this design was the number of filters used. A total of 30 (No.) filters, in six streams of five was proposed with a cascade flow distribution system. As with the other design on site decisions were taken with the core principles in mind, specifically:

  • Pipework and cabling was to be above ground wherever possible.
  • All 30 (No.) filters were exactly the same, pipework support gantries and access ways were all designed to be brought to site, as pre-assembled units in order to reduce site assembly time and reduce design time.
  • Standard product MCC kiosks were used. Due to the amount of power cables from the generator and transformer and a necessary road crossing a standard product cable trench was used.
  • The new generator was a standard product, supplied in a container for speed of assembly on site.

“The filters came in on the back of a lorry and they were fitted together like Lego” says engineering project manager Alison Taylor describing the construction of our newest water recycling plant.

Due to the processes and techniques used on the scheme such as standard designs, project rehearsals, constructive collaboration the project has saved over 45% on embodied carbon and over 4 months on the typical assembly period for a project of this type once on site.

Click here to read more on our solution and approach to this project at Chalton with support from our supply chain:

Alpha Tanks  | Kaeser Compressors  TES Group DPS Group Global PMcK Electrical | R J Smyth Engineering | Bollfilter Protection Systems