Bewsey UID/CSO Chamber

The project entailed the construction of a new combined sewer overflow (CSO) chamber located upstream of the existing pumping station.

The new CSO chamber included the installation of an electrically powered screen 8.4m in length which would filter sewage when storm conditions arose.

Two major sewers then had to be diverted to ensure all storm flows passed through the new system. This involved the installation of nearly 300 linear metres of new concrete sewers (1.80m, 1.60m and 1.50m diameter) and 10 new manholes generally 3.0m diameter and constructed at depths of up to 9 metres. To add to the difficulty of the task, the site was sandwiched between a tidal river and a canal and all the works were below normal water table level.

All work items were completed whilst maintaining existing flows on the network so extensive over-pumping was utilised. The project was also closely monitored by the Environment Agency to ensure that the nearby watercourses were not polluted

Close liaison and planning was necessary with UU framework suppliers to ensure key programme dates were achieved without issue.

The scheme was undertaken by Bethell on a ‘Design and Construct’ basis and we developed the initial outline design that was issued by UU at tender stage.