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HomeOur projectsBlackburn UID

Blackburn UID

The Blackburn UID Scheme was awarded in May 2010 and is part of United Utilities overall strategy to reduce the impact of discharges from the existing assets on the Rivers Blakewater and Darwen and the Leeds-Liverpool Canal to levels acceptable to the Environment Agency. 

VolkerStevin and GHA developed the outline design to construction stage. The design included Detention Tank, Valve Chamber, CSO Chamber, combined deep sewer drainage and manholes, M & E pipework, pumps and control kiosk.  The 6.5m dia x 13m deep storm shaft was designed to hold 265m3 of and return this into the drainage system when the storm flows subsided.

It was a complicated project due to the size of the site and the depth of the structures and drainage.  The site was set within an ongoing social housing development on three sides of the site and resident's access had to be maintained throughout the contract and this divided the site into a construction area and a separate storage area.  Materials were delivered on a "just in time" basis, with the mechanical components stored at our Morecambe yard and brought to site for immediate installation.

The works also had to be planned around underground services and the replacement of the existing sewer on line.  All the structures were founded in rock and the new drainage and manholes including the 800mm dia directional boring were also installed in rock. The main structures had precast concrete covers weighing 18t.

A temporary propping system was designed and installed to support works at depths in excess of 6metres. 

The scheme is now operational and will improve the water course quality by reducing the storm discharges.

Key Subcontractors included:

  • Galt for the Shaft and tunneling
  • Apex Electrical for Electrical installations
  • Lloyd Morris for MCC and Kiosk
  • Paul Newton for Mechanical Installation

Facts and figures

  • Client:
    United Utilities
  • Value:
  • Commencement Date:
    July 2010
  • Completion Date:
    February 2011
  • Project categories
    Water and utilities