Added value:
Major refurbishment of existing water treatment works on live site.
This scheme is the biggest investment Boughton works has seen in its history and one of the most important investments for Dee Valley Water.

The works supply a population of 100,000, treating raw water extracted from the River Dee, and have a treatment capacity of 36 Ml/d. The existing process relies upon a mixture of slow sand filters, rapid gravity filters and pressure filters all of which are near life expired.

Halcrow are working with the client to ensure the new works are built and commissioned whilst the existing works remain in full operation.

Innovation:
The project is challenging as it requires a process design that can fit within the small available footprint and that can integrate with the existing process. Also the site is constrained with little available space for the new construction or access. Constructability is an important consideration in the design as it must allow the new works to be built and commissioned whilst the existing works remains in full operation.

Contract value is circa £12M and scope of the works include:
New 2 stage rapid gravity filter plant comprising sand filters and GAC filters
>> New treated water pump station
>> New chlorine contact tank, lime dosing facilities
>> New wash water recovery tanks
>> New sludge thickening plant
>> Extension to the existing control building and other refurbishment elements

Team work:
The initial phase of the scheme involved a 6 month study and outline design to determine the best refurbishment options.  This then led into the detailed design and construction phase. The scheme was let as a design and construction project with the contractor partners of Morrison and Enpure, supported by Halcrow, undertaking the study phase and developing the scope before being appointed the construction phase. The study work and scope development was undertaken in partnership with the client Dee Valley Water.