Case Study:

Barrow in Furness WwTW Outfall

Client:

United Utilities

Principal Contractor:

Farrans Construction

Project Overview

Construction of a new 2.4 kilometre sea outfall pipeline, across Roosecote Sands, Barrow in Furness. The outfall extension was to improve dispersion of the final effluent in the Walney Channel. The construction and installation of the pipeline required stable and dry ground conditions.

Due to the high water table, tidal effect and nature of the ground conditions across the whole of the site, a simple opencut pipeline excavation would not be achievable.

Accreditations Include:

- ISO 9001 (Cert. No. 11653)
- ISO 14001 (Cert. No. 11653)
- ISO 45001 (Cert. No. 11653)
- Constructionline, Gold.
- Achilles UVDB Silver +
- CHAS Accredited Contractor
- Builders Profile Safe Contractor

Before and After

Solution

Alba Dewatering Services Ltd. (Alba Dewatering) was tasked with designing a dewatering system that would allow the pipe laying contractor to increase productivity in difficult site conditions.

The ground water control system’s design consisted of a wellpoint system being installed. All the wellpoints required Zone 2 filter media placing around the filter to increase the vertical permeability and avoid blockages caused by the movement of the tides.

All the suction pipes and discharge pipes were secured to the ground using ‘U’ shaped steel bars which allowed us to leave all the pipes in-situ during the ebb and flow of tides, only removing the pumpset. Taking less time to set up and drawdown the water after the tide, allowing the contractors to increase production.

The job proved that with careful design, planning, innovation and collaboration, success can be achieved even in the most challenging conditions.