Services: Temporary works design, supply and installation of ground support system
The current outfall arrangement involves final effluent being pumped from a tidal pump house at the west of the works via a 1200mm diameter glass reinforced plastic (GRP) pipe which passes beneath a sea defence bund. From this point the outfall continues as a cast iron pipe to the outfall headwall. The proposed replacement outfall runs generally parallel to the sea defence wall for a distance of approximately 1400m from where it heads adjacent to Walney Channel. The foreshore is classified as a Special Area of Conservation, Special Protection Area, a Site of Special Scientific Interest and a RAMSAR (Wading birds).
Working for Farrans, Trench Control designed and installed the temporary works for the main pumping station for the new outfall works. Additionally, Trench Control designed and installed a pipe track for connection to existing structures. The design accommodated the difficult ground conditions which were encountered including loose reclaimed sands with high and tidal groundwater. The maximum retained height was in the order of 5m.