DrainsAid, the innovative drainage and sewerage division of award winning company Peter Duffy Limited, recently completed a sewer rehabilitation project underneath a dual carriageway.
Long-standing partner Yorkshire Water awarded DrainsAid a contract to reduce pollution incidents arising in Bowden Housteads Woods in Sheffield. A high pollution risk was identified in a severely damaged and root infested sewer beneath the Sheffield Parkway dual carriageway and further into the woodland.
The sewer diameter changes from 450 mm to 375 mm and passes beneath one of the Sheffield’s busiest transport routes. At points in the sewer, intruding tree roots reduced the flow capacity to 20%, risking both flooding and polluting of the surrounding areas.
The sewer serves 413 properties and carries domestic foul water under the carriageway and through the woodland alongside a small beck. During the rehabilitation work managing the risk of pollution and not causing disruption to road users was of paramount importance to Yorkshire Water and The Highways Agency.
Drains Aid devised an innovative solution to overcome these problems and fully restore the sewer. The solution was to overpump the flow over the dual carriageway by making use of a nearby footbridge. To improve access, a new manhole was constructed at the approach to the footbridge, however, this restricted the access to the footbridge and therefore to access the footbridge safely an alternative public footpath was constructed for pedestrians.
DrainsAid then designed a liner for depths of up to 7m and installed it in three sections along the sewer, underneath the dual carriageway and through the woodland. The team used hot water to cure the liner and reach maximum strength.
Fast, effective result
Working quickly and efficiently, DrainsAid completed the project in full with minimal disruption. 120m of 450mm pipe and two 45m sections of 375mm pipe were relined and rehabilitated. In total it took just two weeks to complete the project with no obstruction to traffic and little inconvenience to pedestrians. Yorkshire Water and The Highways Agency were satisfied with DrainsAid’s work and the end results, and the area is now adequately protected against any potential pollution.