Urban CSO jack in Jersey

18 January 2012

Donaldson Associates will provide detailed design work for a ‘challenging’ underground connection. A 65m-long, 1.2m-diameter pipejack will make the connection to the Surface Water Link tunnel in St Helier, Jersey from a 7m-diameter secant piled shaft.

A new combined sewer overflow below the street level will be constructed to divert surface water into one pipejack, and foul sewage into another.

Donaldson Associates will also supervise additional site investigation, prepare contract documentation for the client, the Transportation and Technical Services Department of the States of Jersey.

A Donaldson Associates spokesman said, “Particular challenges include ensuring that the works do not draw down groundwater from the superficial deposits and thus cause settlement to historic buildings build on raft foundations. Also, limiting the effect on adjacent businesses, residents and the Jersey Art Centre.”