Cost and complexity of redevelopment of a large waste water treatment works in Sheffield has been eased through the use of deep excavations in the placed of sheet piled solutions.
ETM – a joint venture of Galliford Try and Aecom – is working under a target cost contract on the upgrade of Woodhouse Mill for Yorkshire Water while the existing plant remains operational, which has led the work to use some unconventional techniques.
ETM took the decision to use a battered slope excavation for construction of the 7m deep aeration lane tank rather than using a sheet piled approach in a bid to reduce costs and avoid damage to existing tanks next to the location of the new tank. The technique is also being used on the filter sludge tank and inlet chambers in order to avoid issues with driving piles directly about two live sewers that cross the site.
According to ETM project manager Mark Godfrey, the work has gone well and is on track for completion next summer.