This scheme was designed to alleviate the problem of raw sewage polluting the River Almond estuary at the village of Cramond. The area was particularly sensitive as we were dealing with a conservation village surrounded by “scheduled” areas classed as sites of special scientific interest due to the presence of an old Roman fort.
The works comprised the building a new pumping station with associated large diameter pipework and manholes plus approx. 300 metres of new 400mm dia. pumped rising main. As the final structure was mostly underground one of the first operations was the construction of a 20m x 15m x 10m deep sheet piled cofferdam. A 1500mm dia. overflow pipe had to be maintained through the works at all times.
On line screen chambers had to be reconstructed. This involved an overpumping situation capable of dealing with a flow of 4 cu.metres/sec. Four 300mm dia. and four 200 mm dia. centrifugal pumps were required for this operation.
The finished building is clad with natural stone and extensively landscaped.
One of the more interesting aspects of this project was the refurbishment of the 900 metre long existing tidal outfall. This relining operation was the first such undertaking ever attempted offshore and was completed very successfully. An additional 1050mm dia. outfall pipe was also laid parallel to the existing to give increased capacity.
Key Facts
| Client: | East of Scotland Water |
| Engineer: | |
| Contract Value: | £5,000,000 |
| Duration of works: | May 2000 – September 2001 |