Managing director of Black & Veatch’s Europe water division Tony Collins said the greenfield site at Glencorse had received advanced approval and Black and Veatch were about 30 per cent of the way through the design process.
Mr Collins added the design process was expected to take until the end of 2008 and then Scottish Water and Black & Veatch would need to agree on the target cost.
The water treatment plant will provide water for 500,000 people and is part of Scottish Waters investment strategy to meet European guidelines on drinking water quality.
As well as the plant 8 km of twin pipes will be constructed to move water from the new water treatment works to the existing distribution network in Edinburgh.
Earlier this year, Black & Veatch completed a £120 million water treatment plant at Loch Katrine outside of Glasgow for Scottish Water.
To see a video of the new water site click here