Work has begun on the £20 million installation of seven miles of new pipes to help deliver fresh, clean drinking water to more than 165,000 people in Edinburgh and the Lothians.
A two-way treated water link will be created between Marchbank Water Treatment Works, near Balerno, and Glencorse Water Treatment Works to create a new mains for a more resilient supply of water.
The first cut has been at the foot of the Pentland Hills with an average of 75 metres of pipe to be laid every day.
Construction is mostly taking placing on private land and being carried out by Scottish Water alliance partner Caledonia Water Alliance over the coming months.
Scott Fraser, Scottish Water regional corporate affairs manager, said: “It is exciting to see the start of this essential project to make the water supply for many of our customers more resilient.
“As always, we thank everyone impacted by our works for their patience and understanding.”
The extended network will also have the capacity to link to other existing and future water supplies across parts of the south of Scotland.
The first sections of pipe being laid measure 500mm in width and each weigh one tonne. The bright blue plastic pipe has a cover on both ends to protect the inside of the pipe and these are only taken off just as the pipes are connected by hand. Already the first few hundred metres of pipe has now been installed.
Workers have faced a number of challenges in the area so far including the proximity of parts of the site to overhead power cables.
Part of the pipe line will go near a military training area and practise trenches which date back to the First World War. A watching brief will be in place during work in these areas to ensure any archaeological remains are located and recorded.
Elsewhere a tunnel crossing will also be dug under the A702 Biggar Road near Hillend to avoid major disruption at this busy road when work takes place here next year.
Schools, businesses and residents as well as community groups are being kept updated on the project. Scottish Water said lorries bringing the pipes to the construction areas are travelling on surrounding roads at quieter times of the day and noise and disruption is being kept to a minimum.
The firm has also promised to keep residents, businesses, landowners and land users – including hill walkers – notified of where the work is being carried out and any diversions in place.
The work will allow customers to be supplied from two different locations if necessary.