Scottish Water’s £100m deep tunnel sewer progresses
Publicly-owned utility Scottish Water is now more than half way through what will be the biggest investment in the Greater Glasgow area’s wastewater infrastructure in more than a century...
Publicly-owned utilityScottish Water is now more than half way through what will be the biggest investment in the Greater Glasgow area’s wastewater infrastructure in more than a century.
The £250 million, five-year programme of work to improve river water quality and the natural environment of the River Clyde started in early 2013.
The investment follows collaboration and studies by the Metropolitan Glasgow Strategic Drainage Partnership (MGSDP), whose members include Scottish Water, the Scottish Environment Protection Agency (SEPA), Glasgow City Council and Scottish Canals.
The improvements are required to meet European directives and SEPA recommendations and will contribute towards the Scottish Government’s objective to comply with the Urban Waste Water Treatment Directive.
This is as well as achieve Water Framework Directive ‘good ecological status’ or ‘good ecological potential’ for more than 40 miles of the River Clyde and its tributaries.
Scottish Water’s investment includes upgrades to about 200 Combined Sewer Overflows (CSOs) or outfall pipes – safety valves used to control wastewater during heavy rainfall - on the River Clyde and tributaries such as the River Kelvin and White Cart Water at a cost of about £105 million.
A total of 128 of some 222 CSOs dotted across the Greater Glasgow area have been completed.
The investment also includes a number of key projects to tackle flooding at a cost of about £45 million and wastewater improvements in the south west of Glasgow to remove excess surface water from areas with known “pinchpoints” which cause restrictions in the system.
The flooding investment includes completed projects such as improvements to sewer capacity in the Shettleston area of Glasgow, which has reduced the risk of flooding in Strowan Crescent, and a project to tackle flooding which has affected more than 60 properties in the Shafton Road area of Temple in Glasgow.
The value of investment already completed is about £100 million or 40% of the total £250 million in the five-year programme.
At the very centre of Scottish Water’s improvements is a £100 million wastewatertunnel called the Shieldhall Tunnel, the biggest single project in the programme.
The tunnel will resolve large-scale water quality problems in the River Clyde and its tributaries and provide aesthetic screening to overflows into watercourses such as tributaries of the Clyde and White Cart Water. In short, it will increase capacity and alleviate pressure on the existing network by providing additional stormwater storage.
It will be built using a tunnel boring machine (TBM), which will followa route from the Queen’s Park area towards Pollok Park.
The tunnel will be 3.1 miles long - more than five times as long as the Clyde Tunnel - and 4.65m in diameter.
The team involved in the Shieldhall Tunnel for Scottish Water, known as the Glasgow Tunnel Partnership, is a commercial joint venture between Costain and VINCI Construction Grands Projets (correct) called CVJV, with additional local partners George Leslie and AECOM. Technical support is being provided by CH2M.
CVJV’s preparatory work is expected to be completed in the spring of 2016, after which the tunnelling proper will begin. The Shieldhall Tunnel is expected to be completed by about the end of 2017.