AFTER 120 days and over 2,800 hours of work, a 23-tonne boring machine named Sandy has finally completed its 270-metre tunnelling journey beneath the M65.

The quest 16 metres underneath the busy motorway began on July 27 and, using laser guiding and GPS location technology, Sandy’s support team managed to construct the tunnel to millimetre accuracy.

Kevin Moody, programme manager at United Utilities, which is responsible for the project, said: “This is an exciting milestone in the mammoth Blackburn and Darwen sewer upgrade infrastructure project.

“Constructing a tunnel under a motorway safely and to absolute precision is no mean feat. However, Sandy and our specialist engineers have worked wonders.

“We have now completed approximately 70 per cent of the new 1.6km pipeline route, so we still have more work to do. But now the tunnel is complete, we can connect the pipeline between Blackburn and Darwen, which is key to this project.”

The pipeline forms part of a £150million project aimed at improving local watercourses that are tributaries of the River Darwen, which feeds into the River Ribble. The improvements will ultimately have environmental benefits by helping to continue the improvement of water along the Fylde coast.

Part of the project includes the installation of a revolutionary wastewater treatment technology at Blackburn wastewater treatment works, known as Nereda®.

Blackburn will have the largest purpose-built Nereda® process plant in Europe, built within the current wastewater treatment site boundary. We were the first in the UK to invest in a pilot plant for Nereda® and we’ve been hard at work testing the process at a number of our sites."

He said the new technology represented a significant and evolutionary step in wastewater treatment technology.

The project will be fully operational in 2021.