A 40-ton machine called Lily has just surfaced at the edge of Knutsford after spending weeks underground. The tunnel boring machine has completed the first part of a major sewer project without requiring the town to be opened up along the entire route. That quiet approach is the real story: instead of digging a long trench through a busy community, engineers are putting the new stormwater infrastructure beneath it.
Lily broke through at Knutsford Wastewater Treatment Works on Aug. 12, completing the first drive of United Utilities’ £48 million upgrade. The full tunnel will stretch about 1.8 kilometers, or 1.1 miles, between the Moor Pumping Station and the treatment works. At its deepest point, it will sit nearly 20 meters, or about 66 feet, below ground.
