Alarge, yellow crawler crane is in position, poised over a concrete shaft at the pie-shaped worksite near Fairy Lake in Newmarket, Ont.

Nearby, an excavator operator is loading dirt onto a waiting dump truck.Nothing out of the ordinary for your typical construction site, really.Roughly 12 metres below ground, though, it’s a different story. A cigar-shaped, micro-tunnel boring machine is ready to go to work.The task?Dig away at the dense underground soil and dirt so concrete pipes can be laid for a 5.1-kilometre-long sewage pipe that will run parallel to an existing 36-year-old forcemain through the heart of Newmarket.

Work on the $110.6-million project, aptly named the York Durham Sewage System Forcemain Twinning Project, is well under way and should be completed by December 2021. The project also includes changes to the Newmarket and Bogart Creek sewage pumping stations to improve the system.