The first phase of a huge multi-million investment to upgrade a sewer main between Renfrew and Glasgow is almost complete.

Scottish Water has announced the starting works of a more than £10million investment to upgrade a strategic rising sewer main between the Renfrewshire town and the city are nearly finished.

Earlier this year, engineers set up a temporary overland pipeline to carry the pressurised flows of wastewater while the existing underground pipe was relined.

READ MORE: Multi-million-pound sewer project set to begin in Renfrew

Now, the firm says over 800 metres of sewer rising main have been successfully upgraded and final pressure testing is underway.

Meanwhile, the water company says the project has been fast-tracked following a spate of bursts.

The first phase on King’s Inch Road deals with the most burst-prone section while further phases to upgrade the upstream sections will be progressed over the coming months.

(Image: Supplied)

Scottish Water Alliance Manager Robert Archer said: “Once the pressure testing has been successfully completed, new segments of pipe will be installed at each of the six openings that were made to reline the existing pipe.

“Flows will then be transferred from the overland temporary pipe to the newly lined underground rising main and the bypass pipe will be removed and the areas reinstated.”

(Image: Supplied)

Robert Archer added: “This is a tried and tested method to deliver the resilience required as quickly as possible with as little disruption as possible and we are grateful to everyone affected for their patience and cooperation.

“Scottish Water is investing huge sums - over £2.5billion in the past 10 years – on similar projects across the country to tackle the challenges of ageing infrastructure, climate change and increasing demand.”

The project is being delivered by Caledonia Water Alliance and other specialist contractors.

The first phase is expected to be completed by November 2024.