Swift Action and Sustainable Innovation Restore Trinity Road After Sewer Collapse
In 2024, Mackenzie Construction completed an impressive emergency repair project at Trinity Road in Edinburgh, working in collaboration with Scottish Water. What began as a suspected sewer collapse that caused a sinkhole quickly transformed into a case study in efficiency, sustainability, and expert problem-solving.
On 14 August 2024, Mackenzie Construction was called to respond to a sudden sinkhole on Trinity Road. The team quickly mobilised, setting up the site and launching an extensive investigation to assess the situation. Using advanced ground-penetrating radar (GPR) and CCTV surveys, the team discovered a severely blocked sewer line, unusual pipe gradients, and a deep subsurface void – but no actual pipe collapse.
By clearing the debris and conducting precision surveys, Mackenzie Construction ensured the safety of the site before installing a trench box system to access the pipe. Rather than undertake extensive excavation, the team opted for a more sustainable patch-lining repair technique to correct joint misalignments within the 36m pipe. This approach reduced both time on site and carbon emissions.
In another innovative step, a 6-metre-deep underground void was stabilised using a resin/grout injection system—avoiding the need for further excavation, limiting disruption to the community, and delivering a faster, greener solution.
The road was resurfaced and reopened to residents, but the story didn’t end there. During their time on site, Mackenzie Construction identified a separate issue, a sunken area at the Trinity Road and Lennox Row junction. Further investigation confirmed another sewer collapse approximately 3 meters underground.
Employing vacuum excavation to safely navigate around multiple live services—such as gas and water—the team located and repaired the damaged section. Once again, CCTV was used to inspect surrounding areas, and further damage was remedied through patch-lining, avoiding the need to expand the excavation.
By collaborating with utility providers, safely managing complex service infrastructure, and adopting innovative low-carbon repair methods, Mackenzie Construction successfully completed both phases of work on schedule and with minimal impact on local residents.
This project not only highlights the value of rapid response and engineering expertise but also showcases how thoughtful planning and sustainable practices can deliver high-impact solutions with lasting community benefits.
A tenant in the area reached out to Mackenzie Construction during the works to comment on the emergency repair, “For the last few months, you have been carrying out repairs outside my property in Edinburgh on Trinity Road, fixing a burst sewage pipe. I just want to leave a note for your staff, they were really helpful and courteous at a time which understandably was quite frustrating for those of us who didn’t have road access to our houses.”