Slessor will start in his new role in January following a 17-year career at Galliford Try

He led the merger of GT water with nmcn, creating the largest single contractor to the UK water sector in 2021.

RSE recently announced investment from London-based equity partners MML and has ambitious expansion plans.

Current CEO Iain MacGregor will remain an executive director at RSE and a significant shareholder in the Group.

MacGregor said:  “I am delighted to be welcoming Stephen into the RSE family at such an exciting time.  We have enjoyed considerable growth in the last four years, turning a £60m service company in Scotland to a £250m+ technical specialist that services clients in the water sector across the UK.

“Demand for innovation to meet the needs of the water sector is positioning RSE for further growth. We believe that bringing Stephen’s skills, experience and energy into the business will help guide RSE with our growth plans and realise the full potential of our modular solutions across UK and International markets.”

Slessor added: “I’m thankful to GT for the opportunity afforded me in my previous role.

“It’s an exciting time to be joining RSE and it fulfils my entrepreneurial aspirations to build something unique and game changing in the water sector – a true disruptor. RSE’s differentiated technical offering, including its modular approach to water treatment, will shape the future of the sector in the UK and abroad.

“I’m pleased to now be part of this and look forward to working with my new colleagues when I join in January.”

Galliford Try has promoted Mark Shadrick to the role of managing director of its Environment division.