Costain has appointed Peter Mumford as managing director for its natural resources division.

He will join Costain’s executive board and will start on 2 January 2026.

Mumford  will be responsible for furthering the growth of Costain’s successful natural resources division and deliver infrastructure services across its chosen key markets of water, energy and defence.

With more than 20 years’ experience in complex engineering, programme management and consultancy environments, he brings a wealth of expertise in building and leading high-performing teams across the private and public sector.

He joins Costain from Balfour Beatty where he was managing director of its regional civils business in the UK.

Prior to this, he spent five years at Highways England leading the delivery of the government’s £27bn road investment strategy. Before then, Mumford spent more than 15 years in engineering and construction consultancy businesses, including AECOM, EC Harris and Turner and Townsend.

Alex Vaughan, chief executive at Costain, said: “Our natural resources division continues to grow from strength-to-strength and is delivering predictable, best-in-class infrastructure services to our customers in the nationally critical markets of water, energy and defence.

“I’m looking forward to Peter bringing his broad and deep leadership experience so that we can continue to deliver infrastructure for a more prosperous, resilient and decarbonised future.”

Peter Mumford added: “Costain’s reputation and heritage is second to none. I’m excited to be joining the company at this time and adding to its excellent track record in delivering complex and essential infrastructure in the water, energy and defence markets.

 “I am looking forward to accelerating Costain’s growth through our strategy of developing long-term strategic partnerships with tier one customers, broadening our service offering, and remaining an attractive and trusted contractor to our supply chain partners.”

Costain’s natural resources division reported a 7.3% growth in divisional revenue in its recent HY25 results. In recent months, Costain has won a number of significant contracts in its natural resources division, including a £1bn, 15-year contract to deliver utilities infrastructure upgrades at Sellafield and decommissioning work at Trawsfynydd nuclear power station in North Wales. It also recently secured a five-year extension with EDF to deliver project controls services across the UK.