Principal Mechanical Engineer

Mott Mac Donald Bentley is a fully integrated design and build business combining the design expertise of Mott Mac Donald with the contracting experience of JN Bentley to deliver award winning projects. Working for Mott Mac Donald Bentley, you will work on major water and wastewater schemes throughout all phases of the project from feasibility through to construction. With an annual turnover surpassing £600 million, Mott Mac Donald Bentley cements its position as a leader within the industry.

The sustained, robust business performance creates an ideal environment for career growth.

As part of our appointment to Scottish Water’s new Enterprise, we will deliver projects at sites across Scotland. Works will include major upgrades to treatment assets, new and enhanced networks, and resilience schemes that will benefit communities across the country.

25+ years in the water sector

Over successive regulatory periods, MMB has delivered a wide range of complex water and wastewater projects that directly support SR27 priorities, including:

• Enhancing resilience and service reliability through treatment works upgrades, network improvements and resilience schemes
• Supporting net zero and climate adaptation via low‑carbon design, nature‑based solutions and environmental compliance projects
• Enabling sustainable growth by delivering infrastructure that supports new development and protects existing communities
• Driving efficiency and affordability through integrated delivery, innovation and collaborative planning
• Maintaining a strong focus on customers, communities and safety across everything we do

As a Principal Mechanical Engineer, you will contribute to projects that significantly impact our environment and communities. Working primarily in the UK water market, MMB provides the feasibility, design, construction and commissioning services needed to keep water flowing and wastewater treated. You’ll work on projects that make a real difference to our environment and our communities by enhancing the efficiency and effectiveness of water and wastewater treatment systems.

You will play a pivotal role in shaping the mechanical functions throughout the lifecycle of various projects.

• Lead and oversee the design, planning, and execution of the mechanical engineering aspects of our projects.
• Provide technical expertise and guidance to our mechanical engineers and project teams. Develop knowledge and excellence within the team.
• Mentor and develop junior engineers and team members.
• Lead the development of the mechanical design of water and wastewater infrastructure and non‑infrastructure projects through the project lifecycle encompassing P&IDs, valve schedules, pumps, tanks, process equipment, above‑ground pipework, lifting and access steelwork.
• Coordinate with the wider design team of Electrical, Civil, Geotech and Process engineers.
• Work closely with the project teams to ensure applications of client’s asset standards and engage in particular technical discussions on best practice and standards waivers.
• Working closely and collaboratively with the commercial, operational and construction teams to develop efficient, practical and safe solutions throughout design stages, construction and beyond.
• Positively engage with the client, managing relationships and adopting a one‑team approach to supporting them in achieving their aims.

• Chartered Mechanical Engineer or above
• Degree in Mechanical Engineering, or related field
• Strong knowledge of the water and/or wastewater industry
• Strong knowledge of mechanical engineering principles, practices, and standards relating to process industries
• Excellent communication, leadership and problem‑solving skills
• Proven ability to manage multiple design tasks and meet deadlines

Financial wellbeing

• MMB match employee pension contributions between 4.5% and 7%.
• As an independently owned business we share the financial success of the business with all our colleagues including our annual bonus schemes.
• Payment of annual professional institution subscription costs.

• A minimum of 33 days holiday each year,…