Principal Mechanical Engineer - Water & Wastewater Systems

JN Bentley; West of England; On-site; GBP 90,000 - 120,000; Full time

Benefits offered by this job

Pension contributions 4.5–7%

Employee ownership shares

Annual professional subscription paid

33 days holiday per year

Private medical insurance

Flexible working

Job summary

Mott MacDonald Bentley is seeking a Principal Mechanical Engineer to lead mechanical design on water and wastewater projects. You will drive technical delivery, mentor engineers, and ensure high standards while coordinating with electrical, civil, geotechnical, and process teams.

You will apply client asset standards, manage design tasks to meet deadlines, and collaborate with commercial and construction teams to deliver safe, practical solutions across all design stages.

Qualifications

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

Responsibilities

• Lead and oversee the design, planning, and execution of the mechanical engineering aspects of projects.
• Provide technical expertise and guidance to mechanical engineers and project teams, fostering knowledge and excellence within the team.
• Mentor and develop junior engineers and team members.
• Lead the development of mechanical designs for water and wastewater infrastructure and non‑infrastructure projects, including P&IDs, valve schedules, pumps, tanks, process equipment, above‑ground pipework, lifting and access steelwork.
• Coordinate with the wider design team of electrical, civil, geotechnical, and process engineers.
• Work closely with project teams to ensure application of client asset standards, and engage in technical discussions on best practice and standards waivers.
• Collaborate with commercial, operational, and construction teams to develop efficient, practical, and safe solutions throughout design stages and beyond.
• Positively engage with clients, managing relationships and adopting a one‑team approach to support them in achieving their aims.

Skills

Leadership

Project management

Communication

Problem solving

Mentoring

Education

Chartered Mechanical Engineer

Degree in Mechanical Engineering

Tools

P&IDs

Valve schedules

Job description

Mott MacDonald Bentley is seeking a Principal Mechanical Engineer to lead mechanical design on water and wastewater projects. You will drive technical delivery, mentor engineers, and ensure high standards while coordinating with electrical, civil, geotechnical, and process teams.

You will apply client asset standards, manage design tasks to meet deadlines, and collaborate with commercial and construction teams to deliver safe, practical solutions across all design stages.