Senior​/Principal Mechanical Engineer

Water & Wastewater Infrastructure
Location: St Albans
Employment Type: Permanent

Our client is seeking an experienced Senior Mechanical Design Engineer to join their growing engineering team delivering major water and wastewater infrastructure projects. This is an excellent opportunity for a technically strong engineer with extensive design experience in the water sector to take ownership of complex mechanical design packages, mentor junior engineers, and contribute to the successful delivery of high-profile projects.

The successful candidate will play a key role in the development, coordination, and delivery of mechanical engineering designs, ensuring compliance with industry standards, client requirements, and project objectives.

• Produce high-quality mechanical design deliverables that meet safety, quality, and regulatory requirements.
• Develop mechanical designs, calculations, drawings, reports, and technical specifications for water and wastewater projects.
• Undertake hydraulic design and analysis for a range of treatment and infrastructure schemes.
• Lead and mentor CAD technicians, graduate engineers, and junior design staff.
• Prepare scopes of work for subcontracted M&E design teams and review their outputs for technical accuracy and compliance.
• Liaise with equipment suppliers, manufacturers, contractors, and project stakeholders throughout the design process.
• Ensure all designs comply with relevant industry standards, professional guidelines, and company procedures.
• Manage and record design changes throughout the project lifecycle.
• Estimate design hours and support project planning and resource allocation.
• Attend and present at design reviews, client meetings, technical workshops, and project presentations.
• Collaborate with multidisciplinary engineering teams to deliver integrated design solutions.

• Minimum 10 years' mechanical design experience within the water industry.
• Significant experience in hydraulic design and water sector engineering projects.
• Awareness and understanding of electrical design principles and control systems.
• Degree-qualified or HND-qualified in Mechanical Engineering or a related discipline.
• Strong IT skills, including engineering design software and Microsoft Office applications.
• Membership of a recognised professional engineering institution and actively working towards professional chartership.

• Chartered Engineer (CEng) status.
• Experience in electrical engineering and/or control systems engineering.
• Proven experience across both clean water and wastewater treatment projects.
• Good understanding of construction methods, installation practices, and engineering materials.
• Strong knowledge of engineering drawing standards and best practices.

• Mechanical engineering design
• Hydraulic calculations and analysis
• Engineering specifications and technical reporting
• Design review and quality assurance
• Multidisciplinary engineering coordination
• Water and wastewater treatment processes

• Excellent communication and stakeholder management skills
• Strong problem-solving and analytical abilities
• Results-driven and delivery-focused approach
• Ability to lead, mentor, and develop junior team members
• Strong attention to detail and commitment to quality
• Effective planning, organisation, and time management skills

The ideal candidate will be a proactive and technically capable Senior Mechanical Design Engineer who can lead design activities from concept through to detailed design and delivery. You will have a collaborative approach, strong commercial awareness, and the ability to provide technical leadership while supporting the development of less experienced engineers.

If you are looking to join a forward-thinking engineering organisation delivering essential water infrastructure projects, we would be keen to hear from you.