Principal Mechanical Engineer - Water​/Wastewater

About the Role

The UK water sector is entering a period of unprecedented investment and transformation. As Egis accelerates the growth of its Water Business in the UK, we are building a high-performing Mechanical Engineering team to help shape this next chapter.

We are inviting applicants who want to play a meaningful role in delivering major water and wastewater programmes in the UK. Working within a collaborative, multidisciplinary environment, you will contribute to technically robust, sustainable and innovative treatment solutions across nationally significant projects.

This is a rare opportunity to join at a key stage of our UK growth journey, helping to establish, shape and expand a Mechanical engineering capability built on Egis' global infrastructure expertise and long-term commitment to the sector.

• Lead mechanical design delivery on multidisciplinary water/wastewater treatment projects across the full design lifecycle.
• Act as mechanical technical lead on projects, owning design strategy, key decisions, interfaces, risks and quality of deliverables.
• Review and approve mechanical calculations, specifications, datasheets, reports, P&IDs, layouts, schedules, drawings and supplier/contractor submissions.
• Lead equipment selection and mechanical design for pumps, pipework, valves, tanks, lifting systems, packaged plant, treatment equipment and associated process systems.
• Lead mechanical input to optioneering, value engineering, design reviews, HAZOP/SWIFT, constructability, maintainability and commissioning reviews.
• Drive multidisciplinary coordination across Process, EICA, civil/structural, architectural, MEP, construction and operations teams.
• Promote lean and digitally enabled delivery through standardised tools, BIM/3D coordination, hydraulic analysis, data-led design and reusable templates.
• Provide technical assurance and support project managers with technical risk, scope, resourcing, programme and change control.
• Mentor and manage engineers where appropriate, supporting recruitment, development and chartership progression.
• Contribute to bids, client engagement, opportunity shaping and growth of the mechanical capability.

• BEng/MEng or equivalent in Mechanical Engineering.
• Chartered Engineer or Incorporated Engineer status with a relevant professional institution, such as IMechE.
• Typically 8-10+ years' relevant mechanical engineering design experience.
• Background must be from water, wastewater, biosolids/bioresources or oil & gas.
• Proven ability to act as mechanical discipline lead or senior technical lead on multidisciplinary projects.
• Strong technical expertise in mechanical treatment/process systems, including equipment selection, pumping, pipework, valves, hydraulics, layouts and packaged plant.
• Strong understanding of UK water industry standards, CDM 2015, safety-by-design, regulatory drivers and common delivery models.
• Ability to coordinate multidisciplinary interfaces and resolve complex mechanical design issues.
• Strong digital mindset, with experience applying modelling, automation, BIM/3D coordination, data analysis or standardised workflows.
• Confident client-facing communicator with experience leading workshops, technical reviews and design discussions.
• Experience mentoring or managing engineers and supporting technical capability development.

• Deep experience in wastewater treatment, clean water treatment, sludge/bioresources, water reuse, pumping stations, chemical dosing, odour control, energy recovery, package plant or complex process systems.
• Experience delivering AMP8, WINEP, SRO, D&B, framework, alliance or contractor-led projects.
• Experience developing mechanical design standards, calculation tools, equipment specifications, QA processes or reusable digital workflows.
• Experience contributing to recruitment, resource planning, bid writing, technical proposals, client presentations or new service development.

Please note that you must have the right to work in the UK to be considered for this position.

• An exciting new growth role in a fast‑organic growing UK business, offering clear and accelerated career progression
• Top Employers 2025 - Egis recognised across four continents for excellence in HR practices, having been awarded the prestigious Top Employer 2025 certification. Top Employers Institute is the global authority on recognising excellence in people practices.
• A global leader in green infrastructure - we're proud to lead the way in sustainable infrastructure, mobility and energy, innovating across the entire value chain and every aspect of the built environment.
• Highly competitive leadership‑level reward package
• Hybrid and flexible working
• 26+ days annual leave plus bank holidays
• Professional development, chartership support & global mobility
• Supportive, inclusive culture driven by sustainability and long‑term community impact

Join Egis and play a pivotal role in shapin