Senior Mechanical Design Engineer - Water Salary: �50,000 - �60,000 Location: Hemel Hempstead Contract: Permanent, Full Time Hours: 40 hours per week The Role We are seeking an experienced Senior Mechanical Design Engineer to play a key technical leadership role within a growing design team, delivering mechanical engineering solutions across a diverse portfolio of water and wastewater treatment projects. You will take ownership of the full mechanical design lifecycle - from concept development through to project completion - ensuring all solutions meet regulatory, safety, environmental, and client requirements. Working closely with multidisciplinary teams, you will support the delivery of fully integrated designs, carry out technical reviews and risk assessments, and provide specialist input during procurement, installation, and commissioning. In addition, you will act as a mentor to junior engineers, helping to build technical capability while promoting innovation, quality, and best practice across the team. This role is based in Hemel Hempstead, with a requirement to attend the office or project sites at least three days per week. About the Organisation The business operates within the UK water and civil engineering sectors, delivering vital infrastructure that supports clean water, safe drainage, and resilient wastewater services. With specialist expertise across mechanical, electrical, instrumentation, control and automation systems, the organisation delivers solutions ranging from individual equipment supply through to full system integration and commissioning. Teams work collaboratively to solve complex engineering challenges, with a strong focus on safety, sustainability, and technical excellence. What We're Looking For We are looking for a technically capable and forward-thinking engineer who can confidently lead mechanical design packages, support and develop others, and represent the discipline to clients and stakeholders. Experience 7-10 years' experience in mechanical design engineering, ideally within the water or wastewater sector Proven experience delivering mechanical designs for treatment or infrastructure projects within multidisciplinary teams Strong understanding of mechanical equipment used in water treatment, including pumps, pipework, valves, blowers, and filtration systems Solid knowledge of mechanical design standards, HSE requirements, and environmental regulations Experience supporting commissioning, troubleshooting, and optimisation of mechanical systems Knowledge & Skills Strong leadership and mentoring skills, with experience guiding engineers and graduates Excellent problem-solving ability and a track record of delivering efficient, cost-effective design solutions Highly organised, with the ability to manage multiple projects while maintaining quality and accuracy Confident communicator, able to explain technical information clearly to both technical and non-technical stakeholders Collaborative approach and ability to work effectively across engineering disciplines Qualifications Bachelor's degree in Mechanical Engineering or a related discipline Chartered Engineer (CEng) status, or actively working towards chartership Proficiency in mechanical design tools such as AutoCAD, SolidWorks, or similar software Why Apply This is an excellent opportunity to take a senior role in designing mechanical systems that supp