Senior Mechanical Design Engineer

As part of the United Infrastructure Group, we are a dynamic and innovative specialist engineering services, solutions and products provider focused on servicing our clients’ immediate and future needs. We do this through the development of industry-changing cleantech products as well as through engineering delivery excellence.

We specialise in the design and delivery of process, mechanical, electrical and ICA engineering-based projects, products and solutions. Regardless of the project, they all pursue the same goal: to improve the efficiency and sustainability of our water, wastewater and waste treatment.

We have a team of highly skilled and experienced professionals with extensive consulting and contracting experience, including engineers, scientists and commercial managers. Our knowledge and expertise spans more than 30 years, across industries including: water, wastewater, marine, energy and power sectors. At AFECO, we cover all stages of the innovation and project delivery cycle from concept through to operations.

Our aim is simple – to provide the most effective solutions and products on the market and thus, exceed clients expectations through market-leading technology. From technical through to commercial and management expertise, we have the in-house expertise to execute a range of projects from the most basic to highly complex.

About us

AFECO is an engineering services provider, delivering high quality process and MEICA design and installation projects predominantly across the South of England and Midlands for the water industry. We have excellent inhouse engineering teams capable of delivering all stages of the project cycle, from concept through to commissioning, with a strong focus on process led innovative and robust yet appropriate solutions.

We have a portfolio of varied projects covering both wastewater and clean water projects for planned and reactive projects. Due to the expansion of our team, we are currently recruiting for a Senior Mechanical Design Engineer to work within our multi-disciplinary teams. This is a great opportunity for enthusiastic individuals who fit in with our company values and are keen to develop in a forward-thinking organisation.

Role Purpose

The Senior Mechanical Design Engineer will lead the mechanical design of water and wastewater treatment assets across the project lifecycle, from concept and detailed design through to construction support and commissioning. The role requires strong technical capability, sound engineering judgement, and the ability to mentor junior engineers while working collaboratively with multi-disciplinary teams.

Key Responsibilities

• Technical Design & Delivery
  • Lead mechanical design activities for water and wastewater treatment projects, including pumping stations, treatment works, pipelines, and associated infrastructure.
  • Produce and review mechanical designs, calculations, specifications, schedules, and drawings.
  • Ensure designs comply with relevant standards, legislation, client specifications, and health & safety requirements.
  • Undertake optioneering and value engineering to balance cost, performance, risk, and operability.
  • Support constructability, commissioning, and handover activities.
• Equipment & Systems
  • Specify, size, and select mechanical equipment such as pumps, valves, screens, blowers, mixers, and mechanical treatment processes.
  • Review supplier technical submissions and manage technical interfaces with vendors.
  • Assess whole-life cost, reliability, and maintainability of mechanical systems.
• Project & Stakeholder Interface
  • Work closely with process, civil, electrical, and ICA engineers to deliver integrated solutions.
  • Liaise with clients, contractors, suppliers, and operations teams.
  • Provide technical input during design reviews, HAZID/HAZOP, and risk workshops.
• Mentorship & Quality
  • Mentor and technically support graduate and intermediate engineers.
  • Review and approve work produced by others.
  • Contribute to the development of internal standards, best practices, and lessons learned.

Qualifications & Experience

• Essential
  • Degree (or equivalent) in Mechanical Engineering.
  • Significant experience in the water or wastewater sector.
  • Strong knowledge of mechanical equipment used in water treatment and conveyance.
  • Experience delivering designs through concept, detailed design, and construction stages.
  • Familiarity with relevant standards (e.g. ISO, BS, EN, WIMES, client standards).
• Desirable
  • Experience working on regulated water frameworks.
  • Site experience including commissioning or construction support.
  • Knowledge of asset management and whole-life cost analysis.
  • Experience with NEC or other engineering contracts.

Technical Skills

• Mechanical design and specification.
• Pumping system design and hydraulics (desirable).
• Design risk assessment and CDM compliance.
• 2D/3D CAD tools (e.g. AutoCAD, SolidWorks).
• Engineering calculations and reports.

Salary and benefits

• Medicash plan.
• Life insurance.
• Benefits portal.
• Company pension.
• 25 days holiday (plus bank holidays).

At AFECO, we value our employees and encourage and support them to develop themselves and their career through training and progression. We offer the opportunity to work on a range of project types and sizes in the water sector including our own internally developed products and solutions. We are a privately owned business with a friendly and open culture and are dedicated to creating and maintaining a workforce that is highly skilled and motivated. As a company, we are committed to equal opportunities for all and do not discriminate on the grounds of race, religion or belief, sexual orientation, gender reassignment, marital or civil partner status, sex, disability or age.

Join us at AFECO and be part of our mission to deliver innovative and sustainable solutions to the complex infrastructure needs of the UK.