Assistant Process Design Engineer - Water​/Wastewater

Final date to receive applications: 27 November 2026

Department: Process

Employment Type: Permanent
- Full Time

Location: Southampton

Reporting To: Robert Reeves

Join Trant Engineering and help shape the delivery of complex, high-impact projects.

Trant Engineering is a leading EPC contractor with a strong reputation for delivering innovative engineering solutions across the UK and internationally. With over 1,000 employees and a £150m turnover, we're growing and looking to strengthen our Engineering Team with the appointment of an Assistant Process Design Engineer.

The Role

As an Assistant Process Design Engineer
, you will join our multidisciplinary Innovation, Design & Solutions (IDS) team, supporting the design and delivery of projects across the UK water sector. Working alongside experienced engineers, you will develop your technical knowledge and contribute to the successful delivery of water and wastewater treatment projects from feasibility through to detailed design and construction support.

The role will involve working on projects including:

• Water treatment
• Water distribution and storage
• Wastewater treatment and recycling

IDS, Trant's in-house design team, plays a key role throughout the project lifecycle and provides technical expertise across the wider business.

• Support the Engineering Manager and Process Design Manager in delivering process engineering solutions across Trant's UK Water Industry Frameworks.
• Assist with the coordination and integration of process design activities within multi-disciplinary engineering teams.
• Develop an understanding of client requirements and project specifications, producing fit-for-purpose engineering solutions.
• Undertake process design calculations, including mass balances and related engineering assessments.
• Assist in producing process flow diagrams (PFDs), P&IDs and supporting design documentation.
• Contribute to the development of technical reports and process control philosophies.
• Support installation and commissioning activities through the provision of technical guidance where required.

• Build and maintain knowledge of water and wastewater treatment processes and associated technologies.
• Keep up to date with industry developments, standards and emerging engineering solutions.
• Work towards taking ownership of specific process design tasks and project deliverables.
• Participate in continuous professional development activities and professional institution progression.

• Work collaboratively with civil, mechanical, electrical and ICA engineers to deliver integrated design solutions.
• Communicate technical information clearly to colleagues, clients and project stakeholders.
• Support the resolution of technical challenges through analytical problem solving and teamwork.
• Assist with design reviews and interdisciplinary coordination activities.

Uphold and promote the Company's Core Values –
Care, Trust, Respect and Sustainability.

• IChemE accredited MEng, BEng (Hons) or BSc degree in Chemical, Process or a related Engineering discipline.
• Strong technical aptitude and enthusiasm for process engineering.
• Proficient in Microsoft Office applications.
• Excellent communication and teamwork skills.
• Commitment to continuous professional development.

• Previous experience within the water and/or wastewater sector through placements, projects or employment.
• Working towards membership of a relevant professional institution.
• Experience of process calculations and process design documentation.
• Familiarity with process modelling and CAD software.
• Knowledge of UK water industry standards and practices.

At Trant Engineering, we deliver complex, high-value engineering and…