Senior Mechanical Engineer - Oxford, Oxfordshire

Join Us as a Senior Mechanical Engineer – Shape the Future of Water and Wastewater Infrastructure. Are you ready to make a meaningful, long‑term impact on communities and the environment? As a Senior Mechanical Engineer at Thames Water, you’ll play a vital role in transforming and modernising our sewage treatment works. Your technical expertise will help deliver innovative, resilient, and cost‑effective engineering solutions that protect public health, safeguard ecosystems, and enable sustainable growth across our region.

In this influential position, you’ll work closely with contractors and multidisciplinary teams to ensure our designs meet the highest standards of technical quality and compliance. You’ll be empowered to lead the assurance of complex engineering projects—bringing excellence to every stage while contributing to a cleaner, greener future for millions of customers.

What you’ll be doing as a Senior Mechanical Engineer:

• Collaborating with a wide range of internal stakeholders—including engineers, asset managers, and operations teams—to develop fit‑for‑purpose, resilient engineering solutions that balance innovation, value for money, and long‑term performance.
• Providing robust assurance and technical oversight of consultants and contractors delivering large and complex capital projects.
• Ensuring compliance with legislation, regulations, and Thames Water standards so that all solutions are delivered safely and meet the technical and environmental requirements set out in the Project Brief.
• Playing a key role in supporting Thames Water’s ‘Triple Zero’ Health, Safety and Wellbeing vision by conducting audits and reviewing Risk Assessments, Method Statements and Safe Systems of Work.
• Identifying, managing, and escalating delivery risks and opportunities throughout the project lifecycle.
• Supporting the production of Project Briefs and providing timely and accurate responses to RFIs.

Location - This role is hybrid, based at Clearwater Court, with travel to Oxford Sewage Treatment Works. You’ll typically spend 2 to 3 days per week on site to support design reviews, assurance activities, and project delivery. 36 hours per week, Monday to Friday.

What you should bring to the role:

• A degree in Mechanical Engineering (or equivalent).
• Experience working in a design and construction‑related engineering role.
• Awareness of applying Construction (Design and Management) Regulations 2015 (CDM 2015).

Nice-to-haves that would make you stand out:

• Strong technical knowledge of pumping systems and mechanical package plant.
• Experience collaborating across multiple engineering disciplines to deliver fully integrated, operational solutions.

What’s in it for you?

• Competitive salary from £55,000 to £65,000 per annum, depending on skills and experience.
• 26 days holiday per year, increasing to 30 with the length of service (Plus bank holidays).
• Generous Pension Scheme through AON.
• Access to lots of benefits to help you take care of you and your family’s health and wellbeing, and your finances.
• Performance-related pay plan directly linked to company performance measures and targets.

Who are we? We’re the UK’s largest water and wastewater company, with more than 16 million customers relying on us every day to supply water for their taps and toilets. We want to build a better future for all, helping our customers, communities, people, and the planet to thrive.

Working at Thames Water is a unique, rewarding, and diverse place to work, where every day you can make a difference, yet no day is the same. If you’re looking for a sustainable and successful career where you can make a daily difference to millions of people’s lives while helping to protect the world of water for future generations, we’ll be here to support you every step of the way.

We’re committed to being a great, diverse, and inclusive place to work. We welcome applications from everyone and want to ensure you feel supported throughout the recruitment process. If you need any adjustments, whether that’s extra time, accessible formats, or anything else just let us know, we’re here to help and support.

When a crisis happens, we all rally around to support our customers. As part of Team Thames, you’ll have the opportunity to sign up to support our customers on the frontline as an ambassador. Full training will be given for what is undoubtedly an incredibly rewarding experience.

Disclaimer: due to the high volume of applications we receive, we may close the advert earlier than the advertised date, so we encourage you to apply as soon as possible to avoid disappointment.