Senior Mechanical Engineer

Job title Senior Mechanical Engineer  Division Asset Operations & Capital Delivery Location Hybrid - Oxford STW - OX4 4YU
Contract type Permanent Full/Part-time Full-time Salary Competitive salary from £55,000 to £65,000 per annum, depending on skills and experience. Job grade B Closing date 02/02/2026

Join Us as a Senior Technical Assurance Engineer – Shape the Future of Water and Wastewater Infrastructure.

Are you ready to make a lasting impact on communities and the environment? As a Senior Technical Assurance Engineer at Thames Water, you’ll be at the forefront of transforming and modernising our sewage treatment works. Your expertise will drive the delivery of innovative, cost-effective, and resilient engineering solutions that protect public health, preserve ecosystems, and support sustainable growth.

In this pivotal role, you’ll collaborate closely with contractors and multidisciplinary teams to ensure designs meet our rigorous technical standards and quality benchmarks. You’ll be empowered to lead projects that matter—bringing engineering excellence to life while contributing to a cleaner, greener future.

• You'll have the exciting opportunity to collaborate with diverse internal stakeholders, including engineers, asset management, and operations. This collaboration will shape fit-for-purpose solutions and positively influence the balance of innovation, value for money, and resilience.
• This role also requires extensive collaboration with, and assurance of, consultants and contractors who support the delivery of often large and complex capital projects.
• Ensuring compliance with legislation and regulations, as well as our policies, standards, and expectations, so that solutions are delivered safely and meet the technical and environmental requirements of the Project Brief.
• Your role will be crucial in actively supporting Thames Water’s ‘triple zero’ Health, Safety, and well-being vision. By conducting audits and reviewing Risk Assessments, Method Statements, and Safe Systems of Work, you'll help us achieve our goal of zero incidents, zero harm, and zero compromise.
• Identifying and supporting the management of delivery risks and opportunities.
• Contributing to the creation of Project Briefs and responding to RFIs.

• Be educated to a degree level in Mechanical Engineering.
• Background in working in a design and construction-related role.
• Awareness of applying the Construction (Design and Management) Regulations 2015. (CDM 2015)

• Have technical knowledge and expertise of pumping systems
  , mechanical package plantand the ability to work with various engineering disciplines to create fully operational solutions.

• 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 – from annual health MOTs and access to physiotherapy and counselling, to Cycle to Work schemes, shopping vouchers and life assurance.
• Performance-related pay plan directly linked to company performance measures and targets.

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. It’s a big job and we’ve got a long way to go, so we need help from passionate and skilled people, committed to making a difference and getting us to where we want to be in the years and decades to come.

Thames Water is a unique, rewarding, and…