AECOM Selected as Exclusive Design Partner to Support a GBP340 Million Upgrade of Thames Water’s Oxford Sewage Treatment Works in the UK

AECOM will support Thames Water, one of the UK’s largest water and wastewater service providers, to deliver this scheme as part of the AMP8 capital investment programme.

AECOM, one of the trusted global infrastructure leaders, announced that it has been appointed by Murphy as its design partner to deliver Thames Water’s major upgrade of the Oxford Sewage Treatment Works in the UK. With AECOM appointed as the contractor’s exclusive design partner for multidisciplinary design services, the upgrade will increase treatment capacity by approximately 40% while supporting population growth and protect the environment by further improving effluent quality that goes into the River Thames at the end of the sewage treatment cycle.

The upgrade is a key part of Thames Water’s capital deliver works programme during AMP8, the UK’s current Asset Management Period 8 (AMP8). The approximately GBP340 million scheme also includes upgrading power supplies and increasing storm tank capacity and sewage treatment flows.

Upgrading these major sewage treatment works is critical for facilitating growth and protecting the environment for communities in Oxfordshire. AECOM is the world’s number one water design firm as ranked by Engineering News-Record, and we are proud to bring our global technical excellence to support Thames Water in providing a significant increase in treatment capacity. Key to success is harnessing our world-leading technology and AI-enabled solutions to deliver more efficient, resilient and sustainable infrastructure for the future.

Beverley Stinson, Chief Executive of AECOM’s Global Water Business

“AECOM continues to strengthen its position in the UK water market, and we look forward to helping deliver cleaner waterways for communities in Oxfordshire and beyond,” said Richard Whitehead, Chief Executive of AECOM’s Europe and India region. “Building on our proud legacy as a trusted partner to the industry, this award reinforces our longstanding relationship with Thames Water. By continuing our successful collaboration with Murphy, we are bringing together the best skills and expertise to help Thames Water enhance its services for customers.”

“This upgrade to Oxford Sewage Treatment Works represents a significant investment in the long-term resilience and environmental performance of our wastewater network,” said David Mayfield, Senior Project Manager at Thames Water. “By working closely with AECOM and our delivery partner Murphy, we’re ensuring that Oxfordshire’s growing communities benefit from an upgraded, future-ready treatment facility that safeguards our waterways, enhances capacity and provides a resilient wastewater service, with fewer storm overflows for years to come.”

AECOM previously delivered Thames Water’s Deephams Sewage Treatment Works upgrade in a joint venture with Murphy and Kier, which is one of London’s largest wastewater treatment plants. This latest win builds on AECOM’s key wins related to the AMP8 UK water infrastructure framework, including supporting Thames Water’s approximately $540 million professional services framework and Southern Water’s $4.8 billion capital delivery program.

About AECOM  
AECOM is one of the global infrastructure leaders, committed to delivering a better world. As a trusted professional services firm powered by deep technical abilities, it solves our clients’ complex challenges in water, environment, energy, transportation and buildings. Its teams partner with public- and private-sector clients to create innovative, sustainable and resilient solutions throughout the project lifecycle – from advisory, planning, design and engineering to programme and construction management. AECOM is a Fortune 500 firm that had revenue of USD16.1 billion in fiscal year 2025.

Learn more at aecom.com. 

About Thames Water
Thames Water is one of the UK’s biggest water and wastewater services providers. Its key workers provide essential services around the clock to 16 million customers across London, the Thames Valley and surrounding areas. It provides 2.7 billion litres of drinking water and safely removes 4.6 billion litres of wastewater every day. Thames Water invested GBP2.2 billion in 2024/25, and it will continue to spend wisely on improving resilience, service and efficiency, as well as provide more support for customers in vulnerable circumstances. It also has additional responsibilities to society and the natural environment. What it does and how it does it delivers significant public value, which is why Thames Water has ambitious plans to self-generate more of its own power, reduce its carbon emissions and increase biodiversity across its sites.