Oxford Sewage Treatment Works is set for a £340 million upgrade after Thames Water’s contractor, Murphy, named AECOM as its exclusive design partner for the project. The scheme will raise treatment capacity by approximately 40%, expand storm tank capacity, and upgrade power supplies to serve Oxfordshire’s growing population.

AECOM will provide multidisciplinary design services under the arrangement, supporting a project aimed at improving effluent quality discharged into the River Thames. The work forms part of Thames Water’s capital delivery program for AMP8, the current five-year UK Asset Management Period that runs the industry’s regulated investment cycle.

Upgrade Targets Growth and Storm Overflow Reduction

David Mayfield, senior project manager at Thames Water, said the upgrade represents a long-term investment in the resilience of the utility’s wastewater network, adding that the collaboration with AECOM and Murphy is intended to reduce storm overflows while expanding capacity for the region’s communities.

Extends AECOM’s Thames Water Partnership

The appointment extends AECOM’s existing relationship with Thames Water and Murphy. The two firms previously worked together, alongside Kier, on the upgrade of Thames Water’s Deephams Sewage Treatment Works, one of London’s largest wastewater treatment plants.

Beverley Stinson, chief executive of AECOM’s global water business, said the firm’s ranking as the world’s top water design firm by Engineering News-Record positions it to bring AI-enabled design technology to the Oxford project. Richard Whitehead, chief executive of AECOM’s Europe and India region, said the award builds on the company’s established position in the UK water sector.

Part of a Broader UK Water Portfolio

The Oxford win adds to a run of recent UK water contracts for AECOM, which has also secured positions on AMP8 infrastructure frameworks, a roughly $400 million professional services framework with Thames Water, and a $4.8 billion capital delivery program with Southern Water. The project also reflects a wider push across the UK water sector during AMP8 to cut storm overflows and strengthen network resilience — Yorkshire Water’s AMP8 Environmental Investment Programme, running through 2030, is pursuing similar goals through 1,000km of pipe upgrades and AI-powered sewage monitoring.

Fact sheet:

• Project: Oxford Sewage Treatment Works upgrade
• Client: Thames Water
• Contractor: Murphy
• Design partner: AECOM (exclusive, multidisciplinary design services)
• Estimated value: £340 million
• Capacity increase: ~40%
• Program: Thames Water’s AMP8 capital delivery program
• Scope: Increased treatment capacity and flows, expanded storm tank capacity, upgraded power supplies, improved effluent quality
• Prior related work: Deephams Sewage Treatment Works upgrade (AECOM, Murphy, Kier joint venture)