Kier has been appointed to deliver a £29m ($39.4m) package of design, development and early works ahead of a proposed advanced anaerobic digestion facility at Blackburn Wastewater Treatment Works in Lancashire, UK.
The wider upgrade would be worth around £170m ($231m) if approved.
The contractor secured the work through United Utilities' Enterprise, a model that combines the teams operating, designing and building the water company's assets with specialist suppliers, allowing schemes to be shaped jointly at an early stage.
Kier's scope covers design development, ground investigations, surveys, enabling activity and site preparation, which is already underway.
While the Enterprise team works on the project solution, programme and delivery strategy, United Utilities is taking the scheme through planning and approval processes.
The scope and timing of any construction phase will be confirmed once planning permission and final project approval are granted.
If it proceeds, the facility would treat an average of around 45,000tpa of dry solids, with additional capacity for seasonal demand, population growth and outages elsewhere in the network.
The proposed design features a new thermal hydrolysis and advanced anaerobic digestion plant, producing an enhanced biosolids product. It is intended to lift renewable biogas output by 20% against the conventional anaerobic digestion process used at the site.
Annual production is projected at around 127GWh of renewable biogas energy.
Kier Infrastructure Water managing director Andy Lingham said: “Blackburn is an important investment in the future resilience of United Utilities’ bioresources network, and we are pleased to be progressing the current programme through United Utilities’ Enterprise.
“By bringing operational, design, construction and specialist expertise together from the outset, the Enterprise can make better-informed decisions and develop a solution around the long-term needs of the site.”
United Utilities already runs the same technology at Davyhulme in Manchester, its largest wastewater treatment site, generating renewable electricity and biomethane.
The Blackburn works treats over 168 million litres of sewage a year, and the scheme sits within the company's target of net-zero greenhouse gas emissions by 2050.
United Utilities Bioresources and Green Energy director Tom Lissett said: “The facility at Blackburn will allow us to increase our renewable energy production and is an important step forward on our journey to net zero.
“The scheme is designed to deliver benefits now and enable us to deliver future innovations to increase biogas production and capture CO₂ when new technologies become more readily available.”
The phased upgrade is expected to finish in mid-2029, with main construction anticipated from mid-2026.
Demolition of 31 outdated processing structures is underway, and a planning application is being prepared for replacement facilities within the site’s existing footprint. The treatment works will remain operational throughout.
