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ICE People's Choice Award

Wolsingham Sewage Treatment Works Growth

Wolsingham, United Kingdom




20 months




United Kingdom
Project achievements

Solved the problem

Increased the site’s capacity in line with future population growth

Environment benefitted

Maintains highest possible standards of environmental protection

Used engineering skill

Used off-site construction methodology

Keeping water flowing and local wildlife thriving

The Wolsingham Sewage Treatment Works (STW) Growth project has increased the site’s capacity in line with future population growth.

It will maintain the highest possible standards of environmental protection in the area, keeping water flowing and local wildlife thriving.

It’s one of the finalists in the ICE People’s Choice Awards in 2022.

It was nominated for having impressive health and safety statistics, improved performance, and having notable productivity gains and related savings.

It achieved improved productivity through:

  • The use of new technology,
  • The implementation of off-site and sustainable construction methods, and
  • Exemplar collaboration and team integration between the client, Northumbrian Water, Tilbury Douglas-Wood delivery team, and the wider supply chain.

Being sustainable and cutting costs

Tilbury Douglas Construction Limited (TDCL) built an offline sewage treatment works using offsite build methodology and sustainable materials.

These have rarely been seen within the water industry.

The new works was designed to fit within the existing Wolsingham sewage treatment work site footprint.

This protected the local environment, as no extra greenfield land was needed.

While the project was originally awarded based on a plan for traditional reinforced concrete structures, TDCL used technology to make significant savings.

Using technology across several parts of the project helped cut time (more than four months) and saved Northumbrian Water nearly £1 million pounds.

This was an even more notable achievement given that the project was delivered throughout the height of the COVID-19 pandemic.

Wolsingham Sewage Treatment Works Growth

A 4D animation of the sewage treatment works.

Image courtesy of Tilbury Douglas Construction Limited

Wolsingham Sewage Treatment Works Growth

Close-up view of the sewage treatment works.

Image courtesy of Tilbury Douglas Construction Limited

Wolsingham Sewage Treatment Works Growth

Bird's-eye view of the new sewage treatment works.

Did you know …

  1. In terms of health and safety, the project reported zero accidents or incidents, with person hours almost halved.

  2. The project was completed 100 days early and £800k below client budget.

  3. The project designed, developed and constructed a new sewage treatment works using fully sustainable materials, with an off-site build mindset.

Difference the project has made

As well as improving the quality of rivers for the benefit of the people and the environment, the project kept sustainability in mind.

Using materials efficiently resulted in zero waste and reduce CO2 emissions.

Individual components were made from recycled products, with each component being recyclable at the end of the project’s life.

A 47% reduction in construction person hours and minimal deliveries to site significantly reduced the project’s carbon footprint.

This decreased the amount of traffic movements, which not only reduced CO2 emissions, but noise and nuisance. This benefited the local villages and network.

To add to the legacy of the project, over 2000 trees were planted to the site perimeter to reduce the visual impact and provide new bird and bat habitats.

How was the project built?

Aligning with the Project 13 approach and agreeing outcomes across all parties at the start of the project meant the project delivered several benefits, including:

  • forging long term relationships throughout the supply chain,
  • delivering to mutually beneficial commercial arrangements,
  • establishing a common approach to health, safety and wellbeing, and
  • engaging suppliers early in the process to develop solutions.

A digital twin build model was developed to identify any build clashes and ensure that the build sequence considered health, safety, and the environment. This also prevented any unnecessary contractor congestion.

By digitally plotting each individual structure, the team was able to design the metalwork to fit at design stage and not during the construction phase.

People who made it happen

Client: Northumbrian Water Limited

Project Partners:

  • Tilbury Douglas Construction Limited
  • Wood PLC
  • Stortec
  • Aquardia
  • Intelect
  • MGL Group
  • JHT
  • Xylem