UK's Davyhulme Upgrade to Process Sludge for Power

Davyhulme in Manchester, one of the United Kingdom’s largest wastewater treatment works, is set to become a valuable source of renewable energy.

Black & Veatch will design and construct the upgrade of the facility as principal contractor under United Utilities’ Sludge Balanced Asset Programme. Improvements will double sludge treatment capacity. The project will produce biogas sufficient to generate electricity for running the new treatment process and for feeding the National Grid.

The £75 million-sludge treatment contract includes

  • sludge reception, thickening and blending facilities;
  • Cambi thermal hydrolysis process; and
  • sludge digestion and sludge dewatering facilities.

The thermal hydrolysis plant will increase capacity of existing digesters by nearly 130 percent and allow United Utilities to import and treat sludge from other treatment plants in northwest England.

The highly treated biosolids could be applied to land as fertilizer or a feedstock to the Mersey Valley Sludge Processing Centre and the biogas will be used in a combined heat and power plant to generate up to 10 megawatts of electricity.

The plant, which has been in operation since 1894, is expected to handle around 91,000 tons of dry solids per year. It serves a population equivalent of 1.2 million in and around Manchester.

Pete Robinson, United Utilities program manager, said, "Sludge treatment is a 24-hour process, so there is a continuous supply of biogas. It is a very valuable resource and it is completely renewable. By harnessing this energy, we can reduce our fuel bills and reduce our carbon footprint."

According to Steve Canney, Black & Veatch senior vice president, "We have leading experience in optimizing the environmental benefits of advanced sludge treatment plants, such as using the Cambi process selected for Davyhulme. This is an opportunity for us to help United Utilities achieve its carbon dioxide reduction targets by extracting more of the energy available in sewage sludge."

The contract is planned to begin in early 2010 with initial operation in autumn 2011 and completion in late 2012.