On Site at “The Most Innovative Green Energy Scheme in the World”

UU’s £200m investment has enabled them to introduce new technology and processes, including the ability to convert sludge into high-grade fertiliser and biogas. The amount of biogas produced means that the treatment works is not only self-sufficient, but is able to supply gas back to the National Grid. Because of this, the Institute of Chemical Engineering has called Davyhulme “the most innovative green energy scheme in the world”.

The scheme is the largest live water project currently being constructed in the UK.

CHALLENGES

Serving a population of around 1.5 million and treating up to 314 Olympic swimming pools of water every day, Davyhulme is UU’s largest treatment works.

The facility – which remained live throughout Geotechnics’ work on site – is on the banks of the River Irwell in Urmston. The river was permanently altered by the construction of the Manchester Ship Canal in 1896. The straightening of the river involved the infilling of meanders with unknown and often contaminated materials. One of these former meanders travels under the treatment works.

Geotechnics was commissioned to investigate the impacts of this infilling and assess the risks from ground generated gas on any future development of the site. We carried out a series of investigations to determine the ground conditions and install a range of groundwater and gas monitoring instrumentation.

SAFETY, HEALTH, ENVIRONMENT & QUALITY

Careful planning and liaison with United Utilities’ Geotechnical and Geoenvironmental team was required to assess and control the risks of:

• working on a live facility
• the contaminated land environment
• working in areas with potential asbestos contamination
• impact on protected species including great crested newts
• no-go zones where Japanese Knotweed was identified on site

INNOVATION

• Developing a new sampling technique to safely allow recovery of asbestos contaminated soils
• Direct liaison with multi-disciplinary teams within United Utilities
• Direct links with a chemical contamination testing house

OUTCOMES

All parties worked together to successfully manage the technical and logistical challenges. Geotechnics provided technical and project management excellence, backed up by office based support to ensure that rig and staff utilisation was as efficient as possible. To date, over 40 gas and groundwater monitoring visits have been carried out by Geotechnics.

WHAT WE DID…

• Over 100 cable tool boreholes
  
• 16 rotary cored drill holes
• Over 100 windowless sampling boreholes
• Numerous trial pits/trench ex
• Instrumentation
• GasClam monitoring
• Surface, groundwater and gas sampling/monitoring
• Permeability testing
• Geotechnical and geochemical testing
• Factual reports
• AGS data management

Our North West office was proud to deliver site investigation services for United Utilities on this GE Awards nominated project. To find out how we can help with ground investigations across the UK, please contact our teams across the country.