Greater Manchester Combined Authority brownfield sites

A potential brownfield site in Greater Manchester. Copyright Paul Grogan Photography 2019.

Brownfield sites (any site that has record of being previously developed) form a significant part of the Greater Manchester area. The Brownfield Ground Risk Calculator was originally developed for the Greater Manchester Combined Authority (GMCA) to help identify the scale of risks and abnormal (not anticipated) costs associated with ground conditions.

Such ground conditions may include:

  • soil and groundwater contamination
  • mining hazards (coal and other mining)
  • radon (natural radioactivity)
  • landfill
  • natural hazards, including:
    • landslides
    • shrink–swell clays
    • running sand
    • collapsible ground
    • compressible ground
    • soluble rocks
Manchester cityscape. Copyright Paul Grogan Photography 2019.

What does the calculator do?

The calculator estimates risk and risk mitigation costs derived from a range of environmental data available for the whole of the Greater Manchester area. The results are presented as digital maps that contain details of the environmental data source used to produce the risk scores and risk mitigation cost estimates. These maps are available to GMCA and the ten component local authorities.

Conceptual model for risks to from soil and groundwater contamination

The whole of Greater Manchester was divided into 50 m grid cells which were attributed with relavant environmental data, risk scores and cost estimates.


Four thousand seven hundred and seventy brownfield sites were analysed with the results are presented in a GIS in 50 × 50 m grid cells. Each cell is attributed with selected site information.

The ground risk score and mitigation cost estimate data are presented as two GIS layers: detailed site overview and generalised site summary. The scores reflect the risk that contamination might pose to human health and controlled waters and the potential effect of adverse ground conditions on the structural integrity of newly built homes.

Data sources

The calculator combines over twenty five environmental spatial dataset available for the whole of the Greater Manchester area to derive ground risk and mitigation cost estimates. Data sources include:

  • BGS
  • Coal Authority
  • Environment Agency
  • Ordnance Survey
  • Greater Manchester Combined Authority


Please contact Darren Beriro for further information.