The site, part of the M60 widening scheme, included a licensed landfill with a residential area nearby.

We reviewed the existing gas, soil and groundwater data and our risk assessment indicated an unacceptable level of gas risk posed to the houses. The gas concentrations recorded on the site also exceeded the Landfill Licence surrender conditions.

Further ground investigation and gas monitoring led to the design of a unique gas venting system that reverses the gas pressure gradient and direction of gas migration. This removes the potential risk to the existing houses and, at the same time, will allow the former tip to be restored for public open space.