We worked for Southern Gas Networks (SGN) on the gasworks site in Croydon, which is the largest town in South London.

This project involved the decommissioning (desludging and dewatering) and demolition of two redundant gasholders along with the framework on a live Pressure Reducing Station gas site. The works included the dismantling of the gasholder and associated plant, along with other additional structures occupying the site and the infilling of all pits to leave an overall clear and level site.

The site-specific constraints were significant and included: working alongside a white tower operational facility, as well as around live services to remove Japanese knotweed in the area. The site access road had to be maintained for other contractors working on other parts of the site. This meant that no “lay-down” area was available to process the materials, which had to be stored on the dumpling within the gasholder and loaded via 14 metre-high ramps, both of which, along with the crane pads, consisted of over 6000 cube of 6f5 material.

Cranes and crushed materials were in short supply during these works as a direct result of the HS2 rail project which was ongoing at the time.

Site overview video:

We were appointed as the CDM Advisor for the project. Our roles included checking the Principal Contractor’s Construction Phase Plan (CPP) and reviewing the Risk Assessment and Method Statement (RAMS) for the project.

Throughout the project’s period, we carried out audits which were planned to coincide with the specific phases of the project. Such audits included the CDM compliance audit, a specific environmental audit to ensure the sludge and waste were removed in line with the Environmental Agency’s requirements, and a process-specific demolition audit.

• Review and comment on the Construction Phase Plan and issue a report.
• Review and comment on the Risk Assessments and Method Statement and issue a report.
• Carry out the pre-start CDM site audit and issue a report.
• Carry out the environmental site audit and issue a report.
• Carry out the demolition process site audit and issue a report.