HMP Featherstone

GEO-TECHNICAL AND GEO-ENVIRONMENTAL

SITE INVESTIGATION

Terra Firma (South) has extensive experience of the geotechnical and geo-environmental investigation of brown field sites to allow developers to comply with the requirements of Local Authority Planning Departments and the Environment Agency.

CASE STUDY: HMP FEATHERSTONE 2, SOUTH STAFFORDSHIRE

Terra Firma (South) acted as consulting geo-technical and geo-environmental engineers for the construction of the new HMP Featherstone 2. The project budget of £1.5 Billion is the most expensive outside London.

Between 1940 and 2002 the site was occupied by the Featherstone Royal Ordnance Factory (ROF).

The sites past land-use presented a particular challenge during the identification of specific contaminants of concern as individual buildings and areas were used for various processes during the manufacture of ammunition.

Subsequently, a Detailed Quantitative Risk Assessment (DQRA) was developed using the CLEA model and site specific assessment criteria. This involved an in-depth understanding of inmate ages, activities and sentences.

The DQRA progressed through Phase 3 Remedial Options and Phase 4 Validation in order to successfully satisfy the Local Authority Planning Conditions.

Efficient communication and project management by Terra Firma (South) facilitated a robust Phase II investigation, without compromising the logistical sensitivity and tight security of the site or the requirements of the site investigation.

The Phase II site investigation was undertaken using multiple intrusive investigation techniques; trial pits and windowless sampling boreholes to assess the geotechnical nature of the shallow made ground and superficial soils and deep rotary and cable percussive boreholes to determine the geotechnical properties and bearing capacity of the underlying faulted Wildmoor Sandstone Formation.

Terra Firma (South) provided an economical foundation solution using a combination of traditional, raft and piled foundations, which overcame variable design criteria. A particular challenge was devising a plan so that the alarm of the existing prison perimeter would not be triggered during piling.

Terra Firma (South) was able to manage the tight security restrictions, site area to time constraints and complex risk assessment parameters of this project to deliver.

For more information, click on: HMP Featherstone.