Client: Feilden Clegg Bradley Architects
Location: Shrewsbury, Shropshire, UK
Services: Contaminated land site investigation and risk assessment
Summary: Contaminated land assessment supported the redevelopment of this site of significant industrial heritage
The Ditherington Flax Mill site in Shrewsbury is of major regional and national importance not least since the mill building was the world’s first commercial structure to be constructed around an iron frame. Nearly 200 years of industrial occupancy, prior to the closure of the Flax Mill (and subsequent Maltings) in 1987, offered significant potential for land contamination. The regeneration of the site was therefore a prime objective for both English Heritage and Shrewsbury and Atcham Borough Council (SABC).
The assessment of the site was conducted by combining a number of site visits with a desk study of available documentary evidence. Consultations were held with the Environment Agency, Natural England, Shrewsbury and Atcham Borough Council, Maltings Development Ltd. and various other third parties in order to provide a clear picture of the site’s history and environmental setting.
The desk study work enabled the development of an initial conceptual site model (CSM), including the identification of potential contaminant sources which included a former gas holder, rail sidings, dye house, coal store and several fuel and chemical stores. A qualitative risk assessment identified key pollutant linkages associated with both controlled waters, including the major Sherwood Sandstone aquifer and a local tributary of the River Severn, and intended future site occupants.
Informed by the initial CSM an intrusive site investigation was conducted across the site, combining trial pitting, hand digging and window sampling equipment. The laboratory sample results were critically examined in the context of the prevailing conceptual site model in order to clarify the likely source terms and allow meaningful site zoning. The subsequent risk assessment confirmed the presence of contaminant hotspots (these were typically linked with former land uses) and identified the need for additional targeted site investigation.