Remediation of a gasworks site for residential development: the Wharf Lane Site, Solihull, UK

I. Heasman and F.J. Westcott 

Abstract
This case study illustrates the successful regeneration of a complex contaminated gasworks site to a sensitive residential end use, including the use of an emerging and innovative remediation technology, namely chemical oxidation. It provides a technical summary of the ‘statutory’ and ‘development’ remediation processes, and the developer’s perspective on these.
The 10 ha Wharf Lane Site in Solihull, West Midlands, was formerly occupied by a coal gas manufacturing plant, together with ancillary activities such as gas storage, offices and a research station. The site was purchased by Taylor Woodrow Developments Ltd (TWDL) in early 2004, and is now one of the largest housing developments on a former gasworks currently under way in the UK.
’Statutory’ remediation is the process of removal or significant reduction of the risk of legal liability. This had been commenced by the previous site owners SecondSite Property Holdings (SPH) Ltd (now National Grid Property Holdings Ltd) and these activities were continued and concluded by TWDL. Benzene and PAH impacted groundwater was treated using in situ chemical oxidation in what is one of the largest scale programmes of its type seen in the UK. Statutory soil remediation comprised offsite removal of heavily PAH, hydrocarbon and metal impacted soils.
Further assessment and remedial actions beyond the scope of the ‘statutory’ remediation were required to bring the site up to a standard suitable for residential development. Closely managed delineation, remediation, hotspot removal and validation are being conducted to match the development phasing, and soil stabilisation was conducted to improve the geotechnical properties of backfilled materials. 

Key words: chemical oxidation, gas works, remediation, residential redevelopment 

Land Contamination & Reclamation, 14 (2), 2006, 189-193

DOI 10.2462/09670513.774 

Updated: 26-Jun-2006