Conversion of Former Smithy to a Dwelling, St Mary Magdalen, King's Lynn, Norfolk

Based on the information provided with the application and the sensitivity of the proposed development (residential) a contaminated land planning condition was attached to the decision notice.

In order to discharge the contaminated land planning condition attached to the decision notice for the proposed development Demeter Environmental were commissioned to prepare the reports to discharge the condition.

The first stage was to prepare a desk study report, a  desk study determines what issues relating to historical contamination may affect the site, this is undertaken by reviewing the site history using a combination of O.S. maps, aerial, plates and street level imagery, a review of data held by regulatory bodies (Environment Agency, local authority, BGS etc.) as well as a site walkover survey.

A review of historical O.S. maps the site had been previously used as a smithy with a ramp to the rear of the site. A pond and a burial ground were also identified on the O.S. maps.

Data provided by regulatory bodies indicated that the site had bene used by an agricultural contractors (SD Warren).

On completion of the desk based assessment a site walkover survey was undertaken, this revealed the site was a former barn with lean to structures, at the time of the survey the site was used as an ironmongers.  Storage tanks were noted on the eastern and northern areas.

The assessment of the potential sources of contamination discounted the majority of potential sources, the remaining potential sources were the made ground on site, and the past uses of the site.

Due to the potential issues on the site a Phase II intrusive investigation was proposed, the Phase I report was submitted and approved by the local authority (accessible via the documents associated with 11/00275/F).

The Phase II investigation was undertaken in April 2014 and comprised of the excavation of a number of trial pits across the site, the subsequent chemical analysis and quantitative risk assessment identified that the made ground on the site posed a risk to human health, water mains and concrete.

In order for the development to proceed the methodology of how the remediation would be undertaken and validated (Phase IIIa Implementation Plan), which was prepared and approved by the local authority prior to commencement.

The validation of the remediation was undertaken during the construction phase of the development, the Completion Report was submitted with 14/00690/F  as a new application was submitted for the site. Both the completion report and confirmation of the acceptance of the report is given with 14/00690/F.