Given the sensitive nature of the development (residential) a contaminated land planning condition was attached to the decision notice for the proposed development.

The first stage of discharging the condition was to prepare a Phase I desk study report in order to determine if the site has the potential to be impacted by elevated levels of contamination, and to determine the source as well as the likelihood of the risk occurring.

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.

The history of the site and surrounds were researched using a combination of Ordnance Survey (O.S.) maps, street level imagery and aerial plates, this revealed the site was initially 1851) the site comprised of open land, the site was developed between 1968 and 1970 when the site was occupied by a detached dwelling. A reservoir was noted to the south of the site which was identified as marshland from 1937.

Street level imagery of the site confirmed the site was occupied by a dwelling.

 

The planning history of the site was reviewed as part of the desk based research and reports associated with any previous application were located and studied and no previous applications were noted.

The published geological maps identified the site drift as Devensian Till with Devensian Glaciofluvial Deposits (sands and gravels) on the north western corner of the site. The bedrock was given the Pennine Lower Coal Measures Formation (mudstone, siltstone and sandstone) of the Langsettian epoch.

A review of the BGS borehole database did not reveal any boreholes in close proximity to the site.

Data provided by regulatory bodies confirmed the presence of reservoirs, a quarry and a pit within 250m of the site.

The sensitivity of controlled waters was undertaken to determine if the site posed a risk to the nearby water bodies, this concluded that as the bedrock was of low risk indicating the groundwater was not a credible receptor.

On completion of the desk based research a site reconnaissance visit was undertaken, this confirmed the site comprised of a two story dwelling, residential garage and gardens.

Once the walkover survey was completed a qualitative risk assessment was undertaken on the potential sources of contamination identified in the desk study report in order to determine if any warranted further investigation, this concluded that the risk of the site being affected by ground gases from off site sources warranted further assessment.

Based on the potential sources of ground gases it was proposed that gas protection measures in lieu of monitoring was appropriate for the development.

The Phase I report was submitted (17/00510/DOC) to partly discharge the contaminated land planning condition, the decision notice confirming the recommendations of the report had been accepted.