Erection of a Dwelling, North Road, Yate, South Gloucestershire, BS37

Case Study Reference: CS19-10-05

Planning Authority: South Gloucestershire Council

Planning Reference: PK18/2376/O and P20/04127/RM |

Synopsis:

Given the proximity of the site to Yate Colliery 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 undeveloped until a building was noted on the 1999 aerial plate. Yate Colliery (number 2) formed the eastern boundary.

The planning history of the site was reviewed as part of the desk based research, no previous applications were noted.

Large scale geological maps identified deposits of made ground on the eastern boundary of the site (in the area of the colliery), both scale maps indicated that drift soils were not recorded to be present and the bedrock (South Wales Middle Coal Measures Formation) would be exposed at the surface.

Borehole published by the BGS were reviewed, which revealed a borehole was available within 50m, which related to a mine entry and provided by details of the geology.

Data provided by regulators indicated that a number of workings associated with the colliery were present to the east of the site including a tramway as well as a coal pit to the north of the site.

The sensitivity oF controlled waters was undertaken and givcen the absence of any abstractions and Source Protection Zones the sensitivity of the bedrock was regarded as low.

On completion of the desk based research a site reconnaissance visit was undertaken, this confirmed the site was occupied by a stable block, paddocks and access track.

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 made ground that had been brought onto site had the potential to be impacted by elevated concentrations of contamination.

In order to assess the potential risks the options of intrusive investigation and remediation in lieu of investigation were proposed.

The Phase I report was submitted with P20/04127/RM, the recommendations of the report were accepted and the condition partly discharged.

The site investigation was undertaken in October 2020, which comprised of the excavations of a number of trial pits across the site, this revealed that made ground was present in isolated locations on the site. Chemical testing confirmed the made ground was impacted by PAH’s and heavy metals.