Residential Development, Bristol Road, Iron Acton ,South Gloucestershire, BS37
Case Study Reference: CS22-01-02
Planning Authority: South Gloucestershire Council
Planning Reference: P21/07136/F and DOC22/00108
Synopsis:
As part of the application the contaminated land team were consulted on the application and the potential for the site to pose a risk to human health, as there is a historical industrial use for the site and the sensitivity of the development a contaminated land planning condition was attached to the decision notice.
The first stage of discharging the contaminated land planning condition (2) was to prepare a Phase I desk study report, this assesses the potential for a site to be impacted by using a wide range of sources including Ordnance Survey maps, information provided by regulators (Environment Agency, local authority, Coal Authority, BGS etc.).
The history of the site and the surrounds was researched using a combination of historical O.S. maps, aerial plates and street level imagery. The maps revealed the site was undeveloped until some time between 1955 and 1965 when the site formed part of Elm Farm, with the exception of the adjoining buildings associated with Elm Farm no other potentially contaminative land sues were identified. Street level imagery indicated the site had been used as a cattery and kennels from at least 2012.
A review of the planning history of the site did not reveal any salient information.
The large scale geological maps indicated that deposits of made ground were present within 250m of the site, the deposits were not identified on them small scale geological maps and the area of the made ground was identified as a railway cutting on the O.S. maps.
Deposits of alluvium were also not on the geological maps 20m south of the site.
Data provided by regulators identified ta discharge license had previously been registered at the site.
On completion of the desk based assessment a site walkover visit was undertaken, the confirmed the site was a former cattery/kennels and the site was occupied by four buildings, two of which were kennels.
An area formerly occupied by a fuel tank was 
identified as part of the walkover survey.
On completion of the site visit a qualitative risk assessment was undertaken in order to determine which of the potential sources warranted further investigation, this concluded that the potential for made ground to be present on site, former fuel tank, damaged cement sheeting and alluvium warranted further investigation.
The desk study report was submitted to partly discharge the contaminated land planning condition (DOC22/00108), the proposals were accepted and the clients preferred option of the incorporation of gas protection measures in lieu of monitoring was accepted.
The Phase II works were undertaken in July 2022, as the site was still active at the time of the investigation the method of investigation was changed to dynamic sampling in order to reduce the disturbance caused to the hard-standing and was undertaken over three days.
The boreholes recorded a thin layer of made ground (sub base) under the concrete hard-standing, which in turn was underlain by clay. Sandstone bedrock was also identified at approximately 1.8mbgl.
Samples of made ground were subject to chemical analysis as well as surface samples and additional samples from the area of the former fuel tanks.
The quantitative risk assessment indicated that the made ground on the site was impacted by metals and PAH’s, the data from the area of the tanks revealed np evidence of hydrocarbon releases and the surface samples were not imp[acted by asbestos.