Erection of 10 Dwellings, Stump Lane, Chorley, PR6

Case Study Reference: CS17-10-14

Planning Authority: Chorley Council

Planning Reference: 17/00616/FULMAJ and 18/00263/DIS

Synopsis:

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 developed prior to the first edition (1849) map and was occupied by Highland House. The 1959 map identifies the building on site as a works.

Street level imagery confirms the building on the northern boundary was used by Mind.

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, five applications were noted with the design and access statement from 17/00616/FULMAJ confirming the building was in use until June 2015.

The published geological maps identified deposits of made ground 50m from the site (large scale maps only) with e drift deposits being given as Devensian Glacial Deposits. The bedrock was given as the Pennine Lower Coal Measures Formation (mudstone, siltstone and sandstone) of the Langsettian Sub-age.

Data provided by the Coal Authority indicated that the site is not within a “Development High Risk Area”.

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 a number of ponds within 250m of the site.

The sensitivity of controlled waters was undertaken to determine if further assessment of the risks to controlled waters were warranted, given the bedrock as a Secondary aquifer, the site not being within a Source Protection Zone (SPZ) and the presence of low permeability drift the sensitivity of the controlled waters was regarded as low and no further assessment was warranted.

On completion of the desk based research a site reconnaissance visit was undertaken, this confirmed the demolition had commenced with stockpiles of demolition rubble present on the site.

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 past uses of the site had the potential to impact site soils and further assessment was warranted.

The Phase I report as well as a Phase II report prepsared by others was submitted (18/00263/DIS) to partly discharge the contaminated land planning condition, the ‘Decision – Discharge Of Condition’ confirms the recommendations of the report were accepted and the condition partly discharged.