Construction of an Apartment Block, St Johns Road, Newbold, Derbyshire

Case Study Reference: CS18-06-01

Planning Authority: Chesterfield Borough Council

Planning Reference: https://www.chesterfield.gov.uk/planningapplications and https://publicaccess.chesterfield.gov.uk/online-applications/applicationDetails.do?activeTab=documents&keyVal=QZQBBQEP00L00

Synopsis:

In order to demonstrate that after the development the site could not be classified as ‘contaminated land’ under Part 2A of the Environmental Protection Act a Phase I desk study report was required to support the application for residential redevelopment of the site.

Also due to the site being within a ‘Development High Risk Area’ the Coal Authority raised an object to the application until the applicant had submitted a Coal Mining Risk Assessment (CMRA) demonstrating the risks from surface instability from worked coal seams had been taken into account.

Demeter Environmental were commissioned to prepare both reports to support the planning application.

The aim of a CMRA is to identify any coal mining legacy risks and set out a proposed mitigation strategy to demonstrate to the LPA (Local Planning Authority) that the site can be made safe and stable for the proposed development. In some cases it may be possible to ensure that the development layout avoids recorded high risk features.

The published geology indicated that no drift soils were recorded to be present and the bedrock would be exposed or close to the surface.  The solid geology was given as the Pennine Lower Coal Measures Formation of the Westphalian Epoch.

The borehole section sheets published by the BGS were reviewed and no boreholes in close proximity to the site were available.

Data provided by the Coal Authority confirmed the site was in a ‘Development High Risk Area’ due to the presence of probable unrecorded coal seams close to or at the surface (within 30m of the surface).

Based on the assessment of the potential risks the CMRA concluded that there was a risk to the development from the worked seams and proposed either further investigation. It was proposed that initially a single rotary borehole to 30mbgl would be sunk with a further two if there was evidence of coal seams.

Parallel to the CMRA the Phase I desk study report was prepared. The 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 (1876) open land, no evidence of development could be discerned and the 2017 aerial plate indicated the site was overgrown and a number of cars were resent on the site.

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, no previous applications were noted.

The published geological maps indicated no drift soils were recorded to be present. The solid geology given as the Pennine Lower Coal Measures Formation (mudstone, siltstone and sandstone) and the Woodhead Hill Rock (sandstone) of the Langsettian Sub-age.

Made ground (void) was identified on the 1:10,000 scale geological maps 245m west fo the site.

A review of the BGS borehole database indicated no boreholes were available in close proximity to the site.

Data provided by regulatory bodies identified a brickyard 189m north of the site as well as a scrap yard 46m north east of the site.

The sensitivity of controlled waters was undertaken to determine if the site posed a risk to the nearby controlled waters, this concluded that as the controlled waters were of low risk due to the site not being within a Source Protection Zone (SPZ), no further assessment was warranted.

On completion of the desk based research a site reconnaissance visit was undertaken, this confirmed the site comprised of an overgrown parcel of land with demolition rubble present on the southern area.

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 potential for made ground to be present on the site and the potential for worked coal seams under the site all warranted further investigation.

The report concluded that further works were required to assess the potential for the site soils to pose a risk with the risk from worked coal seams further assessed on completion of the coal mining rotary boreholes.

Both reports were submitted to support the application, the recommendations of the CMRA were accepted.

As of May 2023 the development had not commenced.