Residential Development – Bristol
Bristol contains a surprising number of historical coal mine workings, primarily beneath the Kingswood area. The geology of the city is complex, and with competition from other coalfields mining entered into decline in the 20th century. The final colliery in Bristol closed in 1949.
A development consisting of eight residential dwellings was proposed in the Kingswood area of the city. As part of the planning submissions, Hydrogeo were commissioned to produce a Coal Mining Risk Assessment. The Coal Mining Risk Assessment showed that steeply dipping seams of coal were present at shallow depths beneath the site. The Coal Authority records indicated that these seams could have been mined, but no conclusive evidence was available.
Mine abandonment plans were obtained, showing the areas in the shallow coal seam which had been mined. Detailed review of the mine abandonment plans showed that mine workings had stopped before extending beneath the site. The Coal Mining Risk Assessment concluded that the risk to the site was from mine workings was low, and no further site investigation or remedial measures were required. The planning conditions associated with mining risk were discharged, and construction was able to start.
Energy Development – Chatterley Whitfield Colliery
Chatterley Whitfield Colliery is located in Staffordshire and was formerly one of the UK’s largest coal mines. It was the first mine in the UK to raise over 1,000,000 tonnes of coal in a year. The mine closed in 1977, and for a period was the site of a mining museum. The spoil heaps associated with the colliery have been landscaped and parts of the site have been earmarked for commercial development.
It was proposed that part of the site be developed to house standby generators to help meet peak electricity demands on the National Grid. Hydrogeo were commissioned to undertake a Coal Mining Risk Assessment for the site. The Coal Mining Risk Assessment found that the site was underlain by several thick coal seams at shallow depths, which were recorded as worked in conjunction with the deeper mined seams.
Hydrogeo progressed a program of site investigation consisting of rotary boreholes advanced to 35 metres below ground level in conjunction with trial pitting, soil sampling and a geotechnical assessment. It was determined that no coal seams were present at depths which could pose a threat to the generators. This allowed discharge of the planning conditions, and for the development to proceed.
Commercial Development – Leeds
Leeds lies partially within the Yorkshire Coalfield. The Yorkshire Coalfield contains mine workings covering some 3000km2 in over 20 coal seams. The mining of coal in Yorkshire dates back to Roman times, but only became widespread in the 17th and 18th centuries.
Planning permission was sought to convert a former cricket ground into a Dog Day Care Center with landscaping. It was proposed to convert the former cricket pavillion into the new site offices and reception. Property searches showed that the site was underlain by coal which could have been worked.
Hydrogeo undertook a Coal Mining Risk Assessment for the site. A detailed review of historical maps and geological memoirs provided a wealth of information on the coal seams beneath the site. The Coal Mining Risk Assessment proved that coal was present on the boundary of the site, but not underneath the site itself. Using borehole records the seam was proven to be thin, and was unlikely to have been mined. The overall risk to the development was shown to be Low, meaning that planning permission could be granted with no further conditions.
Commercial Development – Ilkeston, Derbyshire
The redevelopment of Bellini’s Service Station in Ilkeston, Derbyshire comprised the renovation of a petrol station and the construction of a new commercial store. Historically, numerous small coal mines were present in the local area, with many seams known to have been worked before statutory mine records were required.
Hydrogeo provided advice on the coal mining risk during the works. Geological mapping indicated that two coal seams were present under the site at shallow depths, and records indicated that the seams were widely mined in the local area.
Rotary probe drilling was commenced at four locations across the site whilst refurbishment of the petrol forecourt was underway. The probe holes confirmed the presence and depth of the two coal seams, which were found to be intact and unmined. Presentation of the evidence from the drilling proved that the site was stable, and The Coal Authority discharged the planning conditions.