Central and southern Scotland

Regional summary

In central and southern Scotland, 31 sites have been sampled for methane from a number of different sedimentary aquifers, mostly from the Carboniferous Clackmannan and Coal Measures groups in central Scotland. Here, groundwater was historically an important resource for industry, but today is not widely used. In southern Scotland there is local groundwater abstraction for agriculture and domestic use.

Geology of central and southern Scotland

The Clackmannan Group and Coal Measures Group form multi-layered and vertically segmented aquifers, in which fine-grained, well-cemented sandstone layers act as discrete aquifer units in which groundwater flow is predominantly through fractures, and which are separated by lower permeability siltstones, mudstones or coals. Groundwater may be present at various depths under unconfined or confined conditions, and different groundwater heads are seen in different aquifer layers. The thickness of the Carboniferous sedimentary aquifers varies from less than 500 m in southern Scotland to 3000 m in central Scotland.

In this area the formation which is most likely to have potential for shale gas and/or oil is the West Lothian Oil-Shale Formation, which lies stratigraphically immediately below the Clackmannan Group in the eastern part of central Scotland.

Methane in UK groundwater results

These summary results are from single sampling visits to each site as part of the Baseline Scotland project. The data are summarised for the central and southern Scotland regions as a whole, and also for individual aquifers, where enough data are available.

Methane samples and concentrations in central and southern Scotland
Methane concentrations chart for central and southern Scotland
Area Concentration (mg/l) Number of
samples
Minimum Median Maximum
Central and southern Scotland <0.0001 0.0036 1.68 31
Clackmannan and Coal Measures Groups <0.0005 0.00835 1.68 18


Baseline groundwater quality data

A summary of the baseline quality of groundwater in this area is below. This data was collected as part of a collaborative project between BGS and the Scottish Environment Protection Agency to investigate the baseline quality of groundwater in major Scottish aquifers.

Groundwater from the Clackmannan and Coal Measures Groups in this area is typically reducing and contains a high proportion of old water, recharged more than 35–60 years ago. Mining activity in this area has had a major impact on groundwater quality. More detail on groundwater quality for central Scotland and southern Scotland is available via the Baseline Scotland web pages.

Analysis Concentration (mg/l) Number of
samples
Minimum Median Maximum
Ca 7.26 54.5 290 21
Mg 3.11 17.5 96.2 21
Na 6.2 15.5 461 21
K 0.64 3.08 26.8 21
Cl 5.14 20.7 1230 21
SO4 3.82 48.5 244 21
HCO3 7 265 734 21

Contact

Contact Rachel Bell for further information.