Environmental baseline monitoring

A range of environmental baseline monitoring activities is planned for the research site area, both adjacent to and in the area surrounding the boreholes. These include:

  • ground motion
  • soil/ground gas
  • soil chemistry
  • surface water
  • groundwater monitoring
  • seismic monitoring

Examples of the equipment which will be used for baseline monitoring

The planned research compound at GGERFS01
A typical research compound - GGERFS02

Ground motion

Ground motion monitoring in the Glasgow area is designed to detect the occurrence of any instability (subsidence, uplift or stability) of the target area before, during, and following subsurface research activities using Synthetic Aperture Radar (SAR) images, which have been acquired since 1995. The interferometric processing of the available SAR imagery (InSAR) has been designed to provide displacement measurements at different times with millimetre accuracy.

Assessment of the InSAR data is ongoing over a much wider area of Glasgow than immediate boreholes sites. To improve the calibration and accuracy of future InSAR data a passive InSAR reflector will be installed at Site 05 and an active reflector will be installed at Site 01.

The data generated from this infrastructure includes:

  • InSAR results of the average ground motion and relative time-series
  • Geological interpretation of the InSAR data in order to identify the extent and origin of any possible ground movement.

Soil/ground gas

Passive trihedral corner reflector for SAR imagery

Soil or ground gas* monitoring is essential to provide baseline data on mine gas risk at key points (e.g. near shafts, faults, where coals come to outcrop, boreholes) to detect existing mine gas reaching the surface. It will also provide information on gases occurring from artificial ground deposits and from natural soils. The soil gas baseline study will involve a phased programme of work for monitoring/measurement of soil gas concentrations and flux and near-ground atmospheric gas concentrations to establish the environmental baseline before any research activities begin.

(*ground gas at a depth of c. 80-100 cm, in general providing ground gas concentrations free from atmospheric dilution effects and remaining in the vadose zone)

Soil gas walkover surveys were undertaken in areas including and surrounding the planned borehole compounds GGERFS01-05 in August 2018 prior to any construction activities on site. Ground gas samples were collected and flux measurements were taken.

Continuously recording soil gas probes are planned for Sites 01, 02, 03, and 05. Two scanning lasers are planned for Site 01 for the purpose of continuous monitoring of near surface CO2 and CH4 in air.


Typical reflector
Scanning laser

Data from the soil gas monitoring probes will be downloaded monthly and made openly available. A continuous, live data feed is planned to be available from the scanning lasers.

Soil chemistry

A soil geochemistry monitoring programme will characterise baseline conditions and support the future science-based activities. Previous BGS soil surveys and site investigation reports for inorganic substances and persistent organic pollutants (POPs) have indicated that there is some, highly variable land contamination in soils in the area.

Two sampling rounds are planned:

  1. prior to drilling – completed in March 2018
  2. after the ground disturbance of putting boreholes in place to establish the pre-operational soil chemistry environmental baseline

Unlike fluid chemistry, soil chemistry does not change significantly over seasonal temporal scales so future sampling is recommended after the facility has been operating for 2-3 years. The soil quality monitoring programme aims to:

  1. improve the scientific understanding of the near-surface environment and interactions with the subsurface in the study area
  2. support interpretation of water quality data
  3. provide information on ground conditions; help meet regulatory requirements and provide public reassurance

In March 2018, ten samples were collected from 0-20 cm depth from each planned borehole site and from two control sites using locations determined for statistical validity. Laboratory analyses of major and trace elements, pH, total organic carbon (TOC), total inorganic carbon (TIC) and Cr6+ speciation, total petroleum hydrocarbons (TPH) and polycyclic aromatic hydrocarbons (PAH) as well as polychlorinated biphenyles (PCBs) that are of environmental concern will are ongoing.

Surface water

Surface water data BGS, ©UKRI, contains Ordnance Survey data ©Crown Copyright and database rights 2018.

An environmental surface water quality monitoring task programme will characterise baseline conditions and help direct future science-based activities. Surface water quality monitoring will be carried out with the baseline groundwater monitoring and will take place over a minimum 12-month period starting in autumn 2018.

The aims of the surface water monitoring programme are to:

  • improve the scientific understanding of the surface water environment and groundwater-surface water interactions to aid hydrogeological model characterisation
  • establish a surface water sampling network to generate benchmark information for a 12-month baseline period, including spatial and temporal variability, against which any future research results can be compared to identify any environmental change(s) resulting from the proposed activities.
  • this could be extended to a future longer-term programme suitable for detecting environmental change resulting directly or indirectly from research activities and, potentially, other anthropogenic influences;
  • contribute to the assessment and management of risks associated with geothermal resource development and help to meet regulatory requirements

Sample locations are limited by the small number of exposed watercourses (many are culverted) and access to them.

Analyses of pH, alkalinity, redox potential, specific electrical conductance, temperature, dissolved oxygen, non-purgeable organic carbon, total inorganic carbon, hydrogen, oxygen and carbon isotopes, major and trace elements, Cr6+ speciation, total petroleum hydrocarbons (TPH) and polycyclic aromatic hydrocarbons (PAH) will be carried out.

Groundwater monitoring

The boreholes at GGERFS 01-05 will have repeated monthly groundwater sampling and continuous hydraulic head, groundwater temperature and specific electrical conductivity monitoring . See the borehole arrays description for further information.

Seismic monitoring

The seismic monitoring borehole at GGERFS10 will provide continuous data from a string of broadband seismometers, see the borehole arrays description for further details.

Further information

Summaries of surface water, soil chemistry, baseline seismicity and engineering geology datasets

Monaghan, A A, Ó Dochartaigh, B, Fordyce, F, Loveless, S, Entwisle, D, Quinn, M, Smith, K, Ellen, R, Arkley, S, Kearsey, T, Campbell, S D G, Fellgett, M, Mosca, I. 2017. UKGEOS — Glasgow Geothermal Energy Research Field Site (GGERFS): initial summary of the geological platform. British Geological Survey Open Report OR/17/006.

Ground motion

Bateson, L, Novellino, A, and Jordan, C. Currently in review. Glasgow Geothermal Energy Research Field Site — ground motion survey report. British Geological Survey Open Report OR/18/054.

Soil chemistry

Fordyce, F M, Nice, S E, Lister, T R, Ó Dochartaigh, B É, Cooper, R, Allen, M, Ingham, M, Gowing, C, Vickers, B P, and Scheib, A. 2012. Urban soil geochemistry of Glasgow. British Geological Survey Open Report OR/08/002.

Kim, A W, Vane, C H, Moss-Hayes, V L, Beriro, D J, Nathanail, C P, Fordyce, F M, and Everett, P A. In press. Polycyclic aromatic hydrocarbons (PAH) and polychlorinated biphenyls (PCB) in urban soils of Glasgow, UK. Earth and Environmental Science: Transactions of the Royal Society of Edinburgh.

Surface water

Fordyce, F M, Ó Dochartaigh, B É, Lister, T R, Cooper, R, Kim, A, Harrison, I, Vane, C, and Brown, S E. 2004. Clyde tributaries: report of urban stream sediment and surface water geochemistry for Glasgow. British Geological Survey Commissioned Report CR/04/037.

Smedley, P L, Bearcock, J M, Fordyce, F M, Everett, P A, Chenery, S, and Ellen, R. 2017. Stream-water geochemical atlas of the Clyde Basin. British Geological Survey Open Report OR/16/015.

Stress and seismicity of central Scotland

Baptie, B, Segou, M, Ellen, R, and Monaghan, A. 2016. Unconventional oil and gas development: understanding and monitoring induced seismic activity. British Geological Survey Open Report OR/16/042.

Geological models

Kearsey, T I, Whitbread, K, Arkley, S L B, Finlayson, A, Monaghan, A A, Mclean, W S, Terrington, R L, Callaghan, E, Millward, D, and Campbell, S D G. In press. Creation and delivery of a complex 3D geological survey for the Glasgow area and its application to urban geology. Earth and Environmental Science: Transactions of the Royal Society of Edinburgh.

Contact

For more information, please use the UK Geoenergy Observatories contact form.