Difference between revisions of "OR/19/052 Appendix 3a - Array 1 Borehole descriptions"
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Latest revision as of 15:23, 17 December 2019
|Kingdon, A, Fellgett, M W, and Spence, M J. 2019. UKGEOS Cheshire Energy Research Field Site - Science infrastructure. British Geological Survey Internal Report, OR/19/052.|
Contributors: Midgley, J, Elsome, J W, Dearden, R A, Chapman, C, Burke, S P, Hough, E, Luckett, R R, and Bianchi, M.
|Array 1: Sampling||Details|
|Scientific Objective:||Long-term baseline groundwater testing and sensor installation|
|No of Sites and boreholes per site||9 Sites each with both 1 x 100 m and 1 x 50 m borehole|
|Expected Lithostratigraphy at TD||50 m boreholes TD in Quaternary, 100 m TD in Sherwood Sandstone Group (Triassic)|
|Boreholes per site||1 x 100 m, 1 x 50 m boreholes|
|Likely borehole diameter||13½ nominal diameter|
|Casing Installed: 50 m boreholes||10¾" permanent steel casing (6–22 mbGL), 150 mm PVC screened between 43 to 49 mbGL|
|Casing Installed: 100 m boreholes||11¾" permeant steel casing (6–22 mbGL), 150 mm PVC screened between 90 to 99 mbGL|
|Expected end use||Boreholes remain open for future sampling|
|Samples available during drilling||Drill cutting collected sporadically|
|Cored Boreholes||5 X 100 m cored to sample superficial & Permo-Trias geology|
|Geophysical logs||5 x 100 m boreholes, Gamma-Ray — Caliper (Borehole diameter)|
|Geomicrobiology sampling||Standard geomicrobiology sampling protocol: 1 sample per 10 m of core in cored boreholes|
|Gas testing during drilling||Equipment|
|Fluid testing during drilling||None planned|
|Fluid Testing Post Drilling||None planned|
|Pump Testing||Long-term Pump testing|
|Permanently installed equipment||Automated & telemetered data logging in 6 boreholes|
The array will provide environmental baseline data of the groundwater, ground motion and air quality across the study area. The purpose of the proposed groundwater array is to create a new groundwater monitoring network which will allow researchers to get an improved understanding of the groundwater processes within the Cheshire Energy Field Research Site (CERFS) area. These data will form the natural baseline against which future research activity will be compared.
Borehole components of array 1
The array consists of 18 boreholes at 9 separate locations in the broad vicinity of the village of Elton in Cheshire. This allows the sampling of the regional groundwater in the vicinity of the CERFS research site and also allows the stratigraphy and variability of the Permo-Triassic geology to be more completely understood.
Following completion of the drilling phase a series of pump tests will be undertaken at each borehole location. In addition these boreholes will also be instrumented with continuously recording sensor to allow the borehole steady-state conditions to be monitored remotely over an extended time interval. Combined with outputs from analytical groundwater geochemistry this will produce a laterally and temporally extensive baseline data set.
Above-ground data acquisition in array 1
Interferometric synthetic-aperture radar (InSAR) ground motion equipment will also be installed across selected sites at the CERFS area. Equipment will be installed at the surface to continuously monitor deformation or shifts in rock mass in the subsurface. Air quality monitoring installations are included as part of the environmental baseline study for the CERFS area. These are designed by (and will be controlled by) Manchester/York Universities and NCAS1. These installations will include a range of sensors and instruments to monitor atmospheric gases.
Subsurface data acquisition in array 1
The groundwater monitoring wells within this array allow an environmental baseline for groundwater quality to be produced. The baseline will detail various chemical and physical parameters and general groundwater quality through the collection of groundwater samples and continuous automated monitoring, using data loggers and groundwater quality sondes, over an extended period. The sondes will be purchased, installed and maintained by the UK Geoenergy Observatories capital funding.
The array is also designed to allow pumping tests to be undertaken during the operational phase of the wells. This will help to characterise how the groundwater flows and behaves across the region.
|Location||100 m BH||Cored||50 m BH|
|Sample Type||Treatment||Sample Container||Analysis Possible|
|FA 30 ml||Filtered acidified with HNO3 to 1%||30 ml LDPE||ICP AES, Na, K, Ca, Mg, SO4, Si, Al, B, Ba, Be, Cd, Co, Cr, Cu, Fetotal, La, Li, Mn, Ni, Mo, Pb, Ptotal, Sc, Sr, V, Y, Zn, Zr, As, Se, ICP MS suite|
|FUA 60 ml||Filtered, unacidified||60ml LDPE||Cl, F, Br, I, NO2, NO3, TON, NH4 (SO4, PO4)|
|FUA 30 ml NH4||30 ml LDPE||Ammonium|
|FUA 30 ml As||Arsenic|
|NPOC||Silver filtered, unacidified||14 ml foil capped glass vial||Dissolved Organic Carbon|
|δ18O/δ2H||Filtered, unacidified||60 ml HDPE||Oxygen and Deuterium|
|δ13C||100 ml HDPE||Carbon Isotopes|
|Dissolved gases||Unfiltered, unacidified||Gas Sampling Bomb||Dissolved gases|
|CFCs||Small Amber Bottle||CFCs|
|SF6||Clear Glass Bottle||SF6|
|SVOCs||1 x Green Bottle
2 x Glass Vials
|NORM||1L Glass Amber Bottle||NORMS|
|Tritium||1L Glass Amber Bottle||Tritium (3He)|
|S Isotopes||250 ml Nalgene||Sulphur Isotopes|
|Radon Daughters||Nalgene pots||Radon Daughters|
|Radon||60 ml HDPE||Radon (Rn)(Triathler)|
|Organic micropollutants||2 x 1 L PTFE Lined Bottles||GCMS/LCMS|
|PAHs||1 x 1 L PTFE Lined Bottles||PAHs|
|VOCs||1 x 250 ml plastic bottle||Chlorinated hydrocarbons, BTEX|
|Type||Data Collection||Data Produced/Possible||Status|
|Pumping Tests||Step Drawdown||Well efficiency, critical pumping rate, optimum pumping rate||Operational details to be confirmed|
|Constant Rate||Transmissivity (hence hydraulic conductivity), storage coefficient, aquifer response|
|Constant Head||Transmissivity (hence hydraulic conductivity)|
|InSAR||Ground level monitoring||Baseline of ground level stability||Confirmed|
Special sample handling procedures that will be adopted:
- One sample will be acidified in the field
- The majority of samples will be filtered
- Samples will be refrigerated in the field using ice packs/ice and kept in cold stores over the weekend before shipping to labs
- There is scope to keep some samples in the cold store for testing at a later date
- Further parameters need to be further examined including long-term storage requirements