Predicting Groundwater Rebound in the South Yorkshire Coalfield, UK

Abstract

The semi-distributed model GRAM (groundwater rebound in abandoned mineworkings) has been applied to part of the South Yorkshire Coalfield, UK, to predict the pattern of groundwater rebound, in particular the timing and rates of changes in mine water flows between abandoned collieries. The model is based upon the mining hydrogeologist's concept of 'ponds' (discrete volumes of interconnected workings) and calculates water balances over time for all ponds in a multi-pond mined system. GRAM was successfully calibrated against observed groundwater levels over a 5 year period from 2001 to 2005 before being used to predict future rates of groundwater rebound, in accordance with different scenarios, including average, low, and high rainfall scenarios. The results reveal that it could take up to 22 years before an inflow of water occurs into the last remaining colliery in the area at Maltby, with the first surface discharge expected in approximately 15 years time from an old mine shaft. If Maltby is closed and pumping ceases across the area, then it could be 100 years before groundwater rebound is complete.

Using the GRAM Model to Reconstruct the Important Factors in Historic Groundwater Rebound in Part of the Durham Coalfield, UK

“…Underground Water Survey" (NCB 1964). The latter provided water level data 'before rebound' with the assumption that the water level did not change significantly between 1964 and the beginning of the simulations (1968) (personal comm., Younger 2006 ). An additional significant source of data was a report by the local water authority "Report on survey of water resources" (Northumbrian River Authority 1973).…”

Discussion of “Oil and gas wells and their integrity: Implications for shale and unconventional resource exploitation” by R.J. Davies, S. Almond, R.S., Ward, R.B. Jackson, C. Adams, F. Worrall, L.G. Herringshaw, J.G. Gluyas and M.A. Whitehead. (Marine and Petroleum Geology 2014)

“…Again, the contrast with coal mines is telling -they generally ARE inter-connected all the way back to outcrop, and that is why we get significant water discharges from them (e.g. Kortas and Younger 2007;Gandy and Younger 2007); it is also noteworthy that once mine workings are drowned by rising groundwaters, any release of methane from them abruptly ceases (e.g. Hall et al 2005; Younger 2014) -there is no reason why depleted unconventional gas reservoirs should behave any differently when groundwater heads within them recover.…”

A simple, low-cost approach to predicting the hydrogeological consequences of coalfield closure as a basis for best practice in long-term management

“…Younger et al 1995;Sherwood and Younger 1997;Burke and Younger 2000;Adams and Younger 2001;Whitworth 2002;Boyaud and Therrien 2004;Winters and Capo 2004;McCoy et al 2006;Gandy and Younger 2007;Hamm et al 2008;Kortas and Younger 2007;Light and Donovan 2015). Post-audits of these applications have shown that they produce useful and realistic results, and that engineering design decisions based on their application have stood the test of time (Younger, 2004;Adams 2014).…”

“…Post-audits of these applications have shown that they produce useful and realistic results, and that engineering design decisions based on their application have stood the test of time (Younger, 2004;Adams 2014). For instance, the modelling study reported by Gandy and Younger (2007) was undertaken as part of a financial due diligence process during the sale of a profitable mine as a going concern, leading to extension of the life of the mine by eight years.…”

“…Typically, then, there is a 'Master Seam', the old workings of which provides the bulk of interconnectivity across the coalfield. For instance, typical Master Seams in some of the larger UK coalfields include: the Dysart Main Seam in the eastern Fife Coalfield (Younger et al 1995); the High Main Seam in the southeast Northumberland Coalfield (Younger 1998a); the Hutton Seam in the northern Durham Coalfield (Younger 1993a;1998a); the Barnsley Seam in the eastern Yorkshire Coalfields (Burke and Younger 2000;Gandy and Younger 2007); and the Top Hard Seam in Nottinghamshire (Edwards 1967, pp 96-99). It is common to find that other seams have been worked in relatively isolated patches, but these are almost always connected to the wider coalfield via shafts, roadways and cross-measures that communicate with the regional Master Seam.…”