Long-term water quality trends at a sealed, partially flooded underground mine

Stoertz, Mary W.; Hughes, Michael L.; Wanner, Nathaniel S.; Farley, Mitchell E.

doi:10.2113/gseegeosci.7.1.51

Cited by 15 publications

(9 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Previous studies (López and Stoertz 2001;Stoertz et al 2001) of the abandoned mines in the region have shown seasonal variations with respect to discharge, with the highest discharge usually occurring in the spring months and the lowest occurring during summer when evapotranspiration is highest. The Corning discharge has variable flow, from \28 L s -1 to [140 L s -1 (\1 to [5 cfs), and high acidity and iron loads, averaging 593 kg day -1 acidity and 257 kg day -1 iron (McCament 2004).…”

Section: Site Descriptionmentioning

confidence: 95%

Using Time Series Analysis of Coal Mine Hydrographs to Estimate Mine Storage, Retention Time, and Mine-pool Interconnection

2009

Self Cite

View full text Add to dashboard Cite

Understanding flow-system dynamics of underground coal mine complexes is essential to designing in-situ remediation. Such complexes can be studied by applying time series analysis to the precipitation series and well and mine discharge hydrographs. The Corning mine complex discharges acid mine drainage into Sunday Creek in Ohio, USA. Analysis of the Corning discharge shows that the aquifer has a short (9 days) response time and has little capacity for long-term storage. A time lag of 3-4 days occurs between precipitation and discharge, which corresponds to pressure pulse propagation displacing stored mine water, rather than actual advective flow of water. A gradual decline in hydraulic head is observed from the unsaturated recharge area to the fully flooded discharge area. All well hydrographs show a similar seasonal trend, with mine water levels peaking in early summer, and reaching their lowest levels in early fall, consistent with seasonal recharge patterns. A relatively isolated and fully saturated portion of the mine is sensitive to diurnal barometric pressure, as is typical of confined aquifers, with well water level declining as pressure increases. Other portions of the mine behave as unconfined aquifers, insensitive to barometric pressures. The results also demonstrate the important spatial heterogeneity of the aquifer and indicate that the mine does not behave as a single pool.

show abstract

Section: Site Descriptionmentioning

confidence: 95%

Using Time Series Analysis of Coal Mine Hydrographs to Estimate Mine Storage, Retention Time, and Mine-pool Interconnection

2009

Self Cite

View full text Add to dashboard Cite

show abstract

“…However, considerable transience is typically observed in the quality of these outflows, with the concentrations of pollutants being highest in the period immediately following initial onset of outflow, with a gradual improvement over time until an asymptotic level of pollution is established (Younger 1997;Wood et al 1999;Gzyl and Banks 2007). Unfortunately, this asymptotic level all too often still exceeds the assimilatory capacity of the receiving water body, so that long-term treatment of the polluted water is required (Younger 1997;Stoertz et al 2001). Predicting the locations, flow rates and quality of mine water outflows is therefore highly desirable if uncontrolled pollution is to be avoided.…”

Section: Why Predict Post-closure Hydrogeology Of Coalfields?mentioning

confidence: 99%

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

Younger

2016

International Journal of Coal Geology

View full text Add to dashboard Cite

A simple, low-cost approach to predicting the hydrogeological consequences of coalfield closure as a basis for best practice in long-term management. International Journal of Coal Geology, 164, pp. 25-34. (doi:10.1016/j.coal.2016 This is the author's final accepted version.There may be differences between this version and the published version. You are advised to consult the publisher's version if you wish to cite from it.http://eprints.gla.ac.uk/120112/ The closure of individual coal mines usually entails a cessation of mine dewatering, which can give rise to significant changes in the local and regional hydrogeological regime. Where the last colliery in an entire coalfield closes, these changes can be very large-scale and potentially damaging, with potential for pollution of major rivers and aquifers. While a number of modelling approaches have been developed in recent decades to predict these changes and facilitate their proactive (and prophylactic) management, when the last mine in a given coalfield is closing the mine owners typically have neither the time nor money to commission extended and sophisticated numerical modelling studies. In such circumstances, a simplified, lower-cost approach is required to provide regulators with predictions of rates of water level rise, future equilibrium water levels and the rates and quality of any future outflows of mine water to rivers and / or aquifers. These predictions can also be useful in guiding the decisions of future site owners over alternative uses of colliery infrastructure after the cessation of coal production. An approach to such predictions has been developed which is based on summary information on the extent of workings, dewatering pumping rates, locations and collar elevations of unfilled shafts and adits attached to the deep workings, as well as surface topography and the geometry of any overlying aquifers. Uncertainties over hydraulic gradient after the completion of water level recovery are handled by analogy to a range of postrecovery gradients from similar large coalfields. A brief example of the application of the approach to a real coalfield is presented. This approach could be used either on its own or as a prelude to more detailed modelling and monitoring during the years following mine closure. The insights into system behaviour gained from such exercises could well be valuable in future re-use of flooded voids as resources for heat recovery or disposal as part of low-carbon heating systems. Highlights• Prediction of the hydrogeological behaviour of abandoned coalfields • Quantifies the duration of flooding till rest water levels are reached • Identifies the mined features most likely to give rise to polluted outflows • Allows prioritisation of post-closure treatment of major shafts

show abstract

“…Today, after observations of recent coal mine closures, postclosure mine water management has become a critical element in mine permitting and design. Realistic prediction of the duration and timing of postclosure mine flooding and the locations of potential future surface discharge(s) are considered critical information for mine design and planning [7,9,10]. However, such predictions are hampered by uncertainties related to the same factors that have caused flooding to proceed differently within different mines.…”

Section: Introductionmentioning

confidence: 99%

Mine Flooding History of a Regional Below-Drainage Coalfield Dominated by Barrier Leakage (1970–2014)

Donovan

Perry

2019

Geofluids

View full text Add to dashboard Cite

A 44-year record of water level fluctuations in a series of adjacent closed underground mines documents the history of closure and mine flooding in the Fairmont Coalfield, one of the oldest coal mining districts in the Pittsburgh coal basin, West Virginia, USA. As closures proceeded and mines began to flood, US environmental regulations were first enacted mandating mine water control and treatment, rendering uncontrolled surface discharges unacceptable. The purpose of this study is to present this flooding history and to identify critical events that determined how mine pools evolved in this case. Also examined is the strategy developed to control and treat water from these mines. Flooding is visualized using both water level hydrographs and mine flooding maps with the latter constructed assuming mine water hydraulic continuity between one or more mines. The earliest flooding formed small pools within near-surface mines closed prior to 1962 yet still pumped following closure to minimize leaking into adjacent still-active workings. These subpools gradually enlarged and merged as more closures occurred and the need for protective pumping was removed, forming what is today referred to as the unconfined Fairmont Pool. Later, deeper mines, separated by intact updip barriers from the Fairmont Pool, were closed and flooded more gradually, supplied in large part by leakage from the Fairmont Pool. By 1985, all mines except 2 had closed and by 1994 all had fully flooded, with the Fairmont Pool interconnected to deeper single mine pools via barrier leakage. As protective pumping ceased, the Fairmont Pool rose to a water level 3 m higher than surface drainage elevation and in 1997 discharged from an undermined section of Buffalo Creek near the Monongahela River. The principal mine operator in the basin then designed a pumping system to transfer water from the Fairmont Pool to their existing treatment facilities to the north, thus terminating the discharge. It may be concluded that the progress of mine flooding was influenced by mining history and design, by the timing of closures, by barrier leakage conditions, and by geologic structure. A key element in how flooding proceeded was the presence of a series of intact barriers separating deep from shallow mines. The shallow mines closed and flooded early, but then lost sufficient water by barrier leakage into the deeper mines to delay the completion of flooding until after the deep mines had all closed and flooded as well. Intensive mine water control has continued from the 1997 breakout to the present. The final water control scheme was likely unanticipated and serendipitous; future district-wide mining efforts should be advised to consider in advance closeout strategies to control mine water postmining.

show abstract

Long-term water quality trends at a sealed, partially flooded underground mine

Cited by 15 publications

References 0 publications

Using Time Series Analysis of Coal Mine Hydrographs to Estimate Mine Storage, Retention Time, and Mine-pool Interconnection

Using Time Series Analysis of Coal Mine Hydrographs to Estimate Mine Storage, Retention Time, and Mine-pool Interconnection

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

Mine Flooding History of a Regional Below-Drainage Coalfield Dominated by Barrier Leakage (1970–2014)

Contact Info

Product

Resources

About