Study Of Quantitative Impacts To Ground Water Associated With Longwall Coal Mining At Three Mines Sites In The Northern West Virginia Area

Dixon, Denise Y.
Organization: International Conference on Ground Control in Mining
Pages: 15
Publication Date: Jan 1, 1988
The objectives of this study were to (1) document the hydrologic impacts of longwall mining on ground water, (2) identify the factors which affect the extent of dewatering, and (3) develop empirical trends to predict the extent of dewatering and recovery in advance of mining. The study was confined to three mine sites in north-central West Virginia. At each site, available ground water supplies were identified and monitored for dewatering effects and recovery. Mine A, located in Upshur County, West Virginia, has relatively thin overburden (approximately 715-280 feet). At this site domestic water supplies and specially constructed monitoring wells were monitored, continuing with an earlier study done by Cifelli arid Rauch. Most such supplies were completely dewatered over the longwall panel. Some of these wells have shown significant recovery, especially near a stream. Extensive monitoring of two nested piezometer wells revealed that dewatering generally started in advance of undermining in the lowermost monitored overburden zones first and then progressed upwards. Most dewatered wells completed in bedrock have shown no recovery, except. for valley drilled wells located within 100 feet of a Stream. Affected dug wells completed in valley alluvium rend located within 200 feet. of the nearest stream have shown significant recovery. Some wells have partially collapsed following mine subsidence. Mine B, having relatively thick overburden (approximately 585 to 900 feet), is located in Monongalia County, West Virginia. Ground water supply surveys have been conducted there in an attempt to study past dewatering effects. Owners reported Chat several wells were dewatered by longwall mining arid vertical air shafts that preceded longwall mining. Dewatered wells over longwall panels hove shown some recovery within 3 ½ years of mining. Mine C also has relatively thick overburden (approximately 585-900 feet), and is located mostly in Greene County, Pennsylvania. In addition to a survey of domestic water supplies at this site, five specially constructed monitoring wells were tested. The shallow monitoring wells suffered drops in water level due to mining but totally recovered within one day to three weeks after dewatering occurred. However, they did occasionally exhibit partial collapse during mine subsidence. Subsidence fracturing was beneficial in increasing the lateral hydraulic conductivity by a factor of about S to 22 for rock strata located within 124 feet of the surface, indicating enhanced shallow aquifer potential. One deep well suffered both partial dewatering and structural damage, with the state of water recovery bring uncertain. Also, two shallow domestic supplies out of five located over the mine were reportedly dewatered, but this claim could not, be substantiated.
Full Article Download:
(4461 kb)

Additional chapters/articles from the SME-ICGCM book Proceedings 7th International Conference on Ground Control in Mining (ICGCM) 7th

Field Evaluation of Yield Pillar System at a Kentucky longwa
In-Situ Pillar Strength Determination for Two-Entry Longwall
Integrity Factor Approach to Assess the Stability of Room-an
Longwall Recovery Utilizing The Open Entry Method And Variou
Design Of Lower Seam Longwall Operations In Multiple Seam Mi
Method Of Selecting Suitable Types Of Powered Supports At Lo
An Overview Of The National Roof Evaluation Accident Prevent
Strata Control Advances At Jim Walter Resources, Mining Divi
Portal Stability In Rock
Bailey Mine Slurry Impoundment Longwall Subsidence Monitorin
Prediction Of Surface Subsidence And Strain In The Appalachi
Computerised Subsidence And Displacement Prediction Using In
Computer Modeling Of Yield Pillar Behavior Using Post-Failur
Practical Rock Mechanics For Safety And Productivity Improve
Geotechnical Mine Design Of The Foidel Creek Mine
A Hydrogeomechanical Study Of Overburden Aquifer Response To
Comparison Of Predictions And Measurements Of Subsidence Cau
RYBAD Empirical Field Model For Prediction Of Maximum Land S
Mining Under Strong Roof
Sub-Surface Ground Movements Associated With Longwall Mining
A Computer Simulation Of Breakage Of The Main Roof In Longwa
Evaluation Of Low-Coal ATRS Systems
Analysis Of Major Failure Through Integration Of Static And
Outbursts And Rockbursts In Coal Mines
Analysis Of The Initial Collapse Of The Overburden Over Long
The Influence Of Stream Valleys On Coal Mine Ground Control
Aerostatic Support System For Underground Coal Mines
A Simplified Two-Dimensional Analysis Of The Roof-Pillar-Flo
Comparative Studies In The Mechanics Of Grouted Roof Bolts
Seismic Studies Over Active Longwall Mines
Surface Ground Movements Over Longwall Mining In The Pittsbu
Effect Of Longwall Mining Subsidence On The Stability Of Sur
Study Of Quantitative Impacts To Ground Water Associated Wit
The Broken Rock Zone Around Tunnels And Its Support Theory
Subsidence In Indian Coalfields
Case Studies Of Depillaring Under Special Strata And Mining
The Control Of Surface Subsidence By Width/Depth Ratio And C
Design Of The Ventilation Shaft In The South Link Railway Tu