Longwall mining is a deep mining technique capable of fully extracting huge panels of coal, frequently up to 1,500 feet wide and two miles long. Coal shearing machines known as “continuous miners,” remove a long wall of coal in a single slice as hydraulic jacks hold up the roof above and in front of the machine. Once this coal (often 400-1,000 feet below the earth’s surface) is extracted, the continuous miner and hydraulic jacks advance, and overlying rock collapses into the void behind, leaving no support for the ground above the panel.

Coal companies that practice longwall mining are allowed, by law, to cause damage to structures, including homes.  They are also allowed to disrupt water supplies to homes and livestock.  Coal companies are required to pay for repairs to homes and to replace water supplies, but, frequently, residents find themselves embroiled in lengthy battles with these companies to have their living conditions restored.  

Often, companies will simply offer to buy a homeowner’s property and house either before undermining (when they realize there is a high risk of significant damage), or after there has been significant damage due to mining, whether directly underneath or nearby. This practice has resulted in a systematic depopulation of areas where longwall mining has occurred. If these people want to stay in the region they have two options: (1) to purchase another home in the area that could be undermined in the future, and then repeating this process again, or (2) to purchase a home that was undermined years ago, which may have some lingering issues, and could potentially suffer more damage in the future from subsidence. Both of these options are complicated by the fact that houses in the area rarely go up for sale and many houses are already owned by a coal company, meaning they are seriously damaged and off the market permanently.


Five counties in Pennsylvania have experienced longwall mining so far, but Washington and Greene are the only two counties with active and pending longwall mining permits today. Today most bituminous underground coal production in Pennsylvania is from longwall mining. This practice directly impacts our personal health and that of our surrounding environment.

Report prepared in connection with Act 54, the state law that regulates bituminous coal mining in Pennsylvania, reveal the devastating effects of coal mining generally and longwall mining in particular. The most recent report found the the 46 bituminous coal mines in the state undermined a total of 31,343 surface acres between 2008 and 2013 through both longwall and room-and-pillar methods. Approximately 40% of that undermined acreage is within Greene County, and 19% in Washington County. During that same time, nearly 200 miles of streams were undermined and about 77% of the miles of those streams experienced flow loss, pooling (formation of pools inside the stream banks where the stream should be flowing consistently) or both. Visit our Act 54 Campaign Page for more information on the damages and actions to protect our communities


  • Subsidence: the shifting of the earth above a coal mine after the coal has been removed, causing structural damage to homes, buildings, roads, and railways.

    • In 2006, 1-79 was undermined fourteen times, and traffic has been restricted on I-70 and PA Turnpike 43 due to subsidence.

  • Ponding: as a result of subsidence, wetlands are frequently created in areas that were previously dry.

  • The release of methane gas into the atmosphere, water and homes.  At least one home explosion has been documented as a result.

  • Ground cracks and landslides: frequently these render the land unusable.

  • Damage to homes, including cracking, buckling, and leaning

  • Disturbance to the water table  responsible for loss of water to homes and businesses and for the drying up of numerous wells, springs, and streams.

  • Creation of slurry impoundments, catch ponds for the water used to wash coal.  They frequently contain arsenic, mercury, and other toxic elements.

  • Depopulation of rural areas in the coalfields where longwall mining has occurred.


Are you directly impacted by longwall mining? Is there proposed longwall mining infrastructure in your community? Contact us at 724-229-3550 or email us at info@coalfieldjustice to see how we can support you.