n||Production (million tons)||Average seam (inches)||Acres annually disturbed||Acres per million tons|
Sources: "Underground production by state and mining method, 2009," Energy Information Administration; "Longwall Mining," Table 4: Average Mining Height of Longwall Units, by State and Region, Energy Information Administration, DOE/EIA-TR-0588, March 1995. Note: Appalachia includes Alabama, Eastern Kentucky, Maryland, Ohio, Pennsylvania, Virginia, and West Virginia. Illinois Basin includes Illinois and Wesetrn Kentucky. West includes Colorado, New Mexico, Utah, and Wyoming.
Global longwall production
World coal production in 2009 is estimated at 5,990 million metric tons (5,348 million short tons) for hard coal and 913 million metric tons (815 million short tons) for brown or lignite coal. Worldwide, approximately half of coal production is produced via longwall mining, mainly due to the high proportion of Chinese mining performed using longwall methods. In China, underground mining accounted for 85.9% of total production in 2008. There are more than 20 underground coal mining methods in China, almost exclusively longwall. Applied to estimated 2009 production of 3,210 million short tons, the total amount of coal produced via longwall mining in China is 2,757 million short tons. In 2008, China's 268 national strategic mines operated 1,545 longwall faces and 4,808 development faces. Of these, 88.3% are mechanized.
Other countries with major amounts of longwall mining include:
- United States: The United States operates 49 longwalls producing over 175 million metric tons (156 million short tons) per year.
- Australia: China has 29 operating longwall faces producing 47.5 million tonnes (42.4 million short tons)
Longwall mining in Illinois
Mining companies are buying up land in Illinois from struggling farmers for longwall mining. In Litchfield, IL, Cline Mining Corp. began buying land, prepping the ground for mining but leaving it unusable. Removing the slabs after mining can lead to sinking on the surface, with some land sinking down 15 feet, causing damage to roads and formations of creeks in what was once profitable farmland. Yet as of 2010 Cline Mining continues to buy land from struggling farmers and its mining efforts are expanding, with new mines starting closer to Hillsboro. Many townspeople begrudgingly support the business. In a time when jobs are increasingly hard to find, the development of longwall mining in the area promises to bring jobs to many people in the area, despite the cost for others. While the more traditional practice of room-and-pillar mining could be used in the area instead, the practice takes considerably longer to set up and execute, and cannot extract as much coal.
Longwall mining in Pennsylvania
2010 Citizens Coal Council report on damage to PA water
In July 2010, the Citizens Coal Council (CCC) - a national alliance of social and environmental justice grassroots groups - released the results of a nine-month long investigation into the regulatory files of three major longwall mining operations in southwestern Pennsylvania: Bailey Mine (Consol Energy), Enlow Fork Mine (Consol), and Emerald Mine (Foundation Coal). Analyzing over 75,000 pages of Pennsylvania Department of Environmental Protection (PADEP) mining files, CCC found "an internal administrative quagmire of illogical permit monitoring, baseless decisions, and lax oversight of coal operators by the PADEP." The report finds that despite improved data collection requirements and strong state constitutional and regulatory safeguards, the PADEP has failed to adequately evaluate and protect against threats to Pennsylvania streams and watersheds adversely affected by the longwall “full extraction” method of coal mining. The report can be found here.
CCC said that while the report only focuses on the past several years of mining records, subsidence damage to streams and watersheds has been allowed by PADEP since Act 54 of 1994, which paved the way for widespread use of longwall mining in Pennsylvania. Communities impacted by longwall-related 