How is an underground coal mine defined?

An underground coal mine is defined as areas used for underground excavation and related facilities because it encompasses not just the active mining areas but also all supporting structures and spaces associated with the mining operation. This includes tunnels, shafts, and drifts where coal is mined, as well as facilities that may be needed for transportation, ventilation, and ensuring safety during the extraction process.

The other options are too narrow in their definitions. Focusing only on the working face of extraction fails to account for the infrastructure necessary for the overall mining operation. Similarly, limiting the definition to just surface facilities overlooks the significant underground components that are intrinsic to coal mining. Lastly, defining it strictly as areas for temporary storage of coal does not capture the extensive and complex nature of an underground mining operation, which involves extraction as well as overall mine management.