9781422285534

52 Coal

is also the case for surface mining. Preventing subsidence, or sinking, is far from an

exact science, but again modern geology studies can make it far less likely.

Water pollution from coal mines is also a difficult issue. Most underground mines,

and even some surface sites, are below the water table. As the water in the rocks,

called groundwater, slowly moves through them, the action of chemical changes and

bacterial microbes may make it acidic. This may only be detected years later, when the

mine is closed. The polluted water can eventually reach the surface, nearby or even

far away, and damage

watercourses

, wildlife, and habitats. This acid mine drainage

(AMD) is much reduced with modern methods, but it has left lasting scars in many

older mining regions. A similar problem comes from old surface piles of coal waste

tips, spoil, tailings, and similar leftovers.

Safety Concerns

The bad old days of frequent, large-scale mining disasters are largely in the past, at

least in North America. The greatest dangers were from collapse and the dreaded

firedamp, or methane. Undetected by human eyes, ears, or noses, this gas can seep out

of the walls and collect in pockets. If it reaches a proportion of 5 to 15 percent in the

This photo, taken

in Logan, West

Virginia, in 1974,

shows a massive

spoil heap burning

just a short

distance from the

miners’ homes.

Modern companies

try to do a better

job handling the

leftovers of coal

mining, but spoil

remains an issue.