Coal is a fossil fuel formed from the decomposition of organic materials that have been subjected to geologic heat and pressure over millions of years. Coal is considered a nonrenewable resource because it cannot be replenished on a human time frame.The activities involved in generating electricity from coal include mining, transport to power plants, and burning of the coal in power plants. Initially, coal is extracted from surface or underground mines. The coal is often cleaned or washed at the coal mine to remove impurities before it is transported to the power plant—usually by train, barge, or truck. Finally, at the power plant, coal is commonly burned in a boiler to produce steam. The steam is run through a turbine to generate electricity.Although power plants are regulated by federal and state laws to protect human health and the environment, there is a wide variation of environmental impacts associated with power generation technologies.The purpose of the following section is to give consumers a better idea of the specific air, water, solid waste, and radioactive releases associated with coal-fired generation.pollutants build up in the water used in the power plant boiler and cooling system. If the water used in the power plant is discharged to a lake or river, the pollutants in the water can harm fish and plants. Further, if rain falls on coal stored in piles outside the power plant, the water that runs off these piles can flush heavy metals from the coal, such as arsenic and lead, into nearby bodies of water. Coal mining can also contaminate bodies of water with heavy metals when the water used to clean the coal is discharged back into the environment.The burning of coal creates solid waste, called ash, which is composed primarily of metal oxides and alkali. On average, the ash content of coal is 10 percent. Solid waste is also created at coal mines when coal is cleaned and at power plants when air pollutants are removed from the stack gas. Much of this waste is deposited in landfills and abandoned mines, although some amounts are now being recycled into useful products, such as cement and building materials.