Bottom ash

[3] Coal contains trace levels of arsenic, barium, beryllium, boron, cadmium, chromium, thallium, selenium, molybdenum, and mercury, many of which are highly toxic to humans and other life.

[4] Most U.S. power plants do not use geomembranes, leachate collection systems, or other flow controls often found in municipal solid waste landfills.

The EPA published its "Part A" final rule for Coal Combustion Residuals (CCR) on August 28, 2020, requiring all unlined ash ponds to retrofit with liners or close by April 11, 2021.

Some facilities may apply to obtain additional time—up to 2028—to find alternatives for managing ash wastes before closing their surface impoundments.

[6][7][8] EPA published its "CCR Part B" rule on November 12, 2020, which allows certain facilities to use an alternative liner, based on a demonstration that human health and the environment will not be affected.

[11] Bottom ash may be used as raw alternative material, replacing earth or sand or aggregates, for example in road construction and in cement kilns (clinker production).