The long and dirty story [1] of the fate of the toxic wastes from a Tennessee Valley Authority coal ash spill [2] in 2008 contradicts the idea that coal can be "clean [3]." The story also shows how difficult tracking the fate of such waste can be.
Links:
[1] http://news.yahoo.com/s/ap/20100306/ap_on_re_us/us_coal_ash_disposal
[2] http://www.epa.gov/region4/kingston/basic.html
[3] http://www.rtknet.org/db/tri/tri.php?dbtype=C&facility_id=37763STVKNSWANP&rsei=y&sortp=D&detail=-1&datype=T&reptype=f&reporting_year=&submit=GO