Knoxville News Sentinel: Dredging the fly ash spilled into the Emory River from a Tennessee Valley Authority power plant could release selenium into the water with devastating effects on fish populations, a pair of scientists warn. TVA received approval for the initial phase of its dredging plan last week from the Tennessee Department of Environment and Conservation. Roughly 5.4 million cubic yards of the coal combustion waste flooded the river and surrounding countryside when a retention pond at the …