Flue gas desulfurization sludges and fly ash pose a major disposal problem for coal-burning power plants. Disposal of stabilized, blocklike forms of these wastes in the ocean in the form of a reef is an alternative being studied at the Marine Sciences Research Center, Stony Brook, N.Y.

In laboratory experiments, physical integrity studies and components species leaching rates indicate that, in general, stabilization was found to maintain the strength of the blocks and minimize trace metal leachings in aerobic seawater over prolonged exposure.

In field studies, which are in progress, nine blocks (0.028 m³) of stabilized scrubber sludge and fly ash were placed in approximately 6 m of water in Conscience Bay near Long Island Sound. Within 3 weeks after placement of the coal waste reef and the control structure, a heavy crop of attached plants and animals were observed growing on both reefs. The organisms attached to the coal waste reef showed no elevation in heavy metals in relation to the heavy metal composition of organisms attached to the concrete control.