Coal combustion wastes as material for artificial reef construction

The projected conversion of oil-fired power plants to coal in the northeast raises the problem of disposing of the scrubber sludge and fly ash which will constitute 25 to 40% of the bulk of coal combusted at these plants. The Coal Waste Artificial Reef Program (C-WARP) has been initiated to study the environmental acceptability of using these waste materials for construction of offshore fishing reefs. The wastes are consolidated into stable blocks and cured to hardness for transport to disposal sites. In the summer of 1980, 500 tons of stabilized coal wastes were processed into about 15,000 blocks at a commercial concrete block factory and cured in steam kilns. The blocks were taken to sea by barge on 12 September 1980 and released at a site off Long Island, New York to form a demonstration reef. Biological colonization has been successful and a diverse community of invertebrates and fishes has inhabited the reef. Physical properties of the blocks have been monitored at sea using non-destructive ultrasonic techniques and by evaluation of retrieved blocks in the laboratory for structural integrity. Other investigations are assessing chemical and biological compatability with the marine environment.