During construction of the turbine foundations and burying cable, sediment can become disturbed for a brief time period, but it then settles out and returns to the bottom. Researchers at Case Western Reserve University are studying the content and characteristics of sediment and will continue to advise LEEDCo on their findings.
Considering the Great Lakes Compact, another benefit of offshore wind energy is the non-consumptive nature of the Great Lakes' freshwater resource. Coal and nuclear power plants, on the other hand, use substantial quantities of water for their cooling systems, and discharge warm water into the lake. The report by the Great Lakes Commission, "Examination of Future Power Generation Scenarios and Water Resource Impacts," indicates each kilowatt-hour generated from coal (86% of Ohio generation) requires an average of 25 gallons of water.
Coal-fired power generation is responsible for mercury deposition in the lakes. The Natural Resources Defense Council published a report called "Poisoning the Great Lakes: Mercury Emissions from Coal-Fired Power Plants In the Great Lakes Region" which more widely explores these issues. In fact, Ohio accounts for 21 percent of the total mercury emissions from power plants in the eight Great
Lakes states. There are roughly 144 coal-fired power plants in the region, according to the NRDC report.