Utilizing coal to produce electricity creates fly ash and bottom ash, also known as coal combustion residuals (CCR). Fly ash is comprised of tiny particles removed from our flue gas by emissions control devices. Bottom ash is made up of larger particles, such as sand and small rocks within the coal, collected in the bottoms of boilers.
We have been proactive in our ash management for many years. All of the company’s fly ash handling systems have been converted to dry systems. Dry systems reduce the amount of water entering the landfill and significantly reduce the potential to release contaminants into the environment.
100 percent of Consumers Energy’s bottom ash (approximately 100,000 tons annually) is used to manufacture Portland cement or to replace native materials in landfill construction. About 25 to 30 percent of our fly ash (up to 125,000 tons annually) is used in ready-mix concrete or in Portland cement manufacture.
All of our fly ash that is not beneficially used is disposed of in landfills permitted and inspected by the Michigan Department of Environmental Quality (MDEQ). Bottom ash is temporarily stored in surface impoundments which are inspected by the MDEQ and third-party registered professional engineers to ensure safe and reliable operation.
All of our disposal facilities are subject to water quality monitoring requirements under MDEQ approved hydrogeological monitoring plans. However, groundwater monitoring requirements are waived at the JR Whiting Land Disposal Facility based on a successful demonstration to the MDEQ that geological conditions preclude contamination from entering the underlying aquifer.
Closure plans for all disposal facilities are also approved by the MDEQ. To ensure disposal unit closure performance, Consumers Energy maintains a $1 million bond for each area with the MDEQ as a beneficiary and maintains a perpetual care fund with defined contributions made each quarter. Finally, closed landfills will be monitored for at least the next 30 years to ensure environmental protections are maintained.
Updated October 2013