Safe Disposal of Coal Combustion Residuals

Coal combustion residuals (CCR) consists of fly ash and bottom ash, which are generated when coal is used to produce electricity. 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, and is collected at the bottom of the boilers.

CCR materials are collected and placed in a Michigan Department of Environmental Quality (MDEQ) permitted and inspected disposal facility. Each disposal facility has an engineering plan, groundwater monitoring program, closure plan, and financial assurance that has been reviewed and approved by the MDEQ. Additionally, MDEQ makes quarterly visits to conduct compliance inspections, and a third-party professional engineer inspects all facilities for safety and stability at least every three years.

Consumers Energy has been taking proactive measures to manage our disposal facilities for many years. The fly ash handling systems at each of the five coal-generating facilities have been converted to dry systems, greatly reducing wastewater; which in turn contributes to greater protection of the environment. Consumers Energy has been converting historical surface impoundments that managed hydraulically transported ash into dry landfill facilities that mechanically place ash. Additionally, the final cover systems have been evaluated for each of the disposal locations to reduce infiltration from precipitation and more efficiently convey the storm water to permitted outfalls.

When disposal facilities are closed, Consumers Energy will receive certification from the MDEQ that the facility is in compliance with the approved closure plans. A 30-year post-closure care period is then implemented where the final cap overlying the disposal area is inspected, the vegetation is maintained, and any defects are repaired. Groundwater monitoring continues during this post-closure care period to verify compliance with water quality standards. Finally, a separate land use restrictive covenant will be executed with each county to assure property restrictions and maintenance for a period of 50-years once the closure has been certified with the MDEQ.

Updated April 2014

dry ash storage field

Aerial view of dry coal ash storage.