Safe Disposal of Coal Combustion Residuals

Coal combustion residuals (CCR) are regulated by the State of Michigan and the Resource Conservation and Recovery Act (RCRA). Examples of CCR include fly ash and bottom ash (see picture below), 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 and includes flue gas desulfurization material such as lime. 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.

Coal Residuals


CCRs are collected and placed in a disposal facility that is licensed and inspected by the Michigan Department of Environmental Quality (MDEQ). Disposal facilities have an engineering plan, groundwater monitoring program, closure plan, and financial assurance that has been reviewed and approved by the MDEQ. Plant staff conduct daily inspections of the disposal facility and third-party professional engineers inspect all facilities for safety and stability at least every three years. Additionally, MDEQ makes quarterly visits to conduct compliance inspections.

Consumers Energy has been implemented several measures to improve the management of our disposal facilities.

  • The fly ash handling systems at each of the five coal-generating facilities were converted to dry systems in 2009, greatly reducing wastewater, which contributes to greater protection of the environment.
  • Consumers Energy has been converting historical surface impoundments that manage hydraulically transported ash in dry landfill facilities that mechanically place ash.
  • The final cover systems have been evaluated and improved for each of the disposal locations to reduce infiltration from precipitation and more efficiently convey storm water to permitted outfalls.

Upon closure of disposal facilities, 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 will then be initiated, including inspecting the final cover, maintianing the vegetation, and completing noted maintenance. Groundwater monitoring programs will continue during this post-closure care period to ensure compliance with water quality standards. Finally, a land use restrictive covenant will be maintained to assure property restrictions for a period of 50-years once the closure has been certified with the MDEQ.

Updated April 2015

dry ash storage field

Aerial view of dry coal ash storage.