Marion Power Plant has 9 groundwater monitoring wells, 1 of which have been polluted above federal advisory levels based on samples collected between March 24, 2010 and September 13, 2011. Groundwater at this site contains unsafe levels of boron and cadmium.Site description
Southern Illinois Power Cooperative's Marion Power Plant is a 260-MW power plant first built in 1963 in Marion, Illinois on Lake of Egypt in Williamson County. The plant consists of a 120-MW coal-fired unit and two 70-MW natural gas or oil-powered units. An additional 173-MW coal-fired unit was retired in 2020. Coal fly ash, bottom ash, and flue gas desulfurization sludge have been placed in six unlined ponds, one unlined landfill, and one lined pond regulated by the CCR rule. Groundwater monitoring has been required near the landfill and ponds since 1994, and high concentrations of cadmium were first detected in 1997.