Joliet Generating Station No. 29 has 11 groundwater monitoring wells, 7 of which have been polluted above federal advisory levels based on samples collected between December 06, 2010 and November 07, 2019. Groundwater at this site contains unsafe levels of cobalt, manganese, sulfate, antimony, nickel, cadmium and lead.Site description
Midwest Generation's Joliet 29 is a 1,320-MW capacity power facility in Joliet, Illinois in Will County, first built in 1965 along the Des Plaines River with two coal-fired units. Both units were converted to run on natural gas in 2016. The land surrounding the plant is primarily industrial or undeveloped, and according to Midwest Generation's Hydrogologic Assessment Repirt, industrial sites are located upgradient from some of the monitoring wells. Three active ash ponds are operated on the site and occupy 10 acres, regulated under the CCR rule. Two ponds have synthetic liners and the third is lined with a geo-composite material on the bottom. Seventeen potable and industrial use wells are located within 2,500 feet of the ash ponds (as of 2009), two of which are designated downgradient of the ash ponds. Both wells are owned by Midwest Generation and extend below a layer of soil that prevents water from entering the lower aquifer.