Will County Generating Station has 12 groundwater monitoring wells, 12 of which have been polluted above federal advisory levels based on samples collected between December 13, 2010 and December 06, 2019. Groundwater at this site contains unsafe levels of boron, sulfate, manganese, molybdenum, arsenic, antimony and selenium.Site description
Will County Generating Station was a 598-MW capacity power plant with four coal-fired units, located east of Romeoville, Illinois in Will County and operated by Midwest Generation. The facility was first built in 1955 and was retired by its owner (NRG) in June 2022. Will County has four ash ponds situated between the Des Plaines River (with Ash Ponds 2/3 regulated by the CCR rule), the Chicago Sanitary and Ship Canal, a quarry, and undeveloped land. Shallow groundwater flow at the site fluctuates toward either the Des Plaines River or the Chicago Sanitary and Ship Canal, while deeper groundwater tends to flow toward the southeast. The site is also located within an area where groundwater is depressed due to excessive groundwater withdrawals for other purposes. As of 2009, one potable water well was located within 2,500 feet of the ash ponds. Routine groundwater monitoring at the site began in 2011.
In October 2012, Midwest Generation entered into a Compliance Commitment Agreement with the Illinois Environmental Protection Agency (IEPA) to address violations of groundwater standards at Will County Generating Station. Among other requirements under this agreement, the ash ponds at the site were not to be used as permanent disposal facilities, two of the site s four ash ponds would be closed, one ash pond would have to be re-lined, and the facility had to apply for and establish a Groundwater Management Zone and an Environmental Land Use Control designation for portions of the site.