Hennepin Power Station has 41 groundwater monitoring wells, 27 of which have been polluted above federal advisory levels based on samples collected between March 16, 2010 and September 18, 2019. Groundwater at this site contains unsafe levels of molybdenum, boron, lithium, cobalt, arsenic, nitrate, cadmium, selenium, manganese and sulfate.Site description
Hennepin Power Station was a 306-MW peak capacity facility with two coal-fired units, first built in 1953 in Hennepin, Illinois in Putnam County. The plant was owned by Dynegy. In 2018 Dynegy merged with Vistra Energy, who closed the facility in 2019. Havana had three ash ponds, a landfill, and a polishing pond regulated under the CCR rule. Hennepin reported the on-site release of 274,615 pounds of waste to the EPA's Toxic Release Inventory. Dynegy settled with the Department of Justice, Environmental Protection Agency, and the State of Illinois in 2005 after violating Clean Air Act permitting provisions. The settlement most notably included the installation of $500 million worth of pollution control equipment. Havana Power Station, Baldwin Power Station, Vermilion Power Station, and Wood River Station were also involved in this settlement. Hennepin Power Station was listed among the U.S. EPA's proven damage cases, indicating that it has polluted groundwater or surface water at levels which threaten human health and the environment.