The Joliet Army Ammunition Plant's Load-Assembly-Packing Area sits in Will County, Illinois, about 10 miles south of Joliet. The plant ran from the early 1940s through 1977, loading and packaging artillery shells, bombs, mines, and small arms ammunition. It was added to the National Priorities List (NPL) in 1989. The U.S. Army leads the cleanup as the site's owner and operator, with EPA and the Illinois EPA providing oversight under the federal Superfund law known as CERCLA (Comprehensive Environmental Response, Compensation, and Liability Act).
EPA identified 20 contaminants of concern across soil and groundwater. Explosive compounds such as RDX, HMX, and TNT are the main concerns, found in both soil and groundwater. Heavy metals including arsenic, lead, cadmium, beryllium, and copper were detected in soil. Polychlorinated biphenyls (PCBs), volatile chlorinated solvents, and total petroleum hydrocarbons were also found in soil. EPA determined all of these require cleanup based on the amounts present and risks to human health and the environment.
Cleanup work used several methods: bioremediation, excavation, incineration, landfill capping, and monitored natural attenuation of groundwater. EPA issued Records of Decision in 1998 and 2004 selecting these remedies. A 2018 Explanation of Significant Differences updated the approach for Landfill L3, and a time-critical removal action in 2015 and 2016 removed and disposed of its contents off-site. Construction finished in September 2008, three years ahead of schedule. A No Further Action decision was reached in 2019 for the L34 Munitions Response Site. The L2-L3 Munitions Response Site (Operable Unit 4) is still in the study phase, with a feasibility study expected to conclude between January and March 2028.
Human exposure is currently under control. EPA has found no unacceptable exposure pathways, and contaminated groundwater migration is stabilized with no unacceptable discharge to surface water. The site achieved sitewide ready for anticipated reuse status in 2011 and is now home to the Midewin National Tallgrass Prairie, Abraham Lincoln National Cemetery, Prairie View Landfill, and several business parks. Zoning and deed restrictions remain in place to limit land uses and prevent exposure to any remaining contamination. Semi-annual groundwater and surface water monitoring continues, along with regular landfill inspections. The most recent five-year federal facilities review was completed on August 21, 2024, and EPA completed its review of the Fifth Five-Year Review Report Addendum on September 11, 2025.
Community members with questions can contact EPA's Community Involvement Coordinator or Remedial Project Manager. Site documents are available through EPA's online collections, and a full Administrative Record copy can be requested through the lead federal agency or the site's Public Information Repository.
