Milan Army Ammunition Plant

Overview

Milan Army Ammunition Plant covers 22,357 acres southeast of Milan in western Tennessee. It has produced and stored munitions since 1942. The EPA added it to the Superfund National Priorities List in 1987 because decades of munitions production and waste disposal contaminated the soil and groundwater. The site remains an active military installation, and the Army, EPA, and Tennessee Department of Environment and Conservation work together on cleanup.

The main contaminants are explosives and their byproducts, including HMX, RDX, TNT, and various dinitrotoluene and trinitrobenzene compounds. These are found in groundwater and soil across multiple areas. Metals such as arsenic, beryllium, cadmium, chromium, manganese, copper, and thallium are present in the southern study area. Other contaminants include carbon disulfide, chloroform, nitrate, nitrobenzene, and bis(2-ethylhexyl)phthalate. Unexploded ordnance is also a concern in the southern study area. Contaminated groundwater in the Memphis Sand Aquifer is the primary ongoing media of concern.

The Army completed three pump-and-treat systems between 1995 and 2002 to pull contaminants out of groundwater. Soil caps were built across multiple areas starting in 1995, with more caps added at the Open Burning Ground in 2011. Construction of the overall cleanup was completed on July 25, 2017. The site achieved sitewide ready for anticipated reuse on September 27, 2018. A sitewide groundwater extraction and treatment program is projected to restore the aquifer to drinking water standards by 2074. The Army is currently optimizing the extraction system and adding ultraviolet treatment to improve contaminant control.

In 2025, the EPA determined that soil remedies are protective of human health and the environment in the long term. Groundwater remedies are only short-term protective because contaminant concentrations are rising in some source areas and cleanup is moving slower than expected. Human exposure is currently under control, and contamination does not pose a threat to on-site workers, nearby residents, or businesses. Land use controls restrict access to contaminated areas, prohibit residential groundwater use, and limit the site to non-residential purposes. The City of Milan has also adopted ordinances restricting private water supply and requiring warning labels on nonpotable water sources.

The Army, EPA, and TDEC hold annual public meetings in Milan to update residents on cleanup progress. The first meeting was held on September 10, 2015. Public notices and interviews are also part of community outreach. Residents can get information on upcoming meetings by contacting the MLAAP Restoration Project Manager at the Post. Public information repositories are located at the Mildred G. Fields Memorial Library at 1075 A East Van Hook Street, Milan, TN, and at Milan Army Ammunition Plant at 2280 Highway 104 West, Suite 1, Milan, TN. Many records are also available online at www.milanaap-ar.com.