MILAN, Tenn. -- On July 31, 2014, the U.S. Army, U.S. Environmental Protection Agency, and the Tennessee Department of Environment and Conservation jointly signed a Record of Decision for the cleanup of explosive-contaminated groundwater on Milan Army Ammunition Plant.
The agreement completes 30 years of environmental investigations and will continue operation and maintenance of two groundwater treatment plants with a groundwater monitoring program.
Because of the agreement, treatment and monitoring can proceed with criteria identified in advance by the Army, USEPA, and TDEC, eliminating time-consuming reviews and approvals, while reducing costs to the taxpayers. The active treatment of the groundwater is expected to continue for the next 15 years with continued monitoring thereafter at a cost of $26.5 million. This plan reduces life-cycle costs over the 60-year clean-up timeframe.
In 2012, the Army, USEPA, TDEC, and the community Restoration Advisory Board agreed on a strategy to implement one comprehensive cleanup plan for all groundwater plumes from Milan AAP.
This site-wide groundwater ROD implements a decision making process that is flexible and reliable. USEPA Region 4 presented Milan AAP's approach during an internal seminar as a tool that could be used at similar sites across the country. Based on the innovative decision-making process involved, Milan AAP applied for the 2013 Secretary of the Army Environmental Award for the clean-up program and was runner-up in the competition.
The primary challenge with site-wide groundwater cleanup at Milan AAP is the scale of the groundwater plumes. They currently extend more than 4,500 acres (approximately seven-square-miles). In addition to the active treatment of groundwater by the Army, naturally occurring bacteria in the ground help eliminate the explosive compounds. All areas of the groundwater plume are evaluated annually to determine if treatment needs to be redirected toward different areas.
Based on the draft ROD, Arcadis, the environmental contractor hired by the Army, was tasked in 2013 to expand the groundwater extraction system to include the remaining plumes. This work began in January 2014 and was completed in May 2014. Environmental Chemical Corporation is now under contract with the Army for the next five years to operate and maintain the groundwater treatment systems.
Beginning in the 1940s, contamination from explosives was released into the environment at Milan AAP from production processes and treatment of munitions. The contamination impacted the soil and groundwater on Milan AAP. Groundwater migrated off-post to the north and northwest onto some private properties and within the City of Milan. Contaminated groundwater impacted the City of Milan water wells in the late 1980s and was significant enough for the Army to finance the construction of new water supply wells for the City of Milan. Due to the groundwater contamination, Milan AAP was listed as a superfund site in 1989.
The Army began investigating waste releases from Milan AAP in the late 1970s. The Army ceased releasing contaminated water from production lines in the 1980s. Extraction of contaminated groundwater for treatment was first implemented in 1992 at the O-Line Ponds area with the construction of a groundwater treatment plant. Two more groundwater treatment plants were constructed in 2000 and 2002 to capture and treat groundwater moving off-post toward the City of Milan and northward toward private property. Although these plants treated water from the high priority areas, groundwater was not treated at other areas within Milan AAP. The new agreement addresses all areas of the plume with priority on off-post contamination and areas of highest explosive concentrations.
Milan Army Ammunition Plant is an installation of the Joint Munitions Command. Milan AAP maintains a production-ready ammunition plant and on-order ammunition for the Joint Warfighter. JMC is the logistics integrator for life-cycle management of ammunition and provides a global presence of technical support to U.S. combat units wherever they are stationed or deployed.
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