SERDP 2015 Project-of-the-Year Award for Environmental Restoration
(Initially Released December 7, 2015) Soil contamination is a concern at many firearms training facilities. Lead is the primary metal of concern, as it makes up approximately 90% by mass of a typical bullet and is a common constituent in rockets, mortars, grenades, and Howitzer rounds. In addition to lead, a number of other potentially toxic trace metals and metalloids are of concern. Bullet alloys generally include antimony, arsenic, bismuth, and silver, and bullets are commonly encased in a copper or nickel jacket. Fragments of bullets and other munitions are highly susceptible to oxidation and weathering processes in soil systems, leading to the release of aqueous metal or metalloid species into soils. The potential for metals or metalloids stored in soils to migrate from shooting ranges into surface or subsurface aquatic systems is a public health concern.
Dr. Thomas Trainor of the University of Alaska Fairbanks and his team have conducted an in-depth analysis of the changes in lead and antimony speciation that occur over time in range soils. They constructed shooting range impact berms to observe the progression of metal oxidation and track the evolution of mobile species that form as a result of fragment weathering processes under field conditions. From this, they determined the efficacy of soil amendments to reduce metal and metalloid mobility and developed surface-specific analytical tools to complement traditional geochemical analytical methods. The team is now completing studies that will further the understanding of the factors that control the mobility and speciation of lead and antimony in soils, enhance the use of passive sensors and surface-specific speciation methods, and test promising remediation scenarios based on cost-effective chemical amendments of the soils.
The results of this study have improved the understanding of lead and antimony mobility through range soils. This comprehensive understanding of the processes controlling mobilization versus retention of species associated with bullet fragment weathering in small arms training range soils is essential for assessing long-term environmental risk, for understanding the efficacy of remediation scenarios, and for identifying what materials to incorporate into future training range or impact area designs. This work will lead to technical guidance for range managers and regulators to monitor geochemical conditions pertinent to weathering of spent ammunition in soils and surrounding environments.
For this important work, Dr. Trainor and his project team received the 2015 SERDP Project-of-the-Year Award for Environmental Restoration. Project Overview