Remediation of inorganic and organic contaminants in military ranges

Environmental context Contaminants occur in the soil and water associated with military ranges. This review article describes how the extent of contamination depends not only on the type of military range and its period of activity, but also on the chemistry of both the soil and the contaminant. A full understanding of the soil chemistry is necessary to develop effective remediation methods for the restoration of these impacted environments. Abstract This review discusses the contaminants associated with military ranges and the approaches taken to remediate these sites. The type and extent of contamination depends on the type of range, period of activity, soil chemistry and contaminant chemistry. Small arms firing ranges typically have high concentrations of metals and metalloids whereas military ranges typically have high concentrations of perchlorates, white phosphorus, explosives and propellants. For explosives, higher concentrations are found in sites that have undergone a low order detonation than in sites with a high order detonation. Remediation technologies for small arms firing ranges include leaching and immobilisation whereas for military ranges, methods such as alkaline hydrolysis, photolysis, bioremediation and phytoremediation have been tested. A lot of work has been done to immobilise metals/metalloids using soil amendments, which show a high effectiveness in stabilising them. Some of these amendments, however, also mobilise other co-contaminants. More studies are needed to simultaneously immobilise all inorganic contaminants. Explosives can be transformed into simpler non-toxic forms by photolysis, bioremediation or phytodegradation. The introduction of bacteria transgenes into plants has been used to enhance uptake and degradation of explosives in transgenic plants. Adoption of appropriate remediation technologies in impacted military ranges will reduce contaminant levels and protect public health.