Passive Reactive Berm to Provide Low Maintenance Lead Containment at Active Small Arms Firing Ranges: Field Demonstration

Heavy metals are released into the environment as a result of critical military live-fire training. Preventing heavy-metal migration into and contamination of the local environment is crucial because remediating contaminated soils is resource intensive, difficult, and costly. Previous studies have demonstrated that phosphate amendments have been successfully used as a best management practice BMP to immobilize metal contaminants. The Passive Reactive Berm PRBerm technology incorporates phosphate amendments with ballistic sand to immobilize soluble metals e.g., lead during the inevitable bullet corrosion process. Treatability studies determined that an amendment ratio of 5 weight weight to sand was sufficient to contain 90 of soluble lead within the berm material. The technology was field tested on the M-60 small arms firing range SAFR at Charleston Air Force Base CAFB in Charleston, South Carolina. The CAFB PRBerm was tested with a 5 TRAPPS amendment a granular, apatite-based material, alone and in combination with a 5 thermally treated fish bone Apatite. For the CAFB PRBerm, storm water runoff and leachate water samples were collected directly from the SAFR and analyzed for metals, total suspended solids TSS, and pH. Reduced metals migration in soil leachate and surface water runoff when compared to the traditional earthen berm was observed. The total suspended solids in the leachate and runoff waters from the amended berms increased over the control berm. Results indicated that the pH of the runoff waters from the amended berms remained acidic. The benefits of the PRBerm when compared to the traditional earthen berm, or a fully contained bullet trap, include reduced metals migration in soil leachate and surface water runoff, as well as reduced construction and operation costs. The PRBerm has the potential to provide a useful, low-cost tool for defense forces to maintain active firing ranges.