PRO-ACT Factsheet on Lead Contamination In Soil at Small Arms Firing Ranges

This document was provided by PRO-ACT. Contact information is provided at the end of each document.

Introduction

Outdoor small arms firing ranges for weapons training are essential to the mission of many U.S. Air Force (USAF) facilities. Their use, however, often produces an undesirable environmental condition - lead contaminated soil. This becomes a problem when the range requires remediation and the soil becomes a hazardous waste. The need for remediation can result either from maintenance activities or closure of a range.

Remediation of Firing Ranges

Under Resource Conservation and Recovery Act (RCRA) regulations, lead is a characteristic hazardous waste. Thus the remediation of lead contaminated soil at a firing range, either for maintenance or site closure, does not significantly differ from any other soil remediation project. EPA Region VIII recently developed draft guidelines for remediation of rifle and/or pistol ranges. These guidelines have not yet been sanctioned by EPA Headquarters, but they do provide a good guide to small arms range soil remediation. One note - prior to beginning, you should consult both your Regional EPA and your State environmental agency to determine if there are local specific guidelines which you must follow.

The EPA Region VIII guidelines stipulate the following procedures for remediation of a small arms firing range:

Prior to beginning remediation, submit a sampling and analysis plan (SAP), a health and safety plan (HSP) and a waste analysis plan (WAP) to EPA for approval. After approval remediate using the following steps:

1. Sift munitions fragments from the impacted soil. These fragments can be recycled offsetting part of the remediation cost. The lead fragments also meet EPA's hazardous waste exemption for recyclable materials (40 CFR 261.6) and are exempt from most hazardous waste reporting and management requirements (40 CFR 266, Subparts C through H);
   
2. After sifting is complete, sample and analyze the impacted soil in accordance with the SAP and the WAP to determine if the leachable lead level in the soil is at or above the EPA level of 5 mg/L or a lower level set by the State. If it is, the soil is a hazardous waste;
   
3. If all samples reveal lead concentrations below Federal or State levels, the soil is not a hazardous waste and can be reused onsite, disposed of as nonhazardous waste or returned to its original location for reuse.

Treat or dispose of the hazardous waste. Several options are presented below:

1. Treatment/Disposal Options
   
   1. Ship to Treatment, Storage or Disposal Facility: If the soil from the firing range is a hazardous waste, it can be shipped to a treatment, storage or disposal facility. In accordance with RCRA land disposal restrictions, soil which is a characteristic hazardous waste due to lead contamination must be placed in a hazardous waste landfill. Therefore, sifting fragments for recycling can reduce the cost of disposal by allowing burial in a solid waste landfill, providing leachable lead does not exceed 5 mg/l.

   2. Onsite Stabilization and Solidification: Stabilization and solidification involves adding ingredients to fill in porous spaces in the soil and coat the soil grains. This technology appears to effectively immobilize contaminants in the soil, resulting in a dense, secure material. Several techniques for stabilizing and solidifying contaminated soils exist, each of which should be evaluated with respect to pertinent environmental factors in the area. One of the most common is cement stabilization. If these processes are performed onsite, the regulations of the state where the site is located may require a RCRA permit. Once stabilized, the mixture should be analyzed to insure it is still not a hazardous waste. If it isn't, it can be either granulated and reused or placed in a solid waste landfill.

   3. Soil Washing: A new soil washing process, developed by COGNIS of Santa Rosa, California, has successfully reduced soil lead concentrations at a U.S. Army (USA) Superfund site to background levels. (The USA had previously burned scrap ammunition and powder and buried shell casings at the site, resulting in soil lead concentrations as high as 86,000 ppm.) After sifting the soil and dividing it into gravel, sand and munitions particles, COGNIS technicians wash the soil in an aqueous acid solution to remove the lead. While the process is speedy and cost effective, it is proprietary to COGNIS and the spent acid solution requires treatment and disposal as a hazardous waste.

2. Contamination Prevention Techniques: The best method to prevent lead contamination of soil at firing ranges is use technologies which eliminate the problem. One of these is munitions traps which capture spent munitions and prevent their contact with the soil. Another is the use of lead-free ammunition.
   1. Upward Deflecting Backstop: An upward deflecting backstop is an angled metal impact plate that reduces the velocity of munitions. The impact plate deflects munitions particles upward into a swirl chamber. The munitions particles then fall into a tray at the base of the trap and are collected. While upward deflecting backstops are the most commonly used munitions traps at firing ranges, the backstop fragments munitions and produces airborne lead dust, which may contaminate adjacent soil areas.

      (PRO-ACT has been informed that Seymour Johnson AFB has installed an upward deflecting backstop at its firing range. Contact Mr. Tim Brecheen at (919) 736-6690 for more details.

   2. Rubber Munitions Trap: A rubber munitions trap consists of multiple rubber strips hung from a frame and oriented edgewise to the line of fire. The rubber strips absorb the energy of the imparting munitions leaving the projectile intact and eliminating airborne lead dust. The munitions then fall to the bottom of the trap for collection. The rubber strips require periodic replacement, the frequency depending on the amount of activity at the firing range.

   3. Granulated Munitions Trap: A granulated munitions trap consists of a steel box with a rubber front. The box contains recycled granulated rubber material, which absorbs the impact of munitions passing through the rubber front and keeps munitions intact. Periodic patching of the rubber front is required.

   4. Water Munitions Trap: A water munitions trap consists of a funnel leading to a deceleration chamber containing a small amount of water. Munitions enter the deceleration chamber, deflect downward into the water and rotate around until their energy is spent. As they spin, the munitions automatically wet the chamber, reducing the likelihood of fragmentation and airborne lead dust. The munitions then drop into a collection tray at the bottom of the trap for easy removal.

   5. Lead-free Ammunition: The U.S. Army Research, Development and Engineering Center is working on ammunition that is lead and toxin free. Currently they are evaluating a lead-free primer and lead alternatives including bismuth, molybdenum, tungsten, steel/iron and copper. Stock listed lead-free training ammunition (reduced range) is currently available in 5.56 millimeter ball and 50 caliber ball and tracer sizes.

One Note of Caution.

The Emergency Planning and Community Right-To-Know Act (EPCRA) requires reporting of hazardous substance releases which leave the base. Lead dust transported by the wind is considered a release under EPCRA. A release is reportable when more than one pound of lead particles smaller than 0.004 inches in diameter are released beyond the boundaries of the facility.

For More Information

Contact PRO-ACT at DSN 240-4214 or (800) 233-4356 for additional information on lead contamination at firing ranges or for information regarding remediation and new technologies.