1. J-Field Edgewood Aberdeen Proving Ground

2. Description From 1940 to 1970s, the Army disposed of chemical agents, high explosives and chemical wastes. APG currently uses the area for emergency disposal of unstable range-recovered munitions under an interim permit from EPA. All emergency disposals are coordinated and approved by Maryland Department of the Environment and the U.S. Department of Health and Human Services. A remedial investigation (RI) and feasibility study (FS) that was initiated in 1992. For this study, J- Field was divided into 8 Areas of Concern (AOC) on the basis of known activities in APG.

3. Toxic Burning Pits White Phosphorus Burning Pits Riot Control Burning Pits Robins Point Demolition Ground Robins Point Tower Site South Beach Demolition Ground South beach Trench Prototype Building

4. Toxic Burning Pits Five disposal pits were used at the TBP AOC as well as a storage area, a disposal area, and a demolition area. The two existing (or main) burning pits were most actively used for disposal of various chemical agents and explosives. The other pits, now covered, were used to dispose of VX, mustard, and liquid smoke components. T The main disposal pits were maintained by periodically pushing burned soil and ash toward the marsh area, creating what is referred to as the "Pushout Area." This area extends more than 30 m into the adjacent marsh.

5. Possible Solutions (Retained) Institutional Control (Access restriction/monitoring) In-situ containment (surface control/ barriers/caps & covers) Removal (excavation/clearing) Ex-situ treatment (stabilization/soil washing & leaching/incineration/thermal desorption) Short term storage (open and closed structures) Disposal (Land-based facility)

6. Possible Solutions (Rejected) In-situ treatment (soil flushing/stabilization/vitrification) Ex-situ treatment (vitrification/reduction & oxidation/dehalogenation) Biological treatment (in-situ bioremediation/ex-situ bioremediation)

7. J-Field Confined Aquifer TI Evaluation - Alternative Remedial Strategy (ARS) was developed to reduce risk to human health and the environment at the J-Field Study Area. This ARS includes: - Establishing Institutional Controls - The continuation of phytoremediation - Monitoring biodegradation processes -Abandonment and replacement of Confined Aquifer well -Possible addition of a supplement to the replacement well -Continued monitoring of the Confined Aquifer -Implementation of free phase DNAPL recovery in the localized area where DNAPL was observed

8. The goal of this remedy is to reduce the contaminant mass in the J-Field Surficial Aquifer through DNAPL recovery, phytoremediation, and natural processes, to eliminate exposure to the groundwater and to control off-site contaminant migration from the Confined Aquifer.