Fact Sheet
Solid Waste Management Unit 54
November 2007

Solid Waste Management Unit 54

Introduction

This fact sheet describes the recommended action for contaminated soil and groundwater at Solid Waste Management Unit (SWMU) 54 – Propellant Burning Ash Disposal Area at Radford Army Ammunition Plant (RFAAP).  This alternative was recommended in accordance with the Resource Conservation and Recovery Act of 1976 (RCRA), the Hazardous and Solid Waste Amendments of 1984 (HSWA), the RFAAP RCRA permit requirements (USEPA, 2000) (EPA ID No. VA1210020730), and the Final RCRA Corrective Action Plan (USEPA, 1994), as applicable.

Background

SWMU 54 is a former disposal area situated on approximately 5 acres within the easternmost section of the Horseshoe Area.  In the late 1970s, ash from propellant burning operations at SWMU 13 was reportedly disposed of at the site.  Propellant ash is a residue resulting from the burning of waste explosives, propellants, and laboratory wastes.  The SWMU consists of two non-contiguous areas (Area A and Area B).  Area A is an approximate 0.58-acre (approximately 100 by 320 feet (ft)), triangular shaped disposal area in the southeastern portion of the site.  Area B is an approximate 1.09-acre area (approximately 240 by 240 ft) in the northwestern portion of the site. 

The RFAAP RCRA Corrective Action Permit identified SWMU 54 as an area of concern that had the potential to pose a threat or potential threat to human health and the environment.  In 1999 an interim measure was conducted at Area A and Area B of SWMU 54 which consisted of the excavation of “hot spot” areas of lead and explosives in soil.  Approximately 1,827 tons of soil were excavated and disposed offsite at the Pinewood South Carolina Landfill.  Based on the results of the interim actions, additional investigation of both Area A and Area B was planned to confirm the effectiveness of the interim action, as well as, evaluate and assess current conditions at the sites and provide recommendations regarding potential corrective measure requirements at the sites.

These additional RCRA facility investigation (RFI) field efforts were conducted from 2002 through 2007.  The primary site-related chemicals of concern identified in soil at the site are those associated with propellant ash including lead, explosives, and dioxins.  Explosives and perchlorate were detected in site groundwater at levels of concern, with the release occurring from Area A.  Groundwater impacts were not detected at disposal unit wells at Area B at levels of concern.  Due to the nature and extent of the chemicals of potential concern (COPCs) at the sites and the presence of contaminants in groundwater, the corrective measures assessed for the sites focused on the soil migration to groundwater pathway which was determined to be protective of groundwater and surface water of the adjacent New River, as well as, human and ecological receptors.

Remedial Alternatives

Three corrective measures technologies were assessed in the Corrective Measures Study (CMS) for development of two corrective measures alternatives in addition to a baseline no further action alternative including:

• Alternative No. 1: No Further Action;
• Alternative No. 2: Excavation of Soil at Area A and Area B, Offsite Disposal, and Monitored Natural Attenuation (MNA) of Groundwater; and
• Alternative No. 3: Excavation of Soil at Area A and Area B, Offsite Disposal, and Enhanced In Situ Bioremediation of Groundwater.

These three alternatives were evaluated using the following criteria:  effectiveness, implementability, and cost.  Alternative Two was recommended as the final alternative for SWMU 54 because it will effectively achieve the corrective measures objectives (CMOs) and remedial goals (RGs) while also providing for future unrestricted use of the site.  Removal of the soil source areas will prevent future leaching of COPCs to groundwater and allow for continued attenuation of COPCs in groundwater to levels at or below RGs; thereby restoring groundwater.  In addition, implementation of Alternative Two will not result in potential adverse effects to groundwater (i.e., degradation of secondary water quality parameters) from remedial implementation activities, which would occur with implementation of Alternative Three. 

The soil component of Alternative Two is expected to be completed in less than one year.  Monitored natural attenuation (MNA) is expected to require five years or less of performance groundwater monitoring to demonstrate achievement of CMOs and RGs.  For purposes of the CMS, an additional three years of monitoring has been assumed to demonstrate continued achievement of CMOs and RGs before site closeout.  This time frame is considered an estimate and the actual time to complete the corrective measures will be subject to site-specific conditions. 

Implementation of Alternative Two will include the following:

• Pre-characterization of waste;
• Excavation of soil from Area A and Area B so that remaining soil is at or below the RGs;
• Transportation and offsite disposal of soil;
• Site restoration of excavation areas including backfilling, grading, seeding, etc.;
• Installation of supplemental monitoring network for MNA of groundwater;
• Quarterly performance groundwater monitoring and annual monitoring of surface water/sediment pore water of the New River until achievement and maintenance of RGs; and
  Closeout/abandonment of site monitoring wells.

The data, findings, assessments, and recommendations are contained in the SWMU 54 RFI Report, October 2007, and is currently being reviewed by the U.S. Army Environmental Center (USAEC), U.S. Environmental Protection Agency (USEPA) Region III, and the Virginia Department of environmental quality (VDEQ).

For more information, please contact Mr. Jim McKenna, RFAAP Restoration Manager, by phone 540-639-8641 or by Email: Jim McKenna