An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »

Hazardous Waste Cleanup: Merck Sharpe and Dohme Corporation - Stonewall Plant in Elkton, Virginia

On this page:

Resource Conservation and Recovery Act (RCRA) Corrective Action clean-up activities at the facility are implemented through the conditions and requirements of the facility's Hazardous Waste Management Permit for Site Wide Corrective Action (Permit), issued on April 5, 2002, and the facility's Corrective Measures Implementation (CMI) Work Plan, approved on September 8, 2004.

    Cleanup Status


    Merck continues to operate and maintain bioventing remediation systems at Area of Concern (AOC) North and AOC South to reduce Volatile Organic Compound (VOCs) and Semvolatile Organic Compound (SVOCs) in soil and groundwater. The remedy for AOC South includes a soil vapor extraction (SVE) component in addition to bioventing, but is currently not utilized due to the effectiveness of bioventing. In addition, Merck maintains a biosparge system at the Landfill AOC, but is performing a pilot test study using solid phase peroxide as a passive approach due to the formation of sinkholes directly related to biosparging. It is anticipated that final results of the pilot test will be available by the end of 2010.

    Additionally, Merck continues groundwater sampling associated with Monitored Natural Attenuation (MNA) at the Skimmer Pond, Solvent Burning Pit, and Waste Pit SWMUs. However, in response to increasing VOC concentrations at the Skimmer Pond Merck is implementing a pilot test study to enhance biodegradation of VOCs by reductive dechloronation via groundwater amendment. This consists of extracting groundwater, amending the extracted groundwater with an emulsified soybean oil and bacteria culture, and re-injecting the amended groundwater back into the aquifer. During the pilot test, groundwater quality will be monitored in addition to select indicator parameters, VOCs, and SVOCs. It is anticipated that the pilot test will be implemented by the end of July 2010 and will take up to a year to complete.

    On July 1, 1999 a Corrective Action Statement of Basis was issued with controls.

      Top of Page

      Site Description

      Interactive Map of Merck Sharp & Dohme Corporation - Stonewall Plant, Elkton, VA

      View larger map

      The Merck facility is located in northwestern Virginia, approximately two miles southwest of Elkton. The facility property lies within the Shenandoah Valley, just southeast of the South Fork of the Shenandoah River. The facility occupies approximately 1,300 acres, of which 89 acres are used for active operation. The facility began operation in 1941. Prior to that, the land was undeveloped. The facility includes a pharmaceutical laboratory and manufacturing facilities, which produce animal and human health care products (pharmaceuticals). The facility is permitted to store hazardous wastes in containers and is currently in the Corrective Measures Implementation (CMI) phase of RCRA Corrective Action.

      The facility is supported by a wastewater treatment plant, a solvent recovery operation, and a power plant with co-generation facilities. Additionally, there is an onsite, permitted, industrial landfill. The landfill occupies 7 acres located in the northeastern corner of the property. Prior to 1980 various production wastes, including organic and inorganic chemicals from the plant operations were disposed of in the landfill. The landfill was capped in 2000 as a required corrective measure and a deed notice was put in place identifying its location. Onsite groundwater flow is controlled by continuous production well pumping at the facility.

      On June 15, 2010 and in response to increasing VOC concentrations at the Skimmer Pond, the  Virginia Department of Environmental Quality (VA DEQ) approved the performance of a pilot test study for one year to evaluate the effectiveness of groundwater amendment activities in efforts of increasing reductive dechloronation of VOCs via introduction of emulsified soybean oil and cultured bacteria.

      As part of Merck's Community Relations Plan, citizens' questions and concerns are addressed throughout the RCRA Corrective Action process via annual community information sharing sessions at the Elkton Elementary School. In addition, Merck regularly issues community newsletters highlighting remediation progress.

      Top of Page

      Contaminants at this Facility

      The primary contaminants of concern in groundwater include benzene, chlorobenzene, chloroform, methylene chloride, naphthalene, trichloroethene, vinyl chloride, and vanadium. The constituents of concern in surface and subsurface soils include several VOCs and SVOCs.

      Top of Page

      Institutional and Engineering Controls at this Facility

      Institutional /Engineering Control Summary
      Restrictions or Controls that Address: Yes No
      Groundwater Use
      Residential Use
      Vapor Intrusion
      Capped Area(s)
      Other Engineering Controls
      Other Restrictions

      Institutional Controls (IC) and Engineerting Controls (EC) for the site include:

      • IC: Prohibition on the use of groundwater for potable uses.
      • IC: Site is only for non-residential use.
      • EC: A hazardous waste cap was installed over the sanitary landfill which also has restrictions on future use or disturbance on the cap.
      • EC: Site wide groundwater extraction sytem and the AOC (Area of Concern) North ( Skimmer Pond) also has a groundwater treatment system.
      • EC: The AOC South has Soil Treatment restrictions.

        Top of Page

      Land Reuse Information at this Facility

      The facility is under continued use.

      Top of Page

      Site Responsibility at this Facility

      RCRA Corrective Action activities at this facility are being conducted under the direction of the EPA Region 3 with assistance from the VA DEQ.

      Top of Page