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The CTS of Asheville, Inc. Superfund Site is located at 235 Mills Gap Road in Asheville, North Carolina 28803. International Resistance Company owned and operated the site from 1952 to 1959. It manufactured electronic components. CTS Corporation also manufactured electronic components used in auto parts and hearing aids at the site from 1959 to April 1986. Mills Gap Road Associates (MGRA) purchased the 53.54 acre site in 1987. MGRA sold 44.89 acres to the Biltmore Group, LLC in 1997, which developed the 44.59 acres into a residential subdivision. The remaining 8.65 acres where the old facility was located is fenced and has been vacant since the mid-1990s. The building was demolished in December 2011. The site was proposed to the National Priorities List (NPL) in March 2011 and became final on the NPL in March 2012.

EPA is the lead Federal Agency at this site, and is providing oversight of work performed by CTS Corporation and its contractor(s) under legal agreements and EPA-approved work plans.

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What Has Been Done to Clean Up the Site?

EPA’s top priority is to eliminate potential human exposure to TCE via drinking water and air inhalation pathways.

  • Removal of contaminant mass from the subsurface was initiated in 2004. A soil vapor extraction (SVE) system was installed to vacuum VOCs from the soils above the water table. From July 2006 to July 2010, the SVE system removed an estimated 6,473 pounds of VOCs from the unsaturated zone.
  • Ambient air sampling is conducted quarterly at the eastern and western springs areas.
  • From September 2012 to August 2014, CTS installed 101 water supply filtration system in residences located within a one-mile radius of the Site who relied on groundwater as their drinking water supply. The filtration systems were installed as a precautionary measure.
  • During the 2014-2015 timeframe, municipal water supply lines were installed in the vicinity of the Site by Buncombe County. Eighty-seven residences with filtration systems elected to connect to the municipal water line. The remaining water filtration systems will continue to be maintained by CTS until they are no longer warranted. Residential wells within the one-mile radius whose owners did not connect to county water service are monitored annually.
  • In September 2014, a springs remediation system was installed by CTS on property immediately to the east of the Site to reduce TCE concentrations in outdoor/indoor air. The remediation system includes a combination of air sparging and vapor extraction. Air sparging pumps air into the surface water and subsurface at seven locations. These vapors are extracted using vacuums at 12 locations and then treated by carbon canisters. The area was covered with a low-density polyethylene liner to increase the system’s efficiency. Construction began on September 10, 2014 and the system has been in continuous operation since October 21, 2014. As of mid-April 2015, the remediation system had removed approximately 42 pounds of VOCs from the environment.
  • On February 11, 2016, EPA issued an Interim Action Record of Decision (ROD) for source control that addresses contaminant mass in the saturated zone from the water table to the top of bedrock. EPA expects that the ERH and ISCO treatment strategy in the Interim Action ROD will mitigate, if not eliminate, the groundwater-to-surface water transport pathways at the eastern and western spring.

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What Is the Current Site Status?

EPA issued an Interim Action Record of Decision (ROD) on February 11, 2016, specifying the interim cleanup remedy for the site. The North Carolina Department of Environmental Quality (NCDEQ) concurred with the EPA remedy decision. The interim remedy is a source control action for Non-Aqueous Phase Liquid (NAPL) and trichloroethene (TCE) in the groundwater beneath the former CTS plant site. The interim action will address a 3.1-acre area. Approximately 208,250 cubic yards (CYs) of material in the saturated zone between the observed water table and top of competent bedrock will be cleaned up. The major components of the selected interim remedy include:

  • Electrical Resistance Heating (ERH) to treat the mixed NAPL and TCE plume in an approximate 1.2-acre area. ERH will address about 47,250 CYs of saturated material contaminated by NAPL/TCE.
  • In-Situ Chemical Oxidation (ISCO) to treat the TCE-only contamination in an area to the north of the area being treated by ERH. The volume of this 1.9-acre treatment area is approximately 161,000 CYs.
  • Monitoring will be conducted while the remedy is implemented to ensure adequate protection of on-site workers and the surrounding community. Performance data will be collected to demonstrate the effectiveness of the interim remedy in meeting the Remedial Action Objective, which is a 95% reduction in the TCE concentration. Groundwater will also be monitored to evaluate the anticipated decreasing concentration of TCE in the deeper bedrock aquifer over time.

The total estimated cost of the interim remedy is about $9 million. EPA expects to work with the potentially responsible parties to reach a legal agreement to implement the work specified in the Interim Action ROD. Design and implementatation of the interim remedy began in 2017. 

This interim remedy will be followed by a final site-wide cleanup decision that is not expected for several years. EPA and the potentially responsible parties will complete the Remedial Investigation/Feasibility Study to evaluate options for the final remedy. EPA will then propose the plan to the public for its input before selecting the final remedy for the site. It is important to gauge the success of the interim remedy before selecting the final remedy.

EPA distributes community updates periodically to provide information on current site activities.

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Sampling and Monitoring

In June 2015, additional data was collected on the western side of the site, near the Southside Village neighborhood and an undeveloped tract of land south of Mills Gap Road. This investigation delineated a narrow plume of TCE-impacted groundwater extending from the western fence line of the CTS plant site. The results of this data collection are compiled in the Western Area Remedial Investigation Report and Addendum.

Drinking water is sampled annually at homes where the owners declined to connect to the extended municipal water line. Air is sampled several times a year to ensure the treatment system is working as intended.

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Enforcement Information

In 2004, EPA entered into an Administrative Order on Consent (AOC) for Removal Action with CTS Corporation, the former operator at the time of disposal for the Site, and Mills Gap Road Associates, the current owner of the Site. On January 26, 2012, EPA and CTS Corporation entered into an Administrative Order and Settlement Agreement on Consent (AOC) for Remedial Investigation and Feasibility Study (RI/FS).

On May 10, 2016, EPA issued Special Notice Letters to three Potentially Responsible Parties (PRPs) at the CTS of Asheville, Inc. Superfund Site: Mills Gap Road Associates; CTS Corporation; and Northrop Grumman Systems Corporation. Issuing Special Notice Letters is an important first step in the legal process by which the EPA formally requests that PRPs perform remedial work at a site under EPA oversight and according to EPA-approved work plans. The Interim Remedial Action for the CTS of Asheville, Inc. Superfund Site was selected by the EPA in a Record of Decision (ROD) finalized on February 11, 2016. The Interim Remedial Action calls for a combination of Electrical Resistance Heating (ERH) and In-Situ Chemical Oxidation (ISCO) treatment to address Non-Aqueous Phase Liquid (NAPL) and trichloroethene (TCE) beneath 3.1 acres of the former CTS facility. The estimated cost of this interim source control remedy is approximately $9 Million.

On March 7th, the judge signed the settlement agreement for the Interim Remedial Action at the CTS of Asheville, Inc. Superfund Site. 

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